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Power Engineering Guide Transmission and Distribution

4th Edition

Power Engineering Guide Transmission and Distribution

Your local representative:

Sales locations worldwide (EV): http://www.ev.siemens.de/en/pages/salesloc.htm

Distributed by: Siemens Aktiengesellschaft Power Transmission and Distribution Group International Business Development, Dept. EV IBD P.O. Box 3220 D-91050 Erlangen Phone: ++ 49 - 9131-73 45 40 Fax: ++ 49-9131-73 45 42 Power Transmission and Distribution group online: http://www.ev.siemens.de

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Foreword

This Power Engineering Guide is devised as an aid to electrical engineers who are engaged in the planning and specifying of electrical power generation, transmission, distribution, control, and utilization systems. Care has been taken to include the most important application, performance, physical and shipping data of the equipment listed in the guide which is needed to perform preliminary layout and engineering tasks for industrial and utility-type installations. The equipment listed in this guide is designed, rated, manufactured and tested in accordance with the International Electrotechnical Commission (IEC) recommendations. However, a number of standardized equipment items in this guide are designed to take other national standards into account besides the above codes, and can be rated and tested to ANSI/ NEMA, BS, CSA, etc. On top of that, we manufacture a comprehensive range of transmission and distribution equipment specifically to ANSI/NEMA codes and regulations. Two thirds of our product range is less than five years old. For our customers this means energy efficiency, environmental compatibility, reliability and reduced life cycle cost. For details, please see the individual product listings or inquire. Whenever you need additional information to select suitable products from this guide, or when questions about their application arise, simply call your local Siemens office.

Siemens AG is one of the world’s leading international electrical and electronics companies. With 416 000 employees in more than 190 countries worldwide, the company is divided into various Groups. One of them is Power Transmission and Distribution. The Power Transmission and Distribution Group of Siemens with 24 700 employees around the world plans, develops, designs, manufactures and markets products, systems and complete turn-key electrical infrastructure installations. The group owns a growing number of engineering and manufacturing facilities in more than 100 countries throughout the world. All plants are, or are in the process of being certified to ISO 9000/9001 practices. This is of significant benefit for our customers. Our local manufacturing capability makes us strong in global sourcing, since we manufacture products to IEC as well as ANSI/NEMA standards in plants at various locations around the world. Siemens Power Transmission and Distribution Group (EV) is capable of providing everything you would expect from an electrical engineering company with a global reach. The Power Transmission and Distribution Group is prepared and competent, to perform all tasks and activities involving transmission and distribution of electrical energy.

Sales locations worldwide: http://www.ev.siemens.de/en/pages/ salesloc.htm

Siemens Power Transmission and Distribution Group offers intelligent solutions for the transmission and distribution of power from generating plants to customers. The Group is a product supplier, systems integrator and service provider, and specializes in the following systems and services: ■ High-voltage systems ■ Medium-voltage systems ■ Metering ■ Secondary systems ■ Power systems control and energy management ■ Power transformers ■ Distribution transformers ■ System planning ■ Decentralized power supply systems. Siemens’ service includes the setting up of complete turnkey installations, offers advice, planning, operation and training and provides expertise and commitment as the complexity of this task requires. Backed by the experience of worldwide projects, Siemens can always offer its customers the optimum cost-effective concept individually tailored to their needs. We are there – wherever and whenever you need us – to help you build plants better, cheaper and faster.

Dr. Hans-Jürgen Schloß Vice President Siemens Aktiengesellschaft Power Transmission and Distribution

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Quality and Environmental Policy

Quality and Environmental – Our first priority Transmission and distribution equipment from Siemens means worldwide activities in engineering, design, development, manufacturing and service. The Power Transmission and Distribution Group of Siemens AG, with all of its divisions and relevant locations, has been awarded and maintains certification to DIN EN ISO 9001 and DIN EN ISO 14001. Certified quality Siemens Quality Management and Environmental Management System gives our customers confidence in the quality of Siemens products and services. Certified to be in compliance with DIN EN ISO 9001 and DIN EN ISO 1400, it is the registered proof of our reliabilty.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Contents General Introduction Energy Needs Intelligent Solutions

Power Transmission Systems

1

High Voltage

2

Medium Voltage

3

Low Voltage

4

Transformers

5

Protection and Substation Control

6

Power Systems Control and Energy Management

7

Metering

8

Services

9

System Planning

10

Conversion Factors and Tables Contacts and Internet Addresses Conditions of Sales and Delivery

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

General Introduction

Energy management systems are also important, to ensure safe and reliable operation of the transmission network. Distribution In order to feed local medium-voltage distribution systems of urban, industrial or rural distribution areas, HV/MV main substations are connected to the subtransmission systems. Main substations have to be located next to the MV load center for reasons of economy. Thus, the subtransmission systems of voltage levels up to 145 kV have to penetrate even further into the populated load centers. The far-reaching power distribution system in the load center areas is tailored exclusively to the needs of users with large numbers of appliances, lamps, motor drives, heating, chemical processes, etc. Most of these are connected to the low-voltage level. The structure of the low-voltage distribution system is determined by load and reliability requirements of the consumers, as well as by nature and dimensions of the area to be served. Different consumer characteristics in public, industrial and commercial supply will need different LV network configurations and adequate switchgear and transformer layout. Especially for industrial supply systems with their high number of motors and high costs for supply interruptions, LV switchgear design is of great importance for flexible and reliable operation. Independent from individual supply characteristics in order to avoid uneconomical high losses, however, the substations with the MV/LV transformers should be located as close as possible to the LV load centers. The compact load center substations should be installed right in the industrial production area near to the LV consumers. The superposed medium-voltage system has to be configured to the needs of these substations and the available sources (main substation, generation) and leads again to different solutions for urban or rural public supply, industry and large building centers. In addition distribution management systems can be tailored to the needs, from small to large systems and for specific requirements.

Main substation with transformers up to 63 MVA HV switchgear

MV switchgear

Local medium-voltage distribution system

Feeder cable

Spot system

Connection of large consumer

Industrial supply and large buildings

Ring type Public supply

Medium voltage substations MV/LV substation looped in MV cable by load-break switchgear in different combinations for individual substation design, transformers up to 1000 kVA LV fuses

Circuitbreaker Loadbreak switch Consumer-connection substation looped in or connected to feeder cable with circuitbreaker and load-break switches for connection of spot system in different layout

MV/LV transformer level

Low-voltage supply system Public supply with pillars and house connections internal installation

Large buildings with distributed transformers vertical LV risers and internal installation per floor

Consumers

Fig. 2: Distribution: Principle configuration of distribution systems

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Industrial supply with distributed transformers with subdistribution board and motor control center

General Introduction

Despite the individual layout of networks, common philosophy should be an utmost simple and clear network design to obtain ■ flexible system operation ■ clear protection coordination ■ short fault clearing time and ■ efficient system automation. The wide range of power requirements for individual consumers from a few kW to some MW, together with the high number of similar network elements, are the main characteristics of the distribution system and the reason for the comparatively high specific costs. Therefore, utmost standardization of equipment and use of maintenance-free components are of decisive importance for economical system layout. Siemens components and systems cater to these requirements based on worldwide experience in transmission and distribution networks. Protection, operation, control and metering Safe, reliable and economical energy supply is also a matter of fast, efficient and reliable system protection, data transmission and processing for system operation. The components required for protection and operation benefit from the rapid development of information and communication technology. Modern digital relays provide extensive possibilities for selective relay setting and protection coordination for fast fault clearing and minimized interruption times. Remote Terminal Units (RTUs) or Substation Automation Systems (SAS) provide the data for the centralized monitoring and control of the power plants and substations by the energy management system. Siemens energy management systems ensure a high supply quality, minimize generation and transmission costs and optimally manage the energy transactions. Modularity and open architecture offer the flexibility needed to cope with changed or new requirements originating e.g. from deregulation or changes in the supply area size. The broad range of applications includes generation control and scheduling, management of transmission and distribution networks, as well as energy trading. Metering devices and systems are important tools for efficiency and economy to survive in the deregulated market. For example, Demand Side Management (DSM) allows an electricity supply utility from a control center to remotely control certain consumers on the supply network for load control purposes. Energy meters are used for measuring the consumption of electricity, gas, heat and water for purposes of billing in the fields of households, commerce, industry and grid metering.

Power system substation Power system switchgear Bay protection – Overcurrent – Distance – Differential etc. Other bays

Bay switching interlocking Control Other bays

Bay coordination level

Substation coordination level BB and BF (busbar and breaker failure) protection

Substation control

Switchgear interlocking

Data and signal input/output

Data processing Automation Metering

Power network telecommunication systems

Other substations

Power line carrier communication

Other substations

Fiber-optic communication

System coordination level SCADA functions

Power and scheduling applications

Distribution management functions Grafical information systems

Network analysis

Training simulator

Control room equipment

Fig. 3: System Automation: Principle configuration of protection, control and communication systems Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

General Introduction

Overall solutions – System planning Of crucial importance for the quality of power transmission and distribution is the integration of diverse components to form overall solutions. Especially in countries where the increase in power consumption is well above the average besides the installation of generating capacity, construction and extension of transmission and distribution systems must be developed simultaneously and together with equipment for protection, supervision, control and metering. Also, for the existing systems, changing load structures, changing requirements due to energy market deregulation and liberalization and/ or environmental regulations, together with the need for replacement of aged equipment will require new installations. Integral power network solutions are far more than just a combination of products and components. Peculiarities in urban development, protection of the countryside and of the environment, and the suitability for expansion and harmonious integration in existing networks are just a few of the factors which future-oriented power system planning must take into account. Outlook The electrical energy supply (generation, transmission and distribution) is like a pyramid based on the number of components and their widespread use. This pyramid rests on a foundation formed by local expansion of the distribution networks and power demand in the overall system, which is determined solely by the consumers and their use of light, power and heat. These basic applications arise in many variations and different intensities throughout the entire private, commercial and industrial sector (Fig. 4). Reliability, safety and quality (i.e. voltage and frequency stability) of the energy supply are therefore absolute essentials and must be assured by the distribution networks and transmission systems.

Generation Transmission Distribution Consumers

Applications

Light

Power

Monitoring, Control, Automation

Fig. 4: Industrial applications

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Heat

Energy Needs Intelligent Solutions

The changing state of the world’s energy markets and the need to conserve resources is promoting more intelligent solutions to the distribution of man’s silent servant, electricity. Change is generally wrought by necessity, often driven by a variety of factors, not least social, political, economic, environmental and technological considerations. Currently the world’s energy supply industries – principally gas and electricity – are in the process of undergoing radical and crucial change that is driven by a mixture of all these considerations. The collective name given to the factors affecting the electricity supply industry worldwide is deregulation. This is the changing operating scenario the electricity supply industry as a whole faces as it moves inexorably into the 21st century. How can it rise to the challenge of liberalized markets and the opportunities presented by deregulation? One of the answers is the better use of information technology and “intelligent” control to affect the necessary changes born of deregulation. However, to achieve this utilities need to be very sure of the technical and commercial competence of their systems suppliers. Failure could prove to be very costly not just in financial terms, but also for a utility’s reputation with its consumers in what is becoming increasingly a buyer’s market. Forming and maintaining close partnerships with long-established systems suppliers such as Siemens is the best way of ensuring success with deregulation into the millennium. Siemens can look back on over 100 years of working in close co-operation with power utilities throughout the world. This accumulated experience allows the company’s Power Transmission and Distribution Group to address not just technical issues, but also better appreciate many of the operational and commercial aspects of electricity distribution. Experience gained over the past decade with the many-and-varied aspects of deregulation puts the Group in an almost unique position to advise utilities as to the best solutions for taking full advantage of the opportunities offered by deregulation. Innovation the issue of change Although today’s technology obviously plays a very important role in the company’s current business, innovation has always been at the vanguard of its activities; indeed it is the common thread that has run through the company since its inception 150 years ago. In future power distribution technology, computer software, power electronics and superconductivity will play increasingly prominent roles in innovative solutions. Scope for new technol-

Fig. 5: Superconducting current limiter: lightning fast response

ogies is to be found in decentralized energy supply concepts and in meeting the needs of urban conurbations. Siemens is no longer just a manufacturer of systems and equipment, it is now much more. Overall concepts are becoming ever more important. All change! Power distribution technology has not changed significantly over the past forty years… indeed, the “rules of the game” have remained the same for a much longer period of time. A new challenge Recently decentralized power supply systems have cornered a growing share of the market for a number of reasons. In developing and industrializing countries, it has become clear that the energy policies and systems solutions adopted by nations with well-established energy infrastructures are not always appropriate. Frequently it is more prudent to start with small decentralized power networks and to expand later in a progressive way as demand and economics permit. Much benefit can also be gained if generation makes use of natural or indigenous resources such as the sun, water, wind or biomass. Countries that struggle with population growth and migration to the towns and cities clearly need to pay close attention to protecting their balance of payments. In such cases, the expansion of power supplies into the countryside

is a crucial factor in the economic and social development of a particular country. In the industrialized countries the concept of the “decentralized power supply” is also gaining ground, largely because of environmental concern. This has had its consequences for the generation of electricity: wind power is experiencing a renaissance, more development work is being carried out into photovoltaic devices and combined heat and power cogeneration plants are growing in popularity in many areas for both ecological and economic reasons. These developments are resulting in some entirely new energy network structures. Additional tasks... The scope and purpose of tomorrow’s distribution systems will no longer be to simply “supply electricity”. In future they will be required to “harvest” power and redistribute it more economically and take into account, among other considerations, environmental needs. In the past it was no easy task to supply precisely the right amount of electricity according to demand because, as is well-known, electricity cannot be readily stored and the loads were continually changing. Demand scheduling was very much based on statistical forecasting – not an exact science and one that cannot by its very nature take into account realtime variations. Demand scheduling problems can become particularly acute when power stations of limited generating capacity are on line.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Energy Needs Intelligent Solutions

Nowadays these and similar problems are not insoluble because of decentralized power supplies and the use of “intelligent” control. The Power Transmission and Distribution Group has developed concepts for the economic resolution of peak energy demand. One is to use energy stores. Batteries are an obvious choice, for these can be equipped with power electronics to enhance energy quality as well as storing electricity. Intelligent energy management… One of the options for matching the amount of electricity available to the amount being demanded is, even today, the rarely used technique of load control. Energy saving can mean much more than just consuming as few kilowatt-hours as possible. It can also mean achieving the flexibility of demand that can make a valuable contribution to a country’s economy. Naturally, in places such as hospitals, textile factories and electronic chip fabrication plants it is extremely important for the power supply not to fail – not even for a second. In other areas of electricity consumption, however, there is much more room for manoeuvre. Controlled interruptions of a few minutes, and even a few hours, can often be tolerated without causing very much difficulty to those involved. There are other applications where the time constant or resilience is high, e.g. cold stores and air-conditioning plants, where energy can be stored for periods of up to several hours. Through the application of “intelligent” control and with suitable financial encouragement (usually in the form of flexible tariff rates) there is no doubt that very much more could be made of load control. Improving energy quality… Power electronics systems, for example SIPCON, can help improve energy quality – an increasingly important factor in deregulated energy markets. Energy has now become a product. It has its price and a defined quality. Consumers want a definite quality of energy, but they also produce reaction effects on the system that are detrimental to quality (e.g. harmonics or reactive power). Energy quality first has to be measured and documented, for example with the SIMEAS® family of quality recorders. These measurements are important for price setting, and can serve as the basis for remedial action, such as with active or passive filters. Power electronics development has opened up many new possibilities here, although considerable progress may still be made in this area – a breakthrough in silicon carbide technology, for example.

Fig. 6: Silicon carbide

Fig. 7: GIL

Alternatives… It should be appreciated, however, that decentralized power supplies are not a panacea. For those places where energy density requirements are high, large power stations are still the answer, and especially when they can supply district heating. Theoretically, it should still be possible to employ conventional technology to transport very large amounts of electricity to the megacities of the 21st Century. Even if the use of overhead power lines was not an option, due to say there being insufficient space or

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

resistance from people living nearby, it would be possible to use gas-insulated lines (GIL), an economical alternative investigated by Siemens. The development aim of reducing costs has meanwhile been attained here, and costeffective applications involving distances of serveral kilometres are therefore possible. The system costs for the gas-insulated transmission lines (GIL) developed by Siemens exceed those of overhead lines only by about a factor of 10.

Energy Needs Intelligent Solutions

Energy management via satellite

Long-distance DC transmission Wind energy Solar energy

Power plants Converter station

Pumping station

Irrigation system

Biomass power plant

Switching station

Fuel cells

Energy store GIL

Distribution station

Cooling station (liquid nitrogen)

Fig. 8: The mega-cities of the 21st century and the open countryside will need different solutions – very high values of connection density in the former and decentralised configurations in the latter

This has been achieved by laying the tubular conductor using methods similar to those employed with pipelines. Savings were also made by simplifying and standardizing the individual components and by using a gas mixture consisting of sulfur hexafluoride (SF6) and nitrogen (N2). The advantages of this new technology are low resistive and capacitive losses. The electric field outside of the enclosure is zero, and the magnetic field is negligibly small. No cooling and no phase angle compensation are required. GILs are not a fire hazard and are simple to repair.

ers are demanding a more reasonable return on their investment. Deregulation generally means privatization; profit orientation is therefore clearly going to take over from concern with cost. In addition this means that competition will inevitably produce some concessions in the price of electricity, which will increase the pressure on energy suppliers. Many power supply companies are striving to introduce additional energy services, thereby making the pure price of energy not the only yardstick their customers apply when deciding how to make their purchases.

Energy trade The new “rules of the game” that are being introduced in power supply business everywhere are demanding more capability from utility IT systems, especially in areas such as energy trading. Siemens has been in the fortunate position of being able to accumulate early practical experience in this field in markets where deregulation is being introduced very quickly – such as the United Kingdom, Scandinavia and the USA – and so is now able to offer sophisticated systems and expertise with which utilities can get to grips with the demands of the new commercial environment. In the past it was always security of supply that took the highest priority for a utility. Now, however, although it remains an important subject, more and more sharehold-

Siemens – the energy systems house Siemens is offering solutions to the problems that are governed by the new “rules of the game”. The company possesses considerable expertise, mainly because it is a global player, but also because it covers the total spectrum of products necessary for the efficient transmission and distribution of electricity. As with other Groups within the company, Power Transmission and Distribution no longer regards itself as simply a purveyor of hardware. In future Siemens will be more of a provider of services and total solutions. This will mean embracing many new disciplines and skills, not least financial control and complete project management. One of the reasons is that in future “BOT” (Build, Operate & Transfer) compa-

nies and independent operating utilities will no longer confine their activities to just energy production; they will be expected to become increasingly involved in energy distribution too. Potential for the future The ongoing development of high-temperature superconductors will doubtless enable much to be achieved. Major operational innovations will, nonetheless, come from the more pervasive use of communications and data systems – two areas of technology where innovations can be seen every 18 months. Consequently, it will be from these areas that the enabling impetus for significant advances in power engineering will come.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

High Voltage

Contents

Page

Introduction ...................................... 2/2 Air-Insulated Outdoor Substations ....................... 2/4 Circuit-Breakers General ............................................. 2/10 Circuit-Breakers 72 kV up to 245 kV .......................... 2/12 Circuit-Breakers 245 kV up to 800 kV ........................ 2/14 Live-Tank Circuit-Breakers .......... 2/16 Dead-Tank Circuit-Breakers ........ 2/20 Surge Arresters .............................. 2/24 Gas-Insulated Switchgear for Substations Introduction ..................................... 2/28 Main Product Range ..................... 2/29 Special Arrangements .................. 2/33 Specification Guide ....................... 2/34 Scope of Supply ............................. 2/37 Gas-insulated Transmission Lines (GIL) .............. 2/38 Overhead Power Lines ................. 2/40 High-Voltage Direct Current Transmission .................... 2/49 Power Compensation in Transmission Systems .................. 2/52

2

High-Voltage Switchgear for Substations

Introduction 1

2

3

4

5

6

7

8

9

High-voltage substations form an important link in the power transmission chain between generation source and consumer. Two basic designs are possible: Air-insulated outdoor switchgear of open design (AIS) AIS are favorably priced high-voltage substations for rated voltages up to 800 kV which are popular wherever space restrictions and environmental circumstances do not have to be considered. The individual electrical and mechanical components of an AIS installation are assembled on site. Air-insulated outdoor substations of open design are not completely safe to touch and are directly exposed to the effects of weather and the environment (Fig. 1).

Fig. 1: Outdoor switchgear

Gas-insulated indoor or outdoor switchgear (GIS) GIS compact dimensions and design make it possible to install substations up to 550 kV right in the middle of load centers of urban or industrial areas. Each circuitbreaker bay is factory assembled and includes the full complement of isolator switches, grounding switches (regular or make-proof), instrument transformers, control and protection equipment, interlocking and monitoring facilities commonly used for this type of installation. The earthed metal enclosures of GIS assure not only insensitivity to contamination but also safety from electric shock (Fig. 2). Gas-insulated transmission lines (GIL) A special application of gas-insulated equipment are gas-insulated transmission lines (GIL). They are used where high-voltage overhead lines are not suitable for any reason. GIL have a high power transmission capability, even when laid underground, low resistive and capacitive losses and low electromagnetic fields.

10

Fig. 2: GIS substations in metropolitan areas

2/2

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

High-Voltage Switchgear for Substations

Turnkey Installations High-voltage switchgear is normally combined with transformers and other equipment to complete transformer substations in order to ■ Step-up from generator voltage level to high-voltage system (MV/HV) ■ Transform voltage levels within the high-voltage grid system(HV/HV) ■ Step-down to medium-voltage level of distribution system (HV/MV)

Major components, e.g. transformer Substation Control Control and monitoring, measurement, protection, etc.

Structural Steelwork Gantries and substructures

Design

AC/DC es ri auxililia

we

rc

ab les Contro l and signal c ables

Ancillary equipment

Po

rge s Su erter div g in rth e m a E st sy

2

Civil Engineering Buildings, roads, foundations

3

Fire protection Env iron pro menta tec tion l Li gh tn in g

4

ion lat n ti Ve frequ. Carrier- ent equipm

The High Voltage Division plans and constructs individual high-voltage switchgear installations or complete transformer substations, comprising high-voltage switchgear, medium-voltage switchgear, major components such as transformers, and all ancillary equipment such as auxiliaries, control systems, protective equipment, etc., on a turnkey basis or even as general contractor. The spectrum of installations supplied ranges from basic substations with single busbar to regional transformer substations with multiple busbars or 1 1/2 circuit-breaker arrangement for rated voltages up to 800 kV, rated currents up to 8000 A and short-circuit currents up to 100 kA, all over the world. The services offered range from system planning to commissioning and after-sales service, including training of customer personnel. The process of handling such an installation starts with preparation of a quotation, and proceeds through clarification of the order, design, manufacture, supply and cost-accounting until the project is finally billed. Processing such an order hinges on methodical data processing that in turn contributes to systematic project handling. All these high-voltage installations have in common their high-standard of engineering, which covers power systems, steel structures, civil engineering, fire precautions, environmental protection and control systems (Fig. 3). Every aspect of technology and each work stage is handled by experienced engineers. With the aid of high-performance computer programs, e.g. the finite element method (FEM), installations can be reliably designed even for extreme stresses, such as those encountered in earthquake zones. All planning documentation is produced on modern CAD systems; data exchange with other CAD systems is possible via standardized interfaces. By virtue of their active involvement in national and international associations and standardization bodies, our engineers are

1

5

6

Fig. 3: Engineering of high-voltage switchgear

always fully informed of the state of the art, even before a new standard or specification is published. Quality/Environmental Management Our own high-performance, internationally accredited test laboratories and a certified QM system testify to the quality of our products and services. Milestones: ■ 1983: Introduction of a quality system on the basis of Canadian standard CSA Z 299 Level 1 ■ 1989: Certification of the SWH quality system in accordance with DIN EN ISO 9001 by the German Association for Certification of Quality Systems (DQS) ■ 1992: Repetition audit and extension of the quality system to the complete EV H Division ■ 1992: Accreditation of the test laboratories in accordance with DIN EN 45001 by the German Accreditation Body for Technology (DATech) ■ 1994: Certification of the environmentalsystems in accordance with DIN EN ISO 14001 by the DQS ■ 1995: Mutual QEM Certificate

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Know how, experience and worldwide presence A worldwide network of liaison and sales offices, along with the specialist departments in Germany, support and advise our customers in all matters of switchgear technology. Siemens has for many years been a leading supplier of high-voltage equipment, regardless of whether AIS, GIS or GIL has been concerned. For example, outdoor substations of longitudinal in-line design are still known in many countries under the Siemens registered tradename “Kiellinie”. Back in 1968, Siemens supplied the world’s first GIS substation using SF6 as insulating and quenching medium. Gas-insulated transmission lines have featured in the range of products since 1976.

2/3

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Design of Air-Insulated Outdoor Substations

Standards 1

2

3

4

5

6

Air-insulated outdoor substations of open design must not be touched. Therefore, air-insulated switchgear (AIS) is always set up in the form of a fenced-in electrical operating area, to which only authorized persons have access. Relevant IEC 60060 specifications apply to outdoor switchgear equipment. Insulation coordination, including minimum phaseto-phase and phase-to-ground clearances, is effected in accordance with IEC 60071. Outdoor switchgear is directly exposed to the effects of the environment such as the weather. Therefore it has to be designed based on not only electrical but also environmental specifications. Currently there is no international standard covering the setup of air-insulated outdoor substations of open design. Siemens designs AIS in accordance with DIN/VDE standards, in line with national standards or customer specifications. The German standard DIN VDE 0101 (erection of power installations with rated voltages above 1 kV) demonstrates typically the protective measures and stresses that have to be taken into consideration for airinsulated switchgear. Protective measures

7

ker

8

9

10

Protective measures against direct contact, i. e. protection in the form of covering, obstruction or clearance and appropriately positioned protective devices and minimum heights. Protective measures against indirect touching by means of relevant grounding measures in accordance with DIN VDE 0141. Protective measures during work on equipment, i.e. during installation must be planned such that the specifications of DIN EN 50110 (VDE 0105) (e.g. 5 safety rules) are complied with ■ Protective measures during operation, e.g. use of switchgear interlock equipment ■ Protective measures against voltage surges and lightning strike ■ Protective measures against fire, water and, if applicable, noise insulation.

2/4

Stresses ■ Electrical stresses, e.g. rated current, short-circuit current, adequate creepage distances and clearances ■ Mechanical stresses (normal stressing), e.g. weight, static and dynamic loads, ice, wind ■ Mechanical stresses (exceptional stresses), e.g. weight and constant loads in simultaneous combination with maximum switching forces or shortcircuit forces, etc. ■ Special stresses, e.g. caused by installation altitudes of more than 1000 m above sea level, or earthquakes

Variables affecting switchgear installation Switchgear design is significantly influenced by: ■ Minimum clearances (depending on rated voltages) between various active parts and between active parts and earth ■ Arrangement of conductors ■ Rated and short-circuit currents ■ Clarity for operating staff ■ Availability during maintenance work, redundancy ■ Availability of land and topography ■ Type and arrangement of the busbar disconnectors The design of a substation determines its accessibility, availability and clarity. The design must therefore be coordinated in close cooperation with the customer. The following basic principles apply: Accessibility and availability increase with the number of busbars. At the same time, however, clarity decreases. Installations involving single busbars require minimum investment, but they offer only limited flexibility for operation management and maintenance. Designs involving 1 1/2 and 2 circuit-breaker arrangements assure a high redundancy, but they also entail the highest costs. Systems with auxiliary or bypass busbars have proved to be economical. The circuit-breaker of the coupling feeder for the auxiliary bus allows uninterrupted replacement of each feeder circuit-breaker. For busbars and feeder lines, mostly wire conductors and aluminum are used. Multiple conductors are required where currents are high. Owing to the additional shortcircuit forces between the subconductors (pinch effect), however, multiple conductors cause higher mechanical stressing at the tension points. When wire conductors, particularly multiple conductors, are used higher short-circuit currents cause a rise not only in the aforementioned pinch effect but in further force maxima in the event of swinging and dropping of the conductor bundle (cable pull). This in turn results in higher mechanical stresses on the switchgear components. These effects can be calculated in an FEM (Finite Element Method) simulation (Fig. 4).

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Design of Air-Insulated Outdoor Substations

When rated and short-circuit currents are high, aluminum tubes are increasingly used to replace wire conductors for busbars and feeder lines. They can handle rated currents up to 8000 A and short-circuit currents up to 80 kA without difficulty. Not only the availability of land, but also the lie of the land, the accessibility and location of incoming and outgoing overhead lines together with the number of transformers and voltage levels considerably influence the switchgear design as well. A one or two-line arrangement, and possibly a U arrangement, may be the proper solution. Each outdoor switchgear installation, especially for step-up substations in connection with power stations and large transformer substations in the extra-highvoltage transmission system, is therefore unique, depending on the local conditions. HV/MV transformer substations of the distribution system, with repeatedly used equipment and a scheme of one incoming and one outgoing line as well as two transformers together with medium-voltage switchgear and auxiliary equipment, are more subject to a standardized design from the individual power supply companies.

Preferred designs 1

The multitude of conceivable designs include certain preferred versions, which are dependent on the type and arrangement of the busbar disconnectors:

2

H arrangement The H arrangement (Fig. 5) is preferrably used in applications for feeding industrial consumers. Two overhead lines are connected with two transformers and interlinked by a single-bus coupler. Thus each feeder of the switchgear can be maintained without disturbance of the other feeders. This arrangement assures a high availability.

3

4 Special layouts for single busbars up to 145 kV with withdrawable circuit-breaker and modular switchbay arrangement Further to the H arrangement that is built in many variants, there are also designs with withdrawable circuit-breakers and modular switchbays for this voltage range. For detailed information see the following pages:

5

6 Vertical displacement in m

– Q8

– Q8

– Q0

– Q0

–0.6

7

–0.8

M

–1.0 –1.2

– Q1

– Q1

– T5

– T5

– T1

– T1

M

8

–1.4 – T1 –1.6 – Q1 M –1.8 Horizontal displacement in m

–2.0 –2.2 –1.4

–1.0

–0.6

–0.2

0

0.2

0.6

Fig. 4: FEM calculation of deflection of wire conductors in the event of short circuit

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

1.0

1.4

M

– Q10

– T1

M

– Q11

M

– Q0 – F1 = T1

– Q1

9

– Q0 – F1 = T1

Fig. 5: Module plan view

2/5

10

Design of Air-Insulated Outdoor Substations

Withdrawable circuit-breaker

1

2

General For 123/145 kV substations with single busbar system a suitable alternative is the withdrawable circuit-breaker. In this kind of switchgear busbar- and outgoing disconnector become inapplicable (switchgear

without disconnectors). The isolating distance is reached with the moving of the circuit-breaker along the rails, similar to the well-known withdrawable-unit design technique of medium-voltage switchgear. In disconnected position busbar, circuit-breaker and outgoing circuit are separated from each other by a good visible isolating dis-

6300 17001700

2500 2500

3 7600

-Q11-Q12

4

2530 7000

3000 6400

2247 -Q11 -T1/ 1050 -Q12 -Q9 -T5 -Q0 -Q0 -T1 3100 625 7000 625 3100 2500 4500 14450 21450

=T1 -F1 2530 7000

5

6

7 Fig. 6a: H arrangement with withdrawable circuit-breaker, plan view and sections

8

9

tance. An electromechanical motive unit ensures the uninterrupted constant moving motion to both end positions. The circuitbreaker can only be operated if one of the end positions has been reached. Movement with switched-on circuit-breaker is impossible. Incorrect movement, which would be equivalent to operating a disconnector under load, is interlocked. In the event of possible malfunction of the position switch, or of interruptions to travel between disconnected position and operating position, the operation of the circuitbreaker is stopped. The space required for the switchgear is reduced considerably. Due to the arrangement of the instrument transformers on the common steel frame a reduction in the required space up to about 45% in comparison to the conventional switchgear section is achieved. Description A common steel frame forms the base for all components necessary for reliable operation. The withdrawable circuit-breaker contains: ■ Circuit-breaker type 3AP1F ■ Electromechanical motive unit ■ Measuring transformer for protection and measuring purposes ■ Local control cubicle All systems are preassembled as far as possible. Therefore the withdrawable CB can be installed quite easily and efficiently on site. The advantages at a glance ■ Complete system and therefore lower costs for coordination and adaptation. ■ A reduction in required space by about 45% compared with conventional switchbays ■ Clear wiring and cabling arrangement ■ Clear circuit state ■ Use as an indoor switchbay is also possible.

Technical data

10

Fig. 6b: H arrangement with withdrawable circuit-breaker, ISO view

2/6

Nominal voltage [kV]

123 kV (145 kV)

Nominal current [A]

1250 A (2000 A)

Nominal short time current

31.5 kA, 1s, (40 kA, 3s)

[kA]

Auxiliary supply/ motive unit [V]

230/400 V AC

Control voltage

220 V DC

[V]

Fig. 7: Technical data

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Design of Air-Insulated Outdoor Substations

Description A common steel frame forms the base for all components necessary for a reliable operation. The modul contains: ■ Circuit-breaker type 3AP1F ■ Motor-operated disconnecting device ■ Current transformer for protection and measuring purposes ■ Local control cubicle All systems are preassembled as far as possible. Therefore the module can be installed quite easily and efficiently on site.

Modular switchbay

General As an alternative to conventional substations an air-insulated modular switchbay can often be used for common layouts. In this case the functions of several HV devices are combined with each other. This makes it possible to offer a standardized module. Appropriate conventional air-insulated switchbays consist of separately mounted HV devices (for example circuit-breaker, disconnector, earthing switches, transformers), which are connected to each other by conductors/tubes. Every device needs its own foundations, steel structures, earthing connections, primary and secondary terminals (secondary cable routes etc.).

The advantages at a glance ■ Complete system and therefore lower costs for coordination and adaptation. ■ Thanks to the integrated control cubicle, upgrading of the control room is scarecely necessary. ■ A modular switchbay can be inserted very quickly in case of total breakdown or for temporary use during reconstruction. ■ A reduction in required space by about 50% compared with conventional switchbays is achieved by virtue of the compact and tested design of the module (Fig. 8). ■ The application as an indoor switchbay is possible.

1

2

3

4 Technical data

3000

2000 2000

8000

-Q8 -Q0-Q1 -T1 -Q10/-Q11 -T1 -Q1 -Q0 -F1 -T5 3000

4500

4500

7500

3000

=T1

Nominal voltage

123 kV (145 kV)

Nominal current

1250 A (2000 A)

Nominal short current

31.5 kA, 1s, (40 kA, 3s)

Auxiliary supply

230/400 V AC

Control voltage

220 V DC

5

6

Fig. 9: Technical data

4000

11500

7

8

8000 9500

19000

3000

9

A A

9500

10

8000

11500

7500 19000 Fig. 8: Plan view and side view of H arrangement with modular switchbays

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/7

Design of Air-Insulated Outdoor Substations

1

2

3

In-line longitudinal layout, with rotary disconnectors, preferable up to 170 kV The busbar disconnectors are lined up one behind the other and parallel to the longitudinal axis of the busbar. It is preferable to have either wire-type or tubular busbars located at the top of the feeder conductors. Where tubular busbars are used, gantries are required for the outgoing overhead lines only. The system design requires only two conductor levels and is therefore clear. If, in the case of duplicate busbars, the second busbar is arranged in U form relative to the first busbar, it is possible to arrange feeders going out on both sides of the busbar without a third conductor level (Fig. 10).

Dimensions in mm 2500

Section A-A R1 S1 T1 T2 S2 R2

8000 8400 48300

20500

19400 Top view

6500 End bay

9000 4500

A

Normal 9000 bay A

4

Fig. 10: Substation with rotary disconnector, in-line design

5

6

7

Central tower layout with rotary disconnectors, normally only for 245 kV The busbar disconnectors are arranged side by side and parallel to the longitudinal axis of the feeder. Wire-type busbars located at the top are commonly used; tubular busbars are also conceivable. This arrangement enables the conductors to be easliy jumpered over the circuit-breakers and the bay width to be made smaller than that of in-line designs. With three conductor levels the system is relatively clear, but the cost of the gantries is high (Fig. 11).

Dimensions in mm 3000 12500 9000 7000

18000

17000

17000

16000

8 Fig.11: Central tower design

Diagonal layout with pantograph disconnectors, preferable up to 245 kV

9

10

The pantograph disconnectors are placed diagonally to the axis of the busbars and feeder. This results in a very clear, spacesaving arrangement. Wire and tubular conductors are customary. The busbars can be located above or below the feeder conductors (Fig. 12).

Section

Dimensions in mm Bypass bus

Bus system 13300 10000 8000

28000

48000

10000

10400 Top view 5000 18000 4000 4000 5000

Fig. 12: Busbar area with pantograph disconnector of diagonal design, rated voltage 420 kV

2/8

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Design of Air-Insulated Outdoor Substations

1 1/2 circuit-breaker layout, preferable up to 245 kV

Planning principles 1

The 1 1/2 circuit-breaker arrangement assures high supply reliability; however, expenditure for equipment is high as well. The busbar disconnectors are of the pantograph, rotary and vertical-break type. Vertical-break disconnectors are preferred for the feeders. The busbars located at the top can be of wire or tubular type. Of advantage are the equipment connections, which are very short and enable (even in the case of multiple conductors) high short-circuit currents to be mastered. Two arrangements are customary: ■ External busbar, feeders in line with three conductor levels ■ Internal busbar, feeders in H arrangement with two conductor levels (Fig. 13).

For air-insulated outdoor substations of open design, the following planning principles must be taken into account: ■ High reliability – Reliable mastering of normal and exceptional stresses – Protection against surges and lightning strikes – Protection against surges directly on the equipment concerned (e.g. transformer, HV cable)

2

3

■ Good clarity and accessibility

Dimensions in mm 4000

17500

– Clear conductor routing with few conductor levels – Free accessibility to all areas (no equipment located at inaccessible depth) – Adequate protective clearances for installation, maintenance and transportation work – Adequately dimensioned transport routes

4

5

■ Positive incorporation into surroundings

8500

48000

29000

– As few overhead conductors as possible – Tubular instead of wire-type busbars – Unobtrusive steel structures – Minimal noise and disturbance level

6

■ EMC grounding system

18000

for modern control and protection

7

■ Fire precautions and environmental

Fig.13 : 1 1/2 Circuit-breaker design

protection – Adherence to fire protection specifications and use of flame-retardant and nonflammable materials – Use of environmentally compatible technology and products

8

For further information please contact: Fax: ++ 49 - 9131- 73 18 58 e-mail: [email protected]

9

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/9

Circuit-Breakers for 72 kV up to 800 kV

General 1

2

3

4

5

Circuit-breaker for air-insulated switchgear Circuit-breakers are the main module of both AIS and GIS switchgear. They have to meet high requirements in terms of: ■ Reliable opening and closing ■ Consistent quenching performance with rated and short-circuit currents even after many switching operations ■ High-performance, reliable maintenancefree operating mechanisms. Technology reflecting the latest state of the art and years of operating experience are put to use in constant further development and optimization of Siemens circuitbreakers. This makes Siemens circuitbreakers able to meet all the demands placed on high-voltage switchgear. The comprehensive quality system, ISO 9001 certified, covers development, manufacture, sales, installation and aftersales service. Test laboratories are accredited to EN 45001 and PEHLA/STL.

Main construction elements 6

7

8

9

Each circuit-breaker bay for gas-insulated switchgear includes the full complement of isolator switches, grounding switches (regular or proven), instrument transformers, control and protection equipment, interlocking and monitoring facilities commonly used for this type of installation (See chapter GIS, page 2/30 and following). Circuit-breakers for air-insulated switchgear are individual components and are assembled together with all individual electrical and mechanical components of an AIS installation on site. All Siemens circuit-breaker types, whether air or gas-insulated, are made up of the same range of components, i.e.: ■ Interrupter unit ■ Operating mechanism ■ Sealing system ■ Operating rod ■ Control elements.

Control elements

Operating mechanism

Interrupter unit

10

Circuit-breaker in SF6-insulated switchgear Fig. 14: Circuit-breaker parts

2/10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Circuit-Breakers for 72 kV up to 800 kV

Interrupter unit – two arc-quenching principles The Siemens product range includes highvoltage circuit-breakers with self-compression interrupter chambers and twin-nozzle interrupter chambers – for optimum switching performance under every operating condition for every voltage level. Self-compression breakers 3AP high-voltage circuit-breakers for the lower voltage range ensure optimum use of the thermal energy of the arc in the contact tube. This is achieved by the selfcompression switching unit. Siemens patented this arc-quenching principle in 1973. Since then, we have continued to develop the technology of the selfcompression interrupter chamber. One of the technical innovations is that the arc energy is being increasingly used to quench the arc. In short-circuit breaking operations the actuating energy required is reduced to that needed for mechanical contact movement. That means the operating energy is truly minimized. The result is that the selfcompression interrupter chamber allows the use of a compact stored-energy spring mechanism with unrestrictedly high dependability. Twin-nozzle breakers On the 3AQ and 3AT switching devices, a contact system with graphite twin-nozzles ensures consistent arc-quenching behavior and constant electric strength, irrespective of pre-stressing, i.e. the number of breaks and the switched current. The graphite twin-nozzles are resistant to burning and thus have a very long service life. As a consequence, the interrupter unit of the twin-nozzle breaker is particularly powerful. Moreover, this type of interrupter chamber offers other essential advantages. Generally, twin-nozzle interrupter chambers operate with low overpressures during arcquenching. Minimal actuating energy is adequate in this operating system as well. The resulting arc plasma has a comparatively low conductivity, and the switching capacity is additionally favourably influenced as a result.

The twin-nozzle system has also proven itself in special applications. Its specific properties support switching without restriking of small inductive and capacitive currents. By virtue of its high arc resistance, the twin-nozzle system is particularly suitable for breaking certain types of short circuit (e.g. short circuits close to generator terminals) on account of its high arc resistance.

Specific use of the electrohydraulic mechanism

Operating mechanism – two principles for all specific requirements

Advantages of the electrohydraulic mechanism at a glance:

The operating mechanism is a central module of the high-voltage circuit-breakers. Two different mechanism types are available for Siemens circuit-breakers: ■ Stored-energy spring actuated mechanism, ■ Electrohydraulic mechanism, depending on the area of application and voltage level, thus every time ensuring the best system of actuation. The advantages are trouble-free, economical and reliable circuit-breaker operation for all specific requirements. Specific use of the stored-energy spring mechanism The actuation concept of the 3AP high-voltage circuit-breaker is based on the storedenergy spring principle. The use of such an operating mechanism in the lower voltage range became appropriate as a result of development of a self-compression interrupter chamber that requires only minimal actuation energy.

The actuating energy required for the 3AQ and 3AT high-voltage circuit-breakers at higher voltage levels is provided by proven electrohydraulic mechanisms. The interrupter chambers of these switching devices are based on the graphite twin-nozzle system.

■ Electrohydraulic mechanisms provide the

high actuating energy that makes it possible to have reliable control even over very high switching capacities and to be in full command of very high loads in the shortest switching time. ■ The switch positions are held safely even in the event of an auxiliary power failure. ■ A number of autoreclosing operations are possible without the need for recharging. ■ Energy reserves can be reliably controlled at any time. ■ Electrohydraulic mechanisms are maintenance-free, economical and have a long service life. ■ They satisfy the most stringent requirements regarding environmental safety. This has been proven by electrohydraulic mechanisms in Siemens high-voltage circuit-breakers over many years of service.

1

2

3

4

5

6

7

8

Advantages of the stored-energy spring mechanism at a glance:

9

■ The stored-energy spring mechanism of-

fers the highest degree of operational safety. It is of simple and sturdy design – with few moving parts. Due to the self-compression principle of the interrupter chamber, only low actuating forces are required. ■ Stored-energy spring mechanisms are readily available and have a long service life: Minimal stressing of the latch mechanisms and rolling-contact bearings in the operating mechanism ensure reliable and wear-free transmission of forces. ■ Stored-energy spring mechanisms are maintenance-free: the spring charging gear is fitted with wear-free spur gears, enabling load-free decoupling.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

10

2/11

Circuit-Breakers for 72 kV up to 245 kV

1

2

Siemens circuit-breakers for the lower voltage levels 72 kV up to 245 kV, whether for air-insulated or gas-insulated switchgear, are equipped with self-compression switching units and spring-stored energy operating mechanisms.

The interrupter unit Self-compression system

3

4

The current path is formed by the terminal plates (1) and (8), the contact support (2), the base (7) and the moving contact cylinder (6). In closed state the operating current flows through the main contact (4). An arcing contact (5) acts parallel to this.

Closed position

6

7

1 2 3 4 5

8 6

Major features:

During the opening process, the main contact (4) opens first and the current commutates on the still closed arcing contact. If this contact is subsequently opened, an arc is drawn between the contacts (5). At the same time, the contact cylinder (6) moves into the base (7) and compresses the quenching gas there. The gas then flows in the reverse direction through the contact cylinder (6) towards the arcing contact (5) and quenches the arc there.

■ ■ ■ ■

Self-compression interrupter chamber Use of the thermal energy of the arc Minimized energy consumption High reliability for a long time

Breaking fault currents

The current path

5

Breaking operating currents

In the event of high short-circuit currents, the quenching gas on the arcing contact is heated substantially by the energy of the arc. This leads to a rise in pressure in the contact cylinder. In this case the energy for creation of the required quenching pressure does not have to be produced by the operating mechanism. Subsequently, the fixed arcing contact releases the outflow through the nozzle (3). The gas flows out of the contact cylinder back into the nozzle and quenches the arc.

Opening Main contact open

Opening Arcing contact open

Open position

1 2 3 4 5 6

Terminal plate Contact support Nozzle Main contact Arc contact Contact cylinder 7 Base 8 Terminal plate

9 7

10

8

Fig. 15: The interrupter unit

2/12

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Circuit-Breakers for 72 kV up to 245 kV

The operating mechanism 1 2 3 4 5 6 7

Spring-stored energy type Siemens circuit-breakers for voltages up to 245 kV are equipped with spring-stored energy operating mechanisms. These drives are based on the same principle that has been proving its worth in Siemens low and medium-voltage circuit-breakers for decades. The design is simple and robust with few moving parts and a vibration-isolated latch system of highest reliability. All components of the operating mechanism, the control and monitoring equipment and all terminal blocks are arranged compact and yet clear in one cabinet. Depending on the design of the operating mechanism, the energy required for switching is provided by individual compression springs (i.e. one per pole) or by springs that function jointly on a triple-pole basis. The principle of the operating mechanism with charging gear and latching is identical on all types. The differences between mechanism types are in the number, size and arrangement of the opening and closing springs.

1

2

10

8 9 10 11 12 13 14 15 16

6

11

17 18

7

12 13

3 9

4 5

Corner gears Coupling linkage Operating rod Closing release Cam plate Charging shaft Closing spring connecting rod Closing spring Hand-wound mechanism Charging mechanism Roller level Closing damper Operating shaft Opening damper Opening release Opening spring connecting rod Mechanism housing Opening spring

■ ■

3

4

5

14

■ Uncomplicated, robust construction ■ ■ ■

2

6

Major features at a glance with few moving parts Maintenance-free Vibration-isolated latches Load-free uncoupling of charging mechanism Ease of access 10,000 operating cycles

1

15 16

7

17 8 18

8 Fig. 16

9

10

Fig. 17: Combined operating mechanism and monitoring cabinet

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/13

Circuit-Breakers for 245 kV up to 800 kV

1

Siemens circuit-breakers for the higher voltage levels 245 kV up to 800 kV, whether for air-insulated or gas-insulated switchgear, are equipped with twin-nozzle interrupter chambers and electrohydraulic operating mechanisms.

2 The interrupter unit 3

4

Twin-nozzle system Current path assembly The conducting path is made up of the terminal plates (1 and 7), the fixed tubes (2) and the spring-loaded contact fingers arranged in a ring in the moving contact tube (3).

5

6

7

Breaker in closed position

Arc-quenching assembly

Major features

The fixed tubes (2) are connected by the contact tube (3) when the breaker is closed. The contact tube (3) is rigidly coupled to the blast cylinder (4), the two together with a fixed annular piston (5) in between forming the moving part of the break chamber. The moving part is driven by an operating rod (8) to the effect that the SF6 pressure between the piston (5) and the blast cylinder (4) increases. When the contacts separate, the moving contact tube (3), which acts as a shutoff valve, releases the SF6. An arc is drawn between one nozzle (6) and the contact tube (3). It is driven in a matter of milliseconds between the nozzles (6) by the gas jet and its own electrodynamic forces and is safely extinguished. The blast cylinder (4) encloses the arcquenching arrangement like a pressure chamber. The compressed SF6 flows radially into the break by the shortest route and is discharged axially through the nozzles (6). After arc extinction, the contact tube (3) moves into the open position. In the final position, handling of test voltages in accordance with IEC 60000 and ANSI is fully assured, even after a number of short-circuit switching operations.

■ Erosion-resistant graphite nozzles ■ Consistently high dielectric strength ■ Consistent quenching capability across

Precompression

Gas flow during arc quenching

the entire performance range ■ High number of short-circuit breaking

operations ■ High levels of availability ■ Long maintenance intervals.

Breaker in open position

1 1 Upper terminal

8

plate

2 3 6

9

4 5 2

10

8

2 Fixed tubes 3 Moving contact tube Arc

4 Blast cylinder 5 Blast piston 6 Arc-quenching nozzles

7 Lower terminal plate

8 Operating rod

7

Fig. 18: The interrupter unit

2/14

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Circuit-Breakers for 245 kV up to 800 kV

The operating mechanism Electrohydraulic type All hydraulically operated Siemens circuitbreakers have a uniform operating mechanism concept. Identical operating mechanisms (modules) are used for single or triple-pole switching of outdoor circuitbreakers. The electrohydraulic operating mechanisms have proved their worth all over the world. The power reserves are ample, the switching speed is high and the storage capacity substantial. The working capacity is indicated by the permanent self-monitoring system. The force required to move the piston and piston rod is provided by differential oil pressure inside a sealed system. A hydraulic storage cylinder filled with compressed nitrogen provides the necessary energy. Electromagnetic valves control the oil flow between the high and low-pressure side in the form of a closed circuit.

■ Tripping:

The hydraulic valve is changed over electromagnetically, thus relieving the larger piston surface of pressure and causing the piston to move onto the OFF position. The breaker is ready for instant operation because the smaller piston surface is under constant pressure. Two electrically separate tripping circuits are available for changing the valve over for tripping.

1

2

3

4

5

Main features: ■ Plenty of operating energy ■ Long switching sequences ■ Reliable check of energy reserves ■

■ ■ ■ ■

at any time Switching positions are reliably maintained, even when the auxiliary supply fails Excessive strong foundations Low-noise switching No oil leakage and consequently environmentally compatible Maintenance-free.

6

Fig. 19: Operating unit of the Q range AIS circuit breakers

Monitoring unit and hydraulic pump with motor

Description of function

Fig. 20: Operating cylinder with valve block and magnetic releases

P

P

7

P

P

8

Oil tank

■ Closing:

The hydraulic valve is opened by electromagnetic means. Pressure from the hydraulic storage cylinder is thereby applied to the piston with two different surface areas. The breaker is closed via couplers and operating rods moved by the force which acts on the larger surface of the piston. The operating mechanism is designed to ensure that, in the event of a pressure loss, the breaker remains in the particular position.

Hydraulic storage cylinder

M

M

9

N2

Operating cylinder

10 Operating piston Main valve

Auxiliary switch

Pilot control Releases

On

Off

Fig. 21: Schematic diagram of a Q-range operating mechanism

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/15

Live-Tank Circuit-Breakers for 72 kV up to 800 kV

1

Circuit-breakers for air-insulated switchgear Standard live-tank breakers The construction

2

3

4

5

6

7

All live-tank circuit-breakers are of the same general design, as shown in the illustrations. They consist of the following main components: 1) Interrupter unit 2) Closing resistor (if applicable) 3) Operating mechanism 4) Insulator column (AIS) 5) Operating rod 6) Breaker base 7) Control unit The uncomplicated design of the breakers and the use of many similar components, such as interrupter units, operating rods and control cabinets, ensure high reliability because the experience of many breakers in service has been applied in improvement of the design. The twin nozzle interrupter unit for example has proven its reliability in more than 60,000 units all over the world. The control unit includes all necessary devices for circuit-breaker control and monitoring, such as: ■ Pressure/SF6 density monitors ■ Gauges for SF6 and hydraulic pressure (if applicable) ■ Relays for alarms and lockout ■ Antipumping devices ■ Operation counters (upon request) ■ Local breaker control (upon request) ■ Anticondensation heaters.

Fig. 22: 145 kV circuit-breaker 3AP1FG with triple-pole spring stored-energy operating mechanism

Fig. 23: 800 kV circuit-breaker 3AT5

8

9

Transport, installation and commissioning are performed with expertise and efficiency. The tested circuit-breaker is shipped in the form of a small number of compact units. If desired, Siemens can provide appropriately qualified personnel for installation and commissioning.

10

Fig. 24: 245 kV circuit-breaker 3AQ2

2/16

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Live-Tank Circuit-Breakers for 72 kV up to 800 kV

1 1

1

7

2

3

5 6

2

2 8

5

3

1 2 3 4

Interrupter unit Closing resistor Valve unit Electrohydraulic operating mechanism 5 Insulator columns 6 Breaker base 7 Control unit

9 13 12

4

10 11 4

5

3 4 7 6 Fig. 25: Type 3AT4/5

1

1 2 3 4 5 6 7 8 9 10 11 12 13

Interrupter unit Arc-quenching nozzles Moving contact Filter Blast piston Blast cylinder Bell-crank mechanism Insulator column Operating rod Hydraulic operating mechanism ON/OFF indicator Oil tank Control unit

6

7

8

Fig. 27: Type 3AQ2

9

2

10

3 5 4

1 2 3 4

Interrupter unit

Post insulator Circuit-breaker base Operating mechanism and control cubicle

5 Pillar Fig. 26: Type 3AP1FG

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/17

Live-Tank Circuit-Breakers for 72 kV up to 800 kV

1

Technical data

2

3

4

5

6

7

8

9

10

Type Rated voltage Number of interrupter units per pole Rated power-frequency withstand voltage 1 min. Rated lightning impulse withstand voltage 1.2 / 50 µs Rated switching impulse withstand voltage Rated current up to Rated short-time current (3 s) up to Rated peak withstand current up to Rated short-circuit-breaking current up to Rated short-circuit making current up to Rated duty cycle Break time Frequency Operating mechanism type Control voltage Motor voltage Design data of the basic version: Clearance Phase/earth in air across the contact gap Minimum creepage Phase/earth distance across the contact gap Dimensions Height Width Depth Distance between pole centers Weight of circuit-breaker Inspection after

3AP1/3AQ1

3AP2/3AQ2

72.5

123

145

170

245/300

362

1

1

1

1

1

2

2

[kV]

140

230

275

325

460

520

610

[kV]

325

550

650

750

1050

1175

1425

[kV]

–

–

–

–

–/850

950

1050

[A] [kA] [kA] [kA]

4000

4000

4000

4000

4000

4000

4000

40

40

40

40/50

50

63

63

108

108

108

135

135

170

170

40

40

40

40/50

50

63

63

[kA]

108

108

108

135

135

170

170

3

3

3

3

3

3

3

50/60

50/60

50/60

50/60

50/60

[kV]

O - 0.3 s - CO - 3 min - CO

[cycles] [Hz]

50/60 50/60

or

420

CO - 15 s - CO

Spring-stored energy mechanism/Electrohydraulic mechanism

[V, DC] [V, DC] [V, DC]

60…250 60…250 120…240, 50/60 Hz

[mm] [mm] [mm] [mm]

700 1200

1250 1200

1250 1200

1500 1400

2200 1900/2200

2750 2700

3400 3200

2248 3625

3625 3625

3625 3625

4250 4250

6150/7626 6125/7500

7875 9050

10375 10500

[mm] [mm] [mm] [mm] [kg]

2750 3200 660 1350

3300 3900 660 1700

3300 3900 660 1700

4030 4200 660 1850

5220/5520 6600/7000 800 2800/3000

4150 8800 3500 3800

4800 9400 4100 4100

1350

1500

1500

1600

3000

4700

5000

25 years

Fig. 28a

2/18

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Live-Tank Circuit-Breakers for 72 kV up to 800 kV

1

2

3

3AT2/3AT3*

4

3AT4/3AT5*

245

300

362

420

550

362

420

550

2

2

2

2

2

4

4

4

800 4

460

460

520

610

800

520

610

800

1150

1050

1050

1175

1425

1550

1175

1425

1550

2100

–

850

950

1050

1175

950

1050

1175

1425

4000

4000

4000

4000

4000

4000

4000

4000

4000

6

80

63

63

63

63

80

80

63

63

216

170

170

170

170

200

200

160

160

80

63

63

63

63

80

80

63

63

216

170

170

170

170

200

200

160

160

2

2

2

O - 0.3 s - CO - 3 min - CO 50/60

50/60

50/60

2 50/60

5

or

7

CO - 15 s - CO

2

2

2

2

2

50/60

50/60

50/60

50/60

50/60

8

Electrohydraulic mechanism 48…250 48…250 or 208/120…500/289 50/60 Hz

9

2200 2000

2200 2400

2700 2700

3300 3200

3800 3800

2700 4000

3300 4000

3800 4800

5000 6400

6050 6070

6050 8568

7165 9360

9075 11390

13750 13750

7165 12140

9075 12140

10190 17136

13860 22780

4490 7340 4060 3000

4490 8010 4025 3400

6000 9300 4280 3900

6000 10100 4280 4300

6700 13690 5135 5100

4990 10600 6830 4350

6000 11400 6830 4750

6550 16600 7505 7200

8400 22200 9060 10000

5980

6430

9090

8600

12500

14400

14700

19200

23400

10

25 years Fig. 28b Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

* with closing resistor

2/19

Dead-Tank Circuit-Breakers for 72 kV up to 245 kV

1

Circuit-breakers in dead-tank design

2

For certain substation designs, dead-tank circuit-breakers might be required instead of the standard live-tank breakers. For these purposes Siemens can offer the dead-tank circuit breaker types.

Main features at a glance 3 Reliable opening and closing ■ Proven contact and arc-quenching

system

4

5

■ Consistent quenching performance

with rated and short-circuit currents even after many switching operations ■ Similar uncomplicated design for all voltages High-performance, reliable operating mechanisms ■ Easy-to-actuate spring operating

mechanisms ■ Hydraulic operating mechanisms with

6

on-line monitoring Economy

Fig. 29a: SPS-2 circuit-breaker 72.5 kV

■ Perfect finish ■ Simplified, quick installation process

7

■ Long maintenance intervals ■ High number of operating cycles ■ Long service life

Individual service

8

■ Close proximity to the customer ■ Order specific documentation ■ Solutions tailored to specific problems ■ After-sales service available promptly

worldwide

9

The right qualifications ■ Expertise in all power supply matters ■ 30 years of experience with SF6-insulat-

ed circuit breakers

10

■ A quality system certified to ISO 9001,

covering development, manufacture, sales, installation and after-sales service ■ Test laboratories accredited to EN 45001 and PEHLA/STL

Fig. 29b: SPS-2 circuit-breaker 170 kV

2/20

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Dead-Tank Circuit-Breakers for 72 kV up to 245 kV

Subtransmission breaker Type SPS-2 and 3AP1-DT Type SPS-2 power circuit-breakers (Fig. 29a/b) are designed as general, definite-purpose breakers for use at maximum rated voltages of 72.5 and 245 kV. The construction The type SPS-2 breaker consists of three identical pole units mounted on a common support frame. The opening and closing force of the FA2/4 spring operating mechanism is transferred to the moving contacts of the interrupter through a system of connecting rods and a rotating seal at the side of each phase. The tanks and the porcelain bushings are charged with SF6 gas at a nominal pressure of 6.0 bar. The SF6 serves as both insulation and arc-quenching medium. A control cabinet mounted at one end of the breaker houses the spring operating mechanism and breaker control components. Interrupters are located in the aluminum housings of each pole unit. The interrupters use the latest Siemens puffer arcquenching system. The spring operating mechanism is the same design as used with the Siemens 3AP breakers. This design has been in service for years, and has a well documented reliability record. Customers can specify up to four (in some cases, up to six) bushing-type current transformers (CT) per phase. These CTs, mounted externally on the aluminum housings, can be removed without disturbing the bushings.

Operating mechanism

Included in the control cabinet are necessary auxiliary switches, cutoff switch, latch check switch, alarm switch and operation counter. The control relays and three control knife switches (one each for the control, heater and motor) are mounted on a control panel. Terminal blocks on the side and rear of the housing are available for control and transformer wiring. For non US markets the control cabinet is also available similar to the 3AP cabinet (3AP1-DT).

The type FA2/4 mechanically and electrically trip-free spring mechanism is used on type SPS-2 breakers. The type FA2/4 closing and opening springs hold a charge for storing ”open-close-open“ operations A weatherproof control cabinet has a large door, sealed with rubber gaskets, for easy access during inspection and maintenance. Condensation is prevented by units offering continuous inside/outside temperature differential and by ventilation.

1

2

3

4

Technical data

5

6

7 Type

SPS-2/3AP1-DT

Rated voltage

[kV]

38

48.3

72.5

121

145

169

242

Rated power-frequency withstand voltage

[kV]

80

105

160

260

310

365

425

Rated lighting impulse withstand voltage

[kV]

200

250

350

550

650

750

900/1050

Rated switching impulse withstand voltage

[kV]

–

–

–

–

–

–

–/850

4000

4000

4000

4000

4000

4000

40

40

63

63

63

63

Rated nominal current up to

9 [A] 4000

Rated breaking current up to [kA] Operating mechanism type

40

Spring-stored-energy mechanism

Fig. 30

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

8

2/21

10

Dead-Tank Circuit-Breakers for 550 kV

1

Circuit-breaker Type 3AT2/3-DT Composite insulators

2

3

4

5

6

7

8

The 3AT2/3-DT is available with bushings made from composite insulators – this has many practical advantages. The SIMOTEC® composite insulators manufactured by Siemens consist of a basic body made of epoxy resin reinforced glass fibre tubes. The external tube surface is coated with vulcanized silicon. As is the case with porcelain insulators, the external shape of the insulator has a multished profile. Field grading is implemented by means of a specially shaped screening electrode in the lower part of the composite insulator. The bushings and the metal tank of the circuit-breaker surround a common gas volume. The composite insulator used on the bushing of the 3AT2/3-DT is a onepiece insulating unit. Compared with conventional housings, composite insulators offer a wide range of advantages in terms of economy, efficiency and safety.

Hydraulic drive

For further information please contact:

The operating energy required for the 3AT2/3-DT interrupters is provided by the hydraulic drive, which is manufactured inhouse by Siemens. The functional principle of the hydraulic drive constitutes a technically clear solution which offers certain fundamental advantages. Hydraulic drives provide high amounts of energy economically and reliably. In this way, even the most demanding switching requirements can be mastered in short opening times. Siemens hydraulic drives are maintenancefree and have a particulary long operating life. They meet the strictest criteria for enviromental acceptability. In this respect, too, Siemens hydraulic drives have proven themselves throughout years of operation.

Fax: ++ 49 - 3 03 86 - 2 58 67

Technical data

Interrupter unit The 3AT2/3-DT pole consists of two breaking units in series impressive in the sheer simplicity of their design. The proven Siemens contact system with double graphite nozzles assures faultless operation, consistently high arc-quenching capacity and a long operating life, even at high switching frequencies. Thanks to constant further development, optimization and consistent quality assurance, Siemens arc-quencing systems meet all the requirements placed on modern high-voltage technology.

9

10

Type

3AT 2/3-DT

Rated voltage

[kV]

550

Rated power-frequency withstand voltage

[kV]

860

Rated lighting impulse withstand voltage

[kV]

1800

Rated switching impulse withstand voltage

[kV]

1300

Rated nominal current up to

[A]

4000

Rated breaking current up to

[kA]

50/63

Operating mechanism type

Electrohydraulic mechanism

Fig. 31

2/22

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Dead-Tank Circuit-Breakers for 550 kV

1

2

3

4

5

6

7

8

9 Fig. 32: The 3AT2/3-DT circuit-breaker with SIMOTEC composite insulator bushings

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/23

Surge Arresters

Nonlinear resistors

Introduction 1

2

3

4

5

The main task of an arrester is to protect equipment from the effects of overvoltages. During normal operation, it should have no negative effect on the power system. Moreover, the arrester must be able to withstand typical surges without incurring any damage. Nonlinear resistors with the following properties fulfill these requirements: ■ Low resistance during surges so that overvoltages are limited ■ High resistance during normal operation, so as to avoid negative effects on the power system and ■ Sufficient energy absorption capability for stable operation With this kind of nonlinear resistor, there is only a small flow of current when continuous operating voltage is being applied. When there are surges, however, excess energy can be quickly removed from the power system by a high discharge current.

6

7

8

Nonlinear resistors, comprising metal oxide (MO), have proved especially suitable for this. The nonlinearity of MO resistors is considerably high. For this reason, MO arresters, as the arresters with MO resistors are known today, do not need series gaps. Siemens has many years of experience with arresters – with the previous gapped SiC-arresters and the new gapless MO arresters – in low-voltage systems, distribution systems and transmission systems. They are usually used for protecting transformers, generators, motors, capacitors, traction vehicles, cables and substations. There are special applications such as the protection of ■ Equipment in areas subject to earthquakes or heavy pollution ■ Surge-sensitive motors and dry-type transformers ■ Generators in power stations with arresters which posses a high degree of short-circuit current strength ■ Gas-insulated high-voltage metalenclosed switchgear (GIS) ■ Thyristors in HVDC transmission installations ■ Static compensators ■ Airport lighting systems ■ Electric smelting furnaces in the glass and metals industries ■ High-voltage cable sheaths ■ Test laboratory apparatus.

MO arresters are used in medium, high and extra-high-voltage power systems. Here, the very low protection level and the high energy absorption capability provided during switching surges are especially important. For high voltage levels, the simple construction of MO arresters is always an advantage. Another very important advantage of MO arresters is their high degree of reliability when used in areas with a problematic climate, for example in coastal and desert areas, or regions affected by heavy industrial air pollution. Furthermore, some special applications have become possible only with the introduction of MO arresters. One instance is the protection of capacitor banks in series reactive-power compensation equipment which requires extremly high energy absorption capabilities. Arresters with polymer housings Fig. 34 shows two Siemens MO arresters with different types of housing. In addition to what has been usual up to now – the porcelain housing – Siemens offers also the latest generation of high-voltage surge arresters with polymer housing.

Rated voltage ÛR

Arrester voltage referred to continuous operating voltage Û/ÛC

Continuous operating voltage ÛC

2

9

10

1 20 °C

Fig. 34: Measurement of residual voltage on porcelain-housed (foreground) and polymer-housed (background) arresters

115 °C 150 °C

0

10-4

10-3

10-2

10-1

1

10

102

103

104

Current through arrester Ia [A] Fig. 33: Current/voltage characteristics of a non-linear MO arrester

2/24

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Surge Arresters

Fig. 35 shows the sectional view of such an arrester. The housing consists of a fiberglass-reinforced plastic tube with insulating sheds made of silicon rubber. The advantages of this design which has the same pressure relief device as an arrester with porcelain housing are absolutely safe and reliable pressure relief characteristics, high mechanical strength even after pressure relief and excellent pollution-resistant properties. The very good mechanical features mean that Siemens arresters with polymer housing (type 3EQ/R) can serve as post insulators as well. The pollution-resistant properties are the result of the water-repellent effect (hydrophobicity) of the silicon rubber, which even transfers its effects to pollution.

The polymer-housed high-voltage arrester design chosen by Siemens and the highquality materials used by Siemens provide a whole series of advantages including long life and suitability for outdoor use, high mechanical stability and ease of disposal. Another important design shown in Fig. 36 are the gas-insulated metal-enclosed surge arresters (GIS arresters) which have been made by Siemens for more then 25 years. There are two reasons why, when GIS arresters are used with gas-insulated switchgear, they usually offer a higher protective safety margin than when outdoor-type arresters are used (see also IEC 60099-5, 1996-02, Section 4.3.2.2.): Firstly, they can be installed closer to the item to be protected so that traveling wave effects can

be limited more effectively. Secondly, compared with the outdoor type, inductance of the installation is lower (both that of the connecting conductors and that of the arrester itself). This means that the protection offered by GIS arresters is much better than by any other method, especially in the case of surges with a very steep rate of rise or high frequency, to which gas-insulated switchgear is exceptionally sensitive. Please find an overview of the complete range of Siemens arresters in Figs. 37 and 38, pages 26 and 27.

1

2

3

For further information please contact: Fax: ++ 49 - 3 03 86 -2 67 21 e-mail: [email protected]

4

SF6-SF6 bushing (SF6 -Oil bushing on request)

5

Flange with gas diverter nozzle Seal

Access cover with pressure relief device and filter

6

Pressure relief diaphragm Compressing spring

Spring contact

Metal oxide resistors

Grading hood

Composite polymer housing FRP tube/silicon sheds

Metal-oxide resistors

7

8

Supporting rods Enclosure

9

10 Fig. 36: Gas-insulated metal-enclosed arrester (GIS arrester)

Fig. 35: Cross-section of a polymer-housed arrester

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/25

Low-Voltage and Medium-Voltage Arresters and Limiters (230/400 V to 52 kV)

Type

Low-voltage arresters and limiters

1

3EA2

3EF1 3EF2 3EF3 3EF4 3EF5

3EC3

3EE2

3EH2

3EG5

3EK5

3EK7

3EQ1-B

Applications

Lowvoltage overhead line systems

Motors, dry-type transformers, airfield lighting systems, sheath voltage limiters, protection of converters for drives

DC systems (locomotives, overhead contact lines)

Generators, motors, melting furnaces, 6-arrester connections, power plants

Distribution systems metalenclosed gas-insulated switchgear with plug-in connection

Distribution systems and mediumvoltage switchgear

Distribution systems and mediumvoltage switchgear

Distribution systems and mediumvoltage switchgear

AC and DC locomotives, overhead contact lines

Nom. syst. [kV] voltage (max.)

1

10

3

30

45

30

60

30

25

12

4

36

52

36

72.5

36

30

2

3

4

5

Highest [kV] voltage for equipment (max.)

6

Medium-voltage arresters

Maximum rated voltage

[kV]

1

15

4

45

52

45

75

45

37 (AC) 4 (DC)

Nominal discharge current

[kA]

5

1

10

10

10

10

10

10

10

Maximum [kJ/kV] energy absorbing capability (at thermal stability)

–

3EF1/2 3EF3 3EF4 3EF5

0.8 9 12.5 8

10

10

1.3

3

5

3

10

[A]

1 x 380 20 x 250

3EF4 3EF5

1500 1200

1200

1200

200

300

500

300

1200

9

Maximum long duration current impulse, 2 ms

[kA]

Line disconnection

40

40

300

16

20

20

20

40

10

Maximum shortcircuit rating

Porcelain

Porcelain

Metal

Porcelain

Porcelain

Polymer

Polymer

7

8

Housing material

Polymer

Polymer

Fig. 37: Low and medium-voltage arresters

2/26

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

High-Voltage Arresters (72.5 to 800 kV)

Type

Applications

Nom. syst. voltage (max.)

[kV]

3EP1

3EP4

3EP2

3EP3

3EQ1

Mediumand highvoltage systems, outdoor installations

Mediumand highvoltage systems, outdoor installations

Highvoltage systems, outdoor installations

Highvoltage systems, outdoor installations, HVDC, SC & SVC applications

Mediumand highvoltage systems, outdoor installations

Metal-oxide surge arresters 3EQ4 3EQ3 3EP2-K 3ER3 Highvoltage systems, outdoor installations

3EP3-K Highvoltage systems, metalenclosed gasinsulated switchgear

Highvoltage systems, outdoor installations, HVDC, SC & SVC applications

Highvoltage systems, metalenclosed gasinsulated switchgear

Highvoltage systems, metalenclosed gasinsulated switchgear

60

150

500

765

275

500

765

150

150

500

Highest [kV] voltage for equip. (max.)

72.5

170

550

800

300

550

800

170

170

550

Maximum rated voltage

[kV]

84

147

468

612

240

468

612

180

180

444

Nominal discharge current

[kA]

2

3

4

5 10

10

10/20

10/20

10

10/20

20

10/20

10/20

20

Maximum line discharge class

2

3

5

5

3

5

5

4

4

5

Maximum [kJ/kV] energy absorbing capability (at thermal stability)

5

8

12.5

20

8

12.5

20

10

10

12.5

Maximum long duration current impulse, 2 ms

[A]

500

Maximum shortcircuit rating

[kA]

40

2.12)

Minimum [kNm]2) breaking moment

Housing material

6

7

1500

3900

850

1500

3900

1200

1200

1500

8

65

65

100

50

65

80

–

–

–

9

4.52)

12.52)

342)

850

10 63)

Maximum [MPSL] permissible service load

1)

1

3EP2-K3

Porcelain Porcelain

Silicon rubber sheds

2) Acc.

to DIN 48113

Porcelain Porcelain 3)

213)

723)

Polymer1) Polymer1) Polymer1)

–

Metal

–

–

Metal

Metal

Acc. to IEC TC 37 WG5 03.99; > 50% of this value are maintained after pressure relief

Fig. 38: High-voltage arresters Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/27

Gas-Insulated Switchgear for Substations

Introduction 1

2

3

Common characteristic features of switchgear installation Because of its small size and outstanding compatibility with the environment, SF6 insulated switchgear (GIS) is gaining constantly on other types. Siemens has been a leader in this sector from the very start. The concept of SF6 - insulated metal-enclosed high-voltage switchgear has proved itself in more than 70,000 bay operating years in over 6,000 installations in all parts of the world. It offers the following outstanding advantages.

Protection of the environment The necessity to protect the environment often makes it difficult to erect outdoor switchgear of conventional design, whereas buildings containing compact SF6-insulated switchgear can almost always be designed so that they blend well with the surroundings. SF6-insulated metal-enclosed switchgear is, due to the modular system, very flexible and can meet all requirements of configuration given by network design and operating conditions.

Each circuit-breaker bay includes the full complement of disconnecting and grounding switches (regular or make-proof), instrument transformers, control and protection equipment, interlocking and monitoring facilities commonly used for this type of installation (Fig. 39). Beside the conventional circuit-breaker bay, other arrangements can be supplied such as single-bus, ring cable with load-break switches and circuit-breakers, single-bus arrangement with bypass-bus, coupler and bay for triplicate bus. Combined circuitbreaker and load-break switch feeder, ring cable with load-break switches, etc. are furthermore available for the 145 kV level.

Minimal space requirements

4

5

6

The availability and price of land play an important part in selecting the type of switchgear to be used. Siting problems arise in ■ Large towns ■ Industrial conurbations ■ Mountainous regions with narrow valleys ■ Underground power stations In cases such as these, SF6-insulated switchgear is replacing conventional switchgear because of its very small space requirements. Full protection against contact with live parts

7

The all-round metal enclosure affords maximum safety for personnel under all operating and fault conditions. Protection against pollution

8

9

10

Its metal enclosure fully protects the switchgear interior against environmental effects such as salt deposits in coastal regions, industrial vapors and precipitates, as well as sandstorms. The compact switchgear can be installed in buildings of uncomplicated design in order to minimize the cost of cleaning and inspection and to make necessary repairs independent of weather conditions. Free choice of installation site The small site area required for SF6-insulated switchgear saves expensive grading and foundation work, e.g. in permafrost zones. Other advantages are the short erection times and the fact that switchgear installed indoors can be serviced regardless of the climate or the weather.

Fig. 39: Typical circuit arrangements of SF6-switchgear

2/28

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Gas-Insulated Switchgear for Substations

Main product range of GIS for substations SF6 switchgear up to 550 kV (the total product range covers GIS from 66 up to 800 kV rated voltage): Fig. 40. The development of the switchgear is always based on an overall production concept, which assures the achievement of the high technical standards required of the HV switchgear whilst providing the maximum customer benefit.

This objective is attained only by incorporating all processes in the quality management system, which has been introduced and certified according to DIN EN ISO 9001 (EN 29001). Siemens GIS switchgear meets all the performance, quality and reliability demands such as: Compact space-saving design means uncomplicated foundations, a wide range of options in the utilization of space, less space taken up by the switchgear.

Minimal-weight construction through the use of aluminum alloy and the exploitation of innovations in development such as computer-aided design tools.

1

Safe encapsulation means an outstanding level of safety based on new manufacturing methods and optimized shape of enclosures.

2

Environmental compatibility means no restrictions on choice of location through minimal space requirement, extremely low noise emission and effective gas sealing system (leakage < 1% per year per gas compartment).

3

Economical transport

3500

4740

means simplified and fast transport and reduced costs because of maximum possible size of shipping units. 4480

2850

3470

5170

500

Switchgear type

8DN8

8DN9

8DQ1

Details on page

2/30

2/31

2/32

4

Minimal operating costs means the switchgear is practically maintenance-free, e.g. contacts of circuit-breakers and disconnectors designed for extremely long endurance, motor-operated mechanisms self-lubricating for life, corrosion-free enclosure. This ensures that the first inspection will not be necessary until after 25 years of operation.

5

6

Reliability

Rated voltage

[kV]

up to 145

up to 245

up to 550

Rated powerfrequency withstand voltage

[kV]

up to 275

up to 460

up to 740

Rated lightning impulse withstand voltage

[kV]

up to 650

up to 1050

up to 1800

Rated switching impulse withstand voltage

[kV]

–

up to 850

up to 1250

Rated (normal) current [A] busbar

up to 3150

up to 3150

up to 6300

Rated (normal) current [A] feeder

up to 2500

up to 3150

up to 4000

Rated breaking current

[kA]

up to 40

up to 50

up to 63

Rated short-time withstand current

[kA]

up to 40

up to 50

up to 63

Rated peak withstand current

[kA]

up to 108

up to 135

up to 170

> 25

> 25

> 25

800

1200/1500

3600

means our overall product concept which includes, but is not limited to, the use of finite elements method (FEM), threedimensional design programs, stereolithography, and electrical field development programs assuring the high standard of quality. Smooth and efficient installation and commissioning

7

8

transport units are fully assembled and tested at the factory and filled with SF6 gas at reduced pressure. Plug connection of all switches, all of which are motorized, further improves the speediness of site installation and substantially reduces field wiring errors.

9

Routine tests

Inspection

[Years]

Bay width

[mm]

All dimensions in mm

All measurements are automatically documented and stored in the EDP information system, which enables quick access to measured data even if years have passed. For further information please contact: Fax: ++ 49- 9131-7-34498 e-mail: [email protected]

Fig. 40: Main product range

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/29

10

Gas-Insulated Switchgear for Substations

1

2

3

4

5

6

7

8

9

10

SF6-insulated switchgear up to 145 kV, type 8DN8 Three-phase enclosures are used for type 8DN8 switchgear in order to achieve extremely low component dimensions. The low bay weight ensures minimal floorloading and eliminates the need for complex foundations. Its compact dimensions and low weight enable it to be installed almost anywhere. This means that capital costs can be reduced by using smaller buildings, or by making use of existing ones, for instance when medium voltage switchgear is replaced by 145 kV GIS. The bay ist based on a circuit-breaker mounted on a supporting frame (Fig. 41). A special multifunctional cross-coupling module combines the functions of the disconnector and earthing switch in a threeposition switching device. It can be used as ■ an active busbar with integrated disconnector and work-in-progress earthing switch (Fig. 41/Pos. 3 and 4), ■ outgoing feeder module with integrated disconnector and work-in-progress earthing switch (Fig. 41/Pos. 5), ■ busbar sectionalizer with busbar earthing. For cable termination, a cable termination module can be equipped with either conventional sealing ends or the latest plug-in connectors (Fig. 41/Pos. 9). Flexible singlepole modules are used to connect overhead lines and transformers by using a splitting module which links the 3-phase encapsulated switchgear to the single pole connections. Thanks to the compact design, up to three completely assembled and works-tested bays can be shipped as one transport unit. Fast erection and commissioning on site ensure the highest possible quality. The feeder control and protection can be located in a bay-integrated local control cubicle, mounted in the front of each bay (Fig. 42). It goes without saying that we supply our gas-insulated switchgear with all types of currently available bay control systems – ranging from contactor circuit controls to digital processor bus-capable bay control systems, for example the modern SICAM HV system based on serial bus communication. This system offers ■ Online diagnosis and trend analysis enabling early warning, fault recognition and condition monitoring. ■ Individual parameterization, ensuring the best possible incorporation of customized control facilities. ■ Use of modern current and voltage sensors. This results in a longer service life and lower operating costs, in turn attaining a considerable reduction in life cycle costs.

2/30

7

1

2

8

6

Gas-tight bushing Gas-permeable bushing

10

5 4

9 3

5 Outgoing feeder module

1 Interrupter unit of the circuit-breaker 2 Spring-stored energy mechanism with circuit-breaker control unit 3 Busbar I with disconnector and earthing system 4 Busbar II with disconnector and earthing system

6 7 8 9 10

with disconnector and earthing switch Make-proof earthing switch (high-speed) Current transformer Voltage transformer Cable sealing end Integrated local control cubicle

3

4 1 7 5 8 6 9

Fig. 41: Switchgear bay 8DN8 up to 145 kV

Fig. 42: 8DN8 switchgear for rated voltage 145 kV

Fig. 43

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Gas-Insulated Switchgear for Substations

SF6-insulated switchgear up to 245 kV, type 8DN9 The clear bay configuration of the lightweight and compact 8DN9 switchgear is evident at first sight. Control and monitoring facilities are easily accessible in spite of the compact design of the switchgear. The horizontally arranged circuit-breaker forms the basis of every bay configuration. The operating mechanism is easily accessible from the operator area. The other bay modules – of single-phase encapsulated design like the circuit-breaker module – are located on top of the circuit-breaker. The three-phase encapsulated passive busbar is partitioned off from the active equipment. Thanks to “single-function” assemblies (assignment of just one task to each module) and the versatile modular structure, even unconventional arrangements can be set up out of a pool of only 20 different modules. The modules are connected to each other by a standard interface which allows an extensive range of bay structures. The switchgear design with standardized modules and the scope of services mean that all kinds of bay structures can be set up in a minimal area. The compact design permits the supply of double bays fully assembled, tested in the factory and filled with SF6 gas at reduced pressure, which assures smooth and efficient installation and commissioning. The following major feeder control level functions are performed in the local control cubicle for each bay, which is integrated in the operating front of the 8DN9 switchgear: ■ Fully interlocked local operation and state-indication of all switching devices managed reliably by the Siemens digital switchgear interlock system ■ Practical dialog between the digital feeder protection system and central processor of the feeder control system ■ Visual display of all signals required for operation and monitoring, together with measured values for current, voltage and power ■ Protection of all auxiliary current and voltage transformer circuits ■ Transmission of all feeder information to the substation control and protection system Factory assembly and tests are significant parts of the overall production concept mentioned above. Two bays at a time undergo mechanical and electrical testing with the aid of computer-controlled stands.

14

4

6

3

7

Gas-tight bushing Gas-permeable bushing

10

9

12

1

5

2

3

4

5

2 1 Circuit-breaker interrupter unit 2 Spring-stored energy 3 4 5 6 7

mechanism with circuit-breaker control unit Busbar disconnector I Busbar I Busbar disconnector II Busbar II Earthing switch (work-in-progress)

1

11 8

13

6

8 Earthing switch (work-in-progress)

9 Outgoing-disconnector 10 Make-proof earthing switch 11 12 13 14

(high-speed) Current transformer Voltage transformer Cable sealing end Integrated local control cubicle

3

5

7

7 1 11 8 9

12 10

8

13

Fig. 44: Switchgear bay 8DN9 up to 245 kV

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

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Fig. 45: 8DN9 switchgear for rated voltage 245 kV

2/31

Gas-Insulated Switchgear for Substations

1

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3

4

5

6

7

SF6-insulated switchgear up to 550 kV, type 8DQ1 The GIS type 8DQ1 is a modular switchgear system for high power switching stations with individual enclosure of all modules for the three-phase system. The base unit for the switchgear forms a horizontally arranged circuit-breaker on top of which are mounted the housings containing disconnectors, grounding switches, current transformers, etc. The busbar modules are also single-phase encapsulated and partitioned off from the active equipment. As a matter of course the busbar modules of this switchgear system are passive elements, too. Additional main characteristic features of the switchgear installation are: ■ Circuit-breakers with two interrupter units up to operating voltages of 550 kV and breaking currents of 63 kA (from 63 kA to 100 kA, circuit-breakers with four interrupter units have to be considered) ■ Low switchgear center of gravity by means of circuit-breaker arranged horizontally in the lower portion ■ Utilization of the circuit-breaker transport frame as supporting device for the entire bay ■ The use of only a few modules and combinations of equipment in one enclosure reduces the length of sealing faces and consequently lowers the risk of leakage

11 10

12

9 8

7

1

6

4 5 3 2

13 1 2 3 4 5 6 7 8

Circuit-breaker Busbar disconnector I Busbar I Busbar disconnector II Busbar II Grounding switch Voltage transformer Make-proof grounding switch 9 Cable disconnector

14 10 11 12 13 14 15 16 17 18

15

16 17 18

Grounding switch Current transformer Cable sealing end Local control cubicle Gas monitoring unit (as part of control unit) Circuit-breaker control unit Electrohydraulic operating unit Oil tank Hydraulic storage cylinder

3 5 2

4 6 1 11 10

9

7 8 12

Fig. 46: Switchgear bay 8DQ1 up to 550 kV

8

9

10

Fig. 47: 8DQ1 switchgear for rated voltage 420 kV

2/32

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Gas-Insulated Switchgear for Substations

Some examples for special arrangement Gas-insulated switchgear – usually accommodated in buildings (as shown in a towertype substation) – is expedient whenever the floor area is very expensive or restricted or whenever ambient conditions necessitate their use (Fig. 50, page 2/34). For smaller switching stations, or in cases of expansion when there is no advantage in constructing a building, a favorable solution is to install the substation in a container (Fig. 49).

1 Cable termination 2 Make-proof earthing 3 4 5 6

switch Outgoing disconnector Earthing switch Circuit breaker Earthing switch

7 Current transformer 8 Outgoing disconnector 9 Make-proof earthing switch 10 Voltage transformer 11 Outdoor termination

Fig. 49: 8DN9 switchgear bay in a container

Mobile containerized switching stations can be of single or multi-bay design using a large number of different circuits and arrangements. All the usual connection components can be employed, such as outdoor bushings, cable adapter boxes and SF6 tubular connections. If necessary, all the equipment for control and protection and for the local supply can be accommodated in the container. This allows exten-

2 3

2

4 5

3

6 7 8

Mobile containerized switchgear – even for high voltage At medium-voltage levels, mobile containerized switchgear is the state of the art. But even high-voltage switching stations can be built in this way and economically operated in many applications. The heart is the metal-enclosed SF6-insulated switchgear, installed either in a sheet-steel container or in a block house made of prefabricated concrete elements. In contrast to conventional stationary switchgear, there is no need for complicated constructions; mobile switching stations have their own ”building“.

1 1

9

4

10 11

5 Fig. 48: Containerized 8DN9 switchgear with stub feed in this example

sively independent operation of the installation on site. Containerized switchgear is preassembled in the factory and ready for operation. On site, it is merely necessary to set up the containers, fit the exterior system parts and make the external connections. Shifting the switchgear assembly work to the factory enhances the quality and operational reliability. Mobile containerized switchgear requires little space and usually fits in well with the environment. Rapid availability and short commissioning times are additional, significant advantages for the operators. Considerable cost reductions are achieved in the planning, construction work and assembly. Building authority approvals are either not required or only in a simple form. The installation can be operated at various locations in succession, and adaptation to local circumstances is not a problem. These are the possible applications for containerized stations: ■ Intermediate solutions for the modernization of switching stations ■ Low-cost transitional solutions when tedious formalities are involved in the new construction of transformer substations, such as in the procurement of land or establishing cable routes ■ Quick erection as an emergency station in the event of malfunctions in existing switchgear ■ Switching stations for movable, geothermal power plants

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

GIS up to 245 kV in a standard container The dimensions of the 8DN9 switchgear made it possible to accommodate all active components of the switchgear (circuitbreaker, disconnector, grounding switch) and the local control cabinet in a standard container. The floor area of 20 ft x 8 ft complies with the ISO 668 standard. Although the container is higher than the standard dimension of 8 ft, this will not cause any problems during transportation as proven by previously supplied equipment. German Lloyd, an approval authority, has already issued a test certificate for an even higher container construction. The standard dimensions and ISO corner fittings will facilitate handling during transport in the 20 ft frame of a container ship and on a low-loader truck. Operating staff can enter the container through two access doors. Rent a GIS Containerized gas-insulated high voltage substations for hire are now available. In this way, we can step into every breach, instantly and in a remarkably cost-effective manner. Whether for a few weeks, months or even 2 to 3 years, a fair rent makes our Instant Power Service unbeatably economical.

2/33

6

7

8

9

10

Gas-Insulated Switchgear for Substations

All dimensions in m

Specification guide for metal-enclosed SF6-insulated switchgear

Air conditioning system

1

26.90

2

The points below are not considered to be comprehensive, but are a selection of the important ones.

Relay room

General 23.20

3

4 Gas-insulated switchgear type 8DN9

Grounding resistor

5 15.95 13.8 kV switchgear

6

Applicable standards

Shunt reactor 11.50

7 Cable duct

8.90

8

Radiators 40 MVA transformer

10 2.20

–1.50 Fig. 50: Special arrangement for limited space. Sectional view of a building showing the compact nature of gas-insulated substations

2/34

All equipment shall be designed, built, tested and installed to the latest revisions of the applicable IEC 60 standards (IEC Publ. 60517 “High-voltage metal-enclosed switchgear for rated voltages of 72.5 kV and above”, IEC Publ. 60129 “Alternating current disconnectors (isolators) and grounding switches”, IEC Publ. 60056 “High-voltage alternating-current circuitbreakers”), and IEC Publ. 60044 for instrument transformers. Local conditions

Compensator

9

These specifications cover the technical data applicable to metal-enclosed SF6 gasinsulated switchgear for switching and distribution of power in cable and/or overhead line systems and at transformers. Key technical data are contained in the data sheet and the single-line diagram attached to the inquiry. A general “Single-line diagram” and a sketch showing the general arrangement of the substation and the transmission line exist and shall form part of a proposal. The switchgear quoted shall be complete to form a functional, safe and reliable system after installation, even if certain parts required to this end are not specifically called for.

The equipment described herein will be installed indoors. Suitable lightweight, prefabricated buildings shall be quoted if available from the supplier. Only a flat concrete floor will be provided by the buyer with possible cutouts in case of cable installation. The switchgear shall be equipped with adjustable supports (feet). If steel support structures are required for the switchgear, these shall be provided by the supplier. For design purposes indoor temperatures of – 5 °C to +40 °C and outdoor temperatures of – 25 °C to +40 °C shall be considered. For parts to be installed outdoors (overhead line connections) the applicable conditions in IEC Publication 60517 shall also be observed.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Gas-Insulated Switchgear for Substations

Work, material and design Aluminium or aluminium alloys shall be used preferabely for the enclosures. Maximum reliability through minimum amount of erection work on site is required. Subassemblies must be erected and tested in the factory to the maximum extent. The size of the subassemblies shall be limited only by the transport conditions. The material and thickness of the enclosure shall be selected to withstand an internal arc and to prevent a burn-through or puncturing of the housing within the first stage of protection, referred to a shortcircuit current of 40 kA. Normally exterior surfaces of the switchgear shall not require painting. If done for aesthetic reasons, surfaces shall be appropriately prepared before painting, i.e. all enclosures are free of grease and blasted. Thereafter the housings shall be painted with no particular thickness required but to visually cover the surface for decorative reasons only. The interior color shall be light (white or light grey). All joints shall be machined and all castings spotfaced for bolt heads, nuts and washers. Assemblies shall have reliable provisions to absorb thermal expansion and contractions created by temperature cycling. For this purpose metal bellows-type compensators shall be installed. They must be provided with adjustable tensioners. All solid post insulators shall be provided with ribs (skirts). For supervision of the gas within the enclosures, density monitors with electrical contacts for at least two pressure levels shall be installed. The circuit-breakers, however, might be monitored by density gauges fitted in circuit-breaker control units. The manufacturer assures that the pressure loss within each individual gas compartment – and not referred to the total switchgear installation only – will be not more than 1% per year per gas compartment.

Each gas-filled compartment shall be equipped with static filters of a capacity to absorb any water vapor penetrating into the switchgear installation over a period of at least 25 years. Long intervals between the necessary inspections shall keep the maintenance cost to a minimum. A minor inspection shall only become necessary after ten years and a major inspection preferably after a period exceeding 25 years of operation, unless the permissible number of operations is met at an earlier date. Arrangement and modules Arrangement The arrangement shall be single-phase or three-phase enclosed. The assembly shall consist of completely separate pressurized sections designed to minimize the risk of damage to personnel or adjacent sections in the event of a failure occurring within the equipment. Rupture diaphragms shall be provided to prevent the enclosures from uncontrolled bursting and suitable deflectors provide protection for the operating personnel. In order to achieve maximum operating reliability, no internal relief devices may be installed because adjacent compartments would be affected. Modular design, complete segregation, arc-proof bushings and “plug-in” connection pieces shall allow ready removal of any section and replacement with minimum disturbance of the remaining pressurized switchgear. Busbars All busbars shall be three-phase or singlephase enclosed and be plug-connected from bay to bay. Circuit-breakers The circuit-breaker shall be of the single pressure (puffer) type with one interrupter per phase*. Heaters for the SF6 gas are not permitted. The arc chambers and contacts of the circuit-breaker shall be freely accessible. The circuit-breaker shall be designed to minimize switching overvoltages and also to be suitable for out-of-phase switching. The specified arc interruption performance must be consistent over the entire operating range, from line-charging currents to full short-circuit currents.

The circuit breaker shall be designed to withstand at least 18–20 operations (depending on the voltage level) at full short-circuit rating without the necessity to open the circuit-breaker for service or maintenance. The maximum tolerance for phase disagreement shall be 3 ms, i.e. until the last pole has been closed or opened respectively after the first. A standard station battery required for control and tripping may also be used for recharging the operating mechanism. The energy storage system (hydraulic or spring operating system) will hold sufficient energy for all standard IEC closeopen duty cycles. The control system shall provide alarm signals and internal interlocks, but inhibit tripping or closing of the circuit-breaker when there is insufficient energy capacity in the energy storage system, or the SF6 density within the circuit-breaker has dropped below a minimum permissible level. Disconnectors All isolating switches shall be of the singlebreak type. DC motor operation (110, 125, 220 or 250 V), completely suitable for remote operation, and a manual emergency drive mechanism is required. Each motor-drive shall be self-contained and equipped with auxiliary switches in addition to the mechanical indicators. Life lubrication of the bearings is required. Grounding switches Work-in-progress grounding switches shall generally be provided on either side of the circuit-breaker. Additional grounding switches may be used for the grounding of bus sections or other groups of the assembly. DC motor operation (110, 125, 220 or 250 V), completely suitable for remote operation, and a manual emergency drive mechanism is required. Each motor drive shall be self-contained and equipped with auxiliary position switches in addition to the mechanical indicators. Life lubrication of the bearings is required.

* two interrupters for voltages exceeding 245 kV Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/35

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Gas-Insulated Switchgear for Substations

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Make-proof high-speed grounding switches shall generally be installed at cable and overhead-line terminals. DC motor operation (110, 125, 220 or 250 V), completely suitable for remote operation, and a manual emergency drive mechanism is required. Each motor drive shall be self-contained and equipped with auxiliary position switches in addition to the mechanical indicators. Life lubrication of the bearings is required. These switches shall be equipped with a rapid closing mechanism to provide faultmaking capability. Instrument transformers Current transformers (CTs) shall be of the dry-type design not using epoxy resin as insulation material. Cores shall be provided with the accuracies and burdens as shown on the SLD. Voltage transformers shall be of the inductive type, with ratings up to 200 VA. They shall be foil-gas-insulated. Cable terminations Single or three-phase, SF6 gas-insulated, metal-enclosed cable-end housings shall be provided. The stress cone and suitable sealings to prevent oil or gas from leaking into the SF6 switchgear are part of the cable manufacturer’s supply. A mating connection piece, which has to be fitted to the cable end, shall be made available by the switchgear supplier. The cable end housing shall be suitable for oil-type, gas-pressure-type and plasticinsulated (PE, PVC, etc.) cables as specified on the SLD, or the data sheets. Facilities to safely isolate a feeder cable and to connect a high-voltage test cable to the switchgear or the cable shall be provided.

Fig. 52: Cable termination module – Cable termination modules conforming to IEC are available for connecting the switchgear to high-voltage cables. The standardized construction of these modules allows connection of various cross-sections and insulation types. Parallel cable connections for higher rated currents are also possible using the same module.

Fig. 54: Transformer/reactor termination module – These termination modules form the direct connection between the GIS and oil-insulated transformers or reactance coils. They can be matched economically to various transformer dimensions by way of standardized modules.

Overhead line terminations Terminations for the connection of overhead lines shall be supplied complete with SF6-to-air bushings, but without line clamps.

9

Fig. 55: Transformer termination modules

Control

10

Fig. 51: Three phase cable termination module. Example for plug-in type cables.

2/36

Fig. 53: Outdoor termination module – High-voltage bushings are used for transition from SF6-to-air as insulating medium. The bushings can be matched to the particular requirements with regard to arcing and creepage distances. The connection with the switchgear is made by means of variabledesign angular-type modules.

An electromechanical or solid-state interlocking control board shall be supplied as a standard for each switchgear bay. This failsafe interlock system will positively prevent maloperations. Mimic diagrams and position indicators shall give clear demonstration of the operation to the operating personnel. Provisions for remote control shall be supplied.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Gas-Insulated Switchgear for Substations

Tests required

Power frequency tests

Partial discharge tests

Each assembly shall be subjected to power-frequency withstand tests to verify the correct installation of the conductors and also the fact that the insulator surfaces are clean and the switchgear as a whole is not polluted inside.

All solid insulators fitted into the switchgear shall be subjected to a routine partial discharge test prior to being installed. No measurable partial discharge is allowed at 1.1 line-to-line voltage (approx. twice the phase-to-ground voltage). This test ensures maximum safety against insulator failure, good long-term performance and thus a very high degree of reliability. Pressure tests Each cast aluminium enclosure of the switchgear shall be pressure-tested to at least double the service pressure.

Additional technical data The supplier shall point out all dimensions, weights and other applicable data of the switchgear that may affect the local conditions and handling of the equipment. Drawings showing the assembly of the switchgear shall be part of the quotation.

Leakage tests

Instructions

Leakage tests performed on the subassemblies shall ensure that the flanges and cover faces are clean, and that the guaranteed leakage rate will not be exceeded.

Detailed instruction manuals about installation, operation and maintenance of the equipment shall be supplied by the contractor in case of an order.

Fig. 56: The modular system of the 8DQ1 switchgear enables all conceivable customer requirements to be met with just a small number of components

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Scope of supply For all types of GIS Siemens supplies the following items and observes these interface points: ■ Switchgear bay with circuit-breaker interrupters, disconnectors and grounding switches, instrument transformers, and busbar housings as specified. For the different feeder types, the following limits apply: – Overhead line feeder: the connecting stud at the SF6-to-air bushing without the line clamp. – Cable feeder: according to IEC 60859 the termination housing, conductor coupling, and connecting plate are part of the GIS delivery, while the cable stress cone with matching flange is part of the cable supply (see Fig. 52 on page 2/36). – Transformer feeder: connecting flange at switchgear bay and connecting bus ducts to transformer including any expansion joint are delivered by Siemens. The SF6to-oil bushings plus terminal enclosures are part of the transformer delivery, unless agreed otherwise (see Fig. 54 on page 2/36)*. ■ Each feeder bay is equipped with grounding pads. The local grounding network and the connections to the switchgear are in the delivery scope of the installation contractor. ■ Initial SF6-gas filling for the entire switchgear as supplied by Siemens is included. All gas interconnections from the switchgear bay to the integral gas service and monitoring panel are supplied by Siemens as well. ■ Hydraulic oil for all circuit-breaker operating mechanisms is supplied with the equipment. ■ Terminals and circuit protection for auxiliary drive and control power are provided with the equipment. Feeder circuits and cables, and installation material for them are part of the installation contractor’s supply. ■ Local control, monitoring, and interlocking panels are supplied for each circuitbreaker bay to form completely operational systems. Terminals for remote monitoring and control are provided. ■ Mechanical support structures above ground are supplied by Siemens; embedded steel and foundation work is part of the installation contractor’s scope. * Note: this interface point should always be closely coordinated between switchgear manufacturer and transformer supplier.

2/37

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Gas-Insulated Transmission Lines (GIL)

Introduction 1

2

3

4

5

6

7

8

9

10

For high-power transmission systems where overhead lines are not suitable, alternatives are gas-insulated transmission lines (GIL). The GIL exhibits the following differences in comparison with cables: ■ High power ratings (transmission capacity up to 3000 MVA per System) ■ High overload capability ■ Suitable for long distances (100 km and more without compensation of reactive power) ■ High short-circuit withstand capability (including internal arc faults) ■ Possibility of direct connection to gasinsulated switchgear (GIS) and gas-insulated arresters without cable entrance fitting ■ Multiple earthing points possible ■ Non-flammable, no fire risk in case of failures The innovations in the latest Siemens GIL development are the considerable reduction of costs and the introduction of buried laying technique for GIL for long-distance power transmission. SF6 has been replaced by a gas mixture of SF6 and N2 as insulating medium.

The gas-insulated transmission line technique is a highly reliable system in terms of mechanical and electrical failures. Once a system is commissioned and in service, it runs reliably without any dielectrical or mechanical failures as experience over the course of 20 years shows. For example, one particular Siemens GIL will not undergo its scheduled inspection after 20 years of service, as there has been no indication of any weak point. Fig. 57 shows the arrangement of six phases in a tunnel. Basic design In order to meet mechanical stability criteria, gas-insulated lines need minimum cross-sections of enclosure and conductor. With these minimum cross-sections, high power transmission ratings are given. Due to the gas as insulating medium, low capacitive loads are given so that compensation of reactive power is not needed, even for long distances of 100 km and more.

Fig. 57: GIL arrangement in the tunnel of the Wehr pumped storage station (4000 m length, in service since 1975)

Siemens experience Back in the 1960s with the introduction of sulphur hexafluoride (SF6) as an insulating and switching gas, the basis was found for the development of gas-insulated switchgear (GIS). On the basis of GIS experience, Siemens developed SF6 gas-insulated lines to transmit electrical energy too. In the early 1970s initial projects were planned and implemented. Such gas-insulated lines were usually used within substations as busbars or bus ducts to connect gas-insulated switchgear with overhead lines, the aim being to reduce clearances in comparison to air-insulated overhead lines. Implemented projects include GIL laying in tunnels, in sloping galleries, in vertical shafts and in open air installation. Flanging as well as welding has been applied as jointing technique.

2/38

Fig. 58: Long-term test set-up at the IPH, Berlin

Reduction of SF6 content Several tests have been carried out in Siemens facilities as well as in other test laboratories world-wide since many years. Results of these investigations show that the bulk of the insulating gas for industrial projects involving a considerable amount of gas should be nitrogen, a nontoxic natural gas. However, another insulating gas should be added to nitrogen in order to improve the insulating capability and to minimize size and pressure. A N2/SF6 gas mixture with high nitrogen content (and sulphur hexafluoride portion as low as possible) was finally chosen as insulating medium.

The characteristics of N2/SF6 gas mixtures show that with an SF6 content of only 15–25% and a slightly higher pressure, the insulating capability of pure SF6 can be attained. Besides, the arcing behavior is improved through this mixture. Tests have proven that there would be no external damage or fire caused by an internal failure. The technical data of the GIL are shown in Fig. 59.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Gas-Insulated Transmission Lines (GIL)

Technical data

1 Rated voltage

up to 550 kV

Rated current lr

2000 – 4600 A

Transmission capacity

1500 – 3000 MVA

Capacitance

≈ 60 nF/km

Typical length

1–100 km

Gas mixture SF6/N2 ranging from

10%/90% up to 35%/65%

Laying

D

2

directly buried

Fig. 60: GIL laying technique

in tunnels/ sloping galleries/ vertical shafts

clean assembly and productivity is enhanced by a high level of automation of the overall process.

open air installation

Anti-corrosion protection

Fig. 59: GIL technical data

Jointing technique In order to improve the gas-tightness and to facilitate laying, flanges have been avoided as jointing technique. Instead, welding has been chosen to join the various GIL construction units. The welding process is highly automated, with the use of an orbital welding machine to ensure high quality of the joints. This orbital welding machine contributes to high productivity in the welding process and therefore speeds up laying. The reliability of the welding process is controlled by an integrated computerized quality assurance system. Laying The most recently developed Siemens GILs are scheduled for directly buried laying. The laying technique must be as compatible as possible with the landscape and must take account of the sequence of seasons. The laying techniques for pipelines have been improved over many years and they are applicable for GIL as a ”pipeline for electrical current“too. However, the GIL needs slightly different treatment where the pipeline technique has to be adapted.The laying process is illustrated in Fig. 60. The assembly area needs to be protected against dust, particles, humidity and other environmental factors that might disturb the dielectric system. Clean assembly therefore plays an important role in setting up cross-country GILs under normal environmental conditions. The combination of

Directly buried gas-insulated transmission lines will be safeguarded by a passive and active corrosion protection system. The passive corrosion protection system comprises a PE or PP coating and assures at least 40 years of protection. The active corrosion protection system provides protection potential in relation to the aluminum sheath. An important requirement taken into account is the situation of an earth fault with a high current of up to 63 kA to earth. Testing The GIL is already tested according to the report IEC 61640 (1998) “Rigid highvoltage, gas-insulated transmission lines for voltages of 72.5 kV and above.” Long-term performances Besides nearly 25 years of field experience with GIL installations world wide, the longterm performance of the GIL for long-distance installations has been proven by the independent test laboratory IPH, Berlin, Germany and the Berlin power utility BEWAG according to long-term test proce-

dures for power cables. The test procedure consisted of load cycles with doubled voltage and increased current as well as frequently repeated high-voltage tests. The assembly and repair procedures under realistic site conditions were examined too. The Siemens GIL is the first one in the world that has passed these tests, without any objection. Fig. 58 shows the test setup arranged in a tunnel of 3 m diameter, corresponding to the tunnel used in Berlin for installing a 420 kV transmission link through the city.

3

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6

References Siemens has gathered experience with gas-insulated transmission lines at rated voltages of up to 550 kV and with system lengths totalling more than 30 km. The first GIL stretch built by Siemens was the connection of the turbine generator/ pumping motor of a pumped storage station with the switchyard. The 420 kV GIL is laid in a tunnel through a mountain and has a length of 4000 m (Fig. 57). This connection was commissioned in 1975 at the Wehr pumped storage station in the Black Forest in Southern Germany.

7

8

For further information please contact: Fax: ++ 49-9131-7-3 44 98 e-mail: [email protected]

9

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Fig. 61: Siemens lab prototype for dielectric tests

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/39

Overhead Power Lines

Introduction 1

2

3

4

Since the very beginning of electric power, overhead lines have constituted the most important component for transmission and distribution. Their portion of overall length of electric circuits depends on the voltage level as well as on local conditions and practice. In densely populated areas like Central Europe, underground cables prevail in the distribution sector and overhead power lines in the high-voltage sector. In other parts of the world, for example in North America, overhead lines are often used also for distribution purposes within cities. Siemens has planned, designed and erected overhead power lines on all important voltage levels in many parts of the world.

2000

MW

Power per circuit

1000

750 kV

500

200

Selection of line voltage 5

6

7

8

9

10

For distribution and transmission of electric power standardized voltages according to IEC 60038 are used worldwide. For three-phase AC applications, three voltage levels are distinguished: ■ The low-voltage level up to 1 kV ■ The medium-voltage level between 1 kV and 36 kV and ■ The high-voltage level up to 800 kV. For DC transmission the voltages vary from the mentioned data. Low-voltage lines serve households and small business consumers. Lines on the medium-voltage level supply small settlements, individual industrial plants and larger consumers, the electric power being typically less than 10 MVA per circuit. The high-voltage circuits up to 145 kV serve for subtransmission of the electric power regionally and feed the mediumvoltage network. This high-voltage level network is often adopted to support the medium-voltage level even if the electric power is below 10 MVA. Moreover, some of these high-voltage lines also transmit the electric power from medium-sized generating stations, such as hydro plants on small and medium rivers, and supply largescale consumers, such as sizable industrial plants or steel mills. They constitute the connection between the interconnected high-voltage grid and the local distribution networks. The bandwidth of electrical power transported corresponds to the broad range of utilization, but, rarely exceeds 100 MVA per circuit, while the surge impedance load is 35 MVA (approximately).

2/40

380 kV

100

220 kV 50

20

110 kV Transmission distance 10 10

20

50

100

200

500 km

Fig. 62: Selection of rated voltage for power transmission

245 kV lines were used in Central Europe for interconnection of utility networks before the changeover to the 420 kV level for this purpose. Long-distance transmission, for example between the hydro power plants in the Alps and the consumers, was performed out by 245 kV lines. Nowadays, the importance of 245 kV lines is decreasing due to the application of 420 kV.

The 420 kV level represents the highest voltage used for AC transmission in Central Europe with the task of interconnecting the utility networks and of transmitting the energy over long distances. Some 420 kV lines connect the national grids of the individual European countries enabling Europewide interconnected network operation. Large power plants, such as nuclear stations, feed directly into the 420 kV network. The thermal capacity of the 420 kV circuits may reach 2000 MVA with a surge impedance load of approximately 600 MVA and a transmission capacity up to 1200 MVA.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Overhead Power Lines

Selection of conductors and ground wires

Rated voltage [kV]

20

110

220

380

750

Highest system voltage [kV]

24

123

245

420

800

Nominal cross-section

[mm2]

Conductor diameter

[mm]

Ampacity (at 80 °C conductor temperature) [A] Thermal capacity

[MVA]

150 300

bundle bundle bundle bundle 435 2x240 4x240 2x560 4x560

9.6 15.5 17.1 24.5

28.8 2x21.9 4x21.9 2x32.2 4x32.2

210

410

470 740

900

1290

2580

2080

4160

7

14

90 140

340

490

1700

1370

5400

0.030 0.026

0.013

50

120

Resistance at 20 °C [Ω/km] 0.59 0.24 0.19 0.10 0.067 0.059 Reactance at 50 Hz [Ω/km] 0.39 0.34 0.41 0.38

0.4

0.32

0.26

0.27

0.28

Effective capacitance

[nF/km]

9.7 11.2

9.3

10

9.5

11.5

14.4

13.8

13.1

Capacitance to ground

[nF/km]

3.4

3.6

4.0 4.2

4.8

6.3

6.5

6.4

6.1

[kVA/km]

1.2

1.4

35

38

145

175

650

625

2320

Ground-fault current [A/km] 0.04 0.04 0.25 0.25

0.58

0.76

1.35

1.32

2.48

[Ω]

360

310

375 350

365

300

240

250

260

[MVA]

–

–

35

135

160

600

577

2170

Charging power

Surge impedance Surge impedance load

32

Fig. 63: Electric characteristics of AC overhead power lines (Data refer to one circuit of a double-circuit line)

Overhead power lines with voltages higher than 420 kV are needed to economically transmit bulk electric power over long distances, a task typically arising when utilizing hydro energy potentials far away from consumer centers. Fig. 62 depicts schematically the range of application for the individual voltage levels depending on the distance of transmission and the power rating.

The voltage level has to be selected based on the duty of the line within the network or on results of network planning. Siemens has carried out such studies for utilities all over the world.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

1

Conductors represent the most important components of an overhead power line since they have to ensure economical and reliable transmission and contribute considerably to the total line costs. For many years aluminum and its alloys have been the prevailing conducting materials for power lines due to the favorable price, the low weight and the necessity of certain minimum cross-sections. The conductors are prone to corrosion. Aluminum, in principle, is a very corrosive metal. However, a dense oxide layer is formed which stops further corrosive attacks. Therefore, aluminum conductors are well-suited also for corrosive areas, for example a maritime climate. For aluminum conductors there are a number of different designs in use. All-aluminum conductors (AAC) have the highest conductivity for a given cross-section, however possess only a low mechanical strength, which limits their application to short spans and low tensile forces. To increase the mechanical strength, wires made of aluminum-magnesium-silicon alloys are adopted, the strength of which is twice that of pure aluminum. All-aluminum and aluminum alloy conductors have shown susceptibility against eolian vibrations. Compound conductors with a steel core, so-called aluminum cables, steel reinforced (ACSR), avoid this disadvantage. The ratio between aluminum and steel ranges from 4.3:1 to 11:1. Experience has demonstrated that ACSR has a long life, too. Conductors are selected according to electrical, thermal, mechanical and economic aspects. The electric resistance as a result of the conducting material and its crosssection is the most important feature affecting the voltage drop and the energy losses along the line and, therefore, the transmission costs. The cross-section has to be selected such that the permissible temperatures will not be exceeded during normal operation as well as under short circuit. With increasing cross-section the line costs increase, while the costs for losses decrease. Depending on the duty of a line and its power, a cross-section can be determined which results in lowest transmission costs. This cross-section should be aimed for. The heat balance of ohmic losses and solar radiation against convection and radiation determines the conductor temperature. A current density of 0.5 to 1.0 A /mm2 has proven to be an economical solution.

2/41

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9

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Overhead Power Lines

1

2

3

4

5

High voltage results in correspondingly high-voltage gradients at the conductors and in corona-related effects such as visible discharges, radio interference, audible noise and energy losses. When selecting the conductors, the voltage gradient has to be limited to values between 15 and 17 kV/cm. This aspect is important for lines with voltages of 245 kV and above. Therefore, bundle conductors are adopted for extra-high-voltage lines. Fig. 63 shows typical conductor configurations. From the mechanical point of view the conductors have to be designed for everyday conditions and for maximum loads exerted on the conductor by wind and ice. As a rough figure, an everyday stress of approximately 20% of the conductor ultimate tensile stress can be adopted, resulting in a limited risk of conductor damage. Ground wires can protect a line against direct lightning strokes and improve the system behavior in case of short circuits; therefore, lines with single-phase voltages of 110 kV and above are usually equipped with ground wires. Ground wires made of ACSR with a sufficiently high aluminum cross-section satisfy both requirements.

6

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2/42

Selection of insulators Overhead line insulators are subject to electrical and mechanical stress since they have to insulate the conductors from potential to ground and must provide physical supports. Insulators must be capable of withstanding these stresses under all conditions encountered in a specific line. The electrical stresses result from ■ The power frequency voltage ■ Temporary overvoltages at power frequency and ■ Switching and lightning overvoltages. Various insulator designs are in use, depending on the requirements and the experience with certain insulator types. Cap and pin-type insulators (Fig. 64) are made of porcelain or glass. The individual units are connected by fittings of malleable cast iron. The insulating bodies are not puncture-proof which is the reason for relatively numerous insulator failures. In Central Europe long-rod insulators (Fig. 65) are most frequently adopted. These insulators are puncture-proof. Failures under operation are extremely rare. Long-rod insulators show a superior behavior especially under pollution. The tensile loading of the porcelain body forms a disadvantage, which requires relatively large cross-sections. Composite insulators are made of a core with fiberglass-reinforced resin and sheds of differing plastic materials. They offer light weight and high tensile strength and will gain increasing importance for high-voltage lines. Insulator sets must provide a creepage path long enough for the expected pollution level, which is classified according to IEC 60815 from light with 16 mm/kV up to very heavy with 31 mm/kV. To cope with switching and lightning overvoltages, the insulator sets have to be designed with respect to insulation coordination according to IEC 60071-1. These design aspects determine the gap between the grounded fittings and the live parts. Suspension insulator sets carry the conductor weight and are arranged more or less vertically. There are I-shaped (Fig. 66a) and V-shaped sets in use. Single, double or triple sets cope with the mechanical loadings and the design requirements. Tension insulator sets (Fig. 66b, c) terminate the conductors and are arranged in the direction of the conductors. They are loaded by the conductor tensile force and have to be rated accordingly.

Fig. 64: Cap and pin-type insulator

Fig. 65: Long-rod insulator with clevis and tongue connection

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Overhead Power Lines

Cross arm

1

2

3

4

5

6

Conductor

7

Fig. 66a: I-shaped suspension insulator set for 245 kV

Cross arm

8

9

Fig. 66b: Double tension insulator set for 245 kV (elevation)

Cross arm

Conductor

10

Fig. 66c: Double tension insulator set for 245 kV (plan)

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/43

Overhead Power Lines

Selection and design of supports 1

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6

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8

9

10

Together with the line voltage, number of circuits and type of conductors the configuration of the circuits determines the design of overhead power lines. Additionally, lightning protection by ground wires, the terrain and the available space at the tower sites have to be considered. In densely populated areas like Central Europe, the width of right-of-way and the space for the tower sites are limited. In the case of extra-high voltages the conductor configuration affects the electrical characteristics and the transmission capacity of the line. Very often there are contradicting requirements, such as a tower height as low as possible and a narrow right-of-way, which can only be met partly by compromises. The mutual clearance of the conductors depends on the voltage and the conductor sag. In ice-prone areas conductors should not be arranged vertically in order to avoid conductor clashing after ice shedding. For low- and medium-voltage lines horizontal conductor configurations prevail which feature line post insulators as well as suspension insulators. Preferably poles made of wood, concrete or steel are used. Fig. 67 shows some typical line configurations. Ground wires are omitted at this voltage level. For high and extra-high-voltage power lines a large variety of configurations are available which depend on the number of circuits and on local conditions. Due to the very limited right-of-way, more or less all high-voltage lines in Central Europe comprise at least two circuits. Fig. 68 shows a series of typical tower configurations. Arrangement e) is called the ”Danube“ configuration and is most often adopted. It represents a fair compromise with respect to width of right-of-way, tower height and line costs. For lines comprising more than two circuits there are many possibilities for configuring the supports. In the case of circuits with differing voltages those circuits with the lower voltage should be arranged in the lowermost position (Fig. 68g). The arrangement of insulators depends on the task of a support within the line. Suspension towers support the conductors in straight-line sections and at small bends. This tower type results in the lowest costs; special attention should therefore be paid to using this tower type as often as possible.

a

b

c

d

Fig. 67: Configurations of medium-voltage supports

a

b

e

f

d

c

h

g

Fig. 68: Tower configurations for high-voltage lines

2/44

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Overhead Power Lines

Angle towers have to carry the conductor tensile forces at angle points of the line. The tension insulator sets permanently exert high forces on the supports. Various loading conditions have to be met when designing angle towers. The climatic conditions are a determining factor as well. Finally, dead-end towers are used at the ends of a transmission line. They carry the total conductor tensile forces of the connection to the substations. Depending on the size of the supports and the acting forces, differing designs and materials are adopted. Poles made of wood, concrete or steel are very often used for low and medium-voltage lines. Towers with lattice steel design, however, prevail at voltage levels of 110 kV and above (Fig. 69). When designing the support a number of conditions have to be considered. High wind and ice loads cause the maximum forces to act on suspension towers. In ice-prone areas unbalanced conductor tensile forces can result in torsional loading. Additionally, special loading conditions are adopted for the purpose of failure containment, i.e. to limit the extent of damage. Finally, provisions have to be made for construction and maintenance conditions. Siemens adopts modern computer programs for tower design in order to optimize the structures, select components and joints and determine foundation loadings. The stability of the support poles and towers needs also accordingly designed foundations. The type of towers and poles, the loads, the soil conditions as well as the accessibility to the line route and the availability of machinery determine the selection and design of foundation. Concrete blocks or concrete piers are in use for poles which exert bending moments on the foundation. For towers with four legs a foundation is provided for each individual leg (Fig. 70). Pad-andchimney and concrete block foundations require good bearing soil conditions without ground water. Driven or augured piles and piers are adopted for low bearing soil, for sites with bearing soil in a greater depth and for high ground water level. In this case the soil conditions must permit pile driving. Concrete slabs can be used for good bearing soil, when subsoil and ground water level prohibit pad and chimney foundations as well as piles. Siemens can design all types of foundation and has the necessary equipment, such as pile drivers, grouting devices, soil and rock drills, at its command to build all types of power line foundations.

1

2

3

4

5 Fig. 69: Lattice steel towers of a high-voltage line

6 Pad-and-chimney foundation

Auger-bored foundation

7

8

Rock anchor foundation

9

Pile foundation

10

Fig. 70: Foundations for four-legged towers

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/45

Overhead Power Lines

f40=6.15 fE =6.60

302.50

1

300.70

6.07 5.74

2

f40= fE =

292.00

0.47

292.00

16.00 10.00

13.00

f40=2.11 282.00

16.20

1 1

279.00 2 T+0 DH

1 WA+0 DA

3

1 1

4

5

6

7

8 255.00 232.50

9

175.00 o. D.

286.50

276.50

273.50 273.00

281.50 0.0

0.1

0.0

10

132.0 106.0

M20 190.00g Left conductor 251.47 m 171°0´ 60.0m 50g 6.0 6.0 60.0m

283.00 275.50 270.50 270.00 265.00 284.50 275.00 270.50 272.50 267.50 264.00

0.2

66.0 36.0

190.00g

280.00 280.50

194.0 166.0

251.0 20 kV line

0.3

462

42

Ro at

M21

Fig. 71: Line profile established by computer

2/46

0.4

264.0 302.0 331.0 360.0 405.0 251.0 291.0 316.0 346.0 386.0 426.0

4.0 4.0

263.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

0 64.00

Overhead Power Lines

1 f40=17.46 fE =16.52

284.20 17.30 16.75 16.38 15.86

11.38 12.29 263.00

Arable land

Stream

Meadow

Road

Fallow land

Forest

2

Ground wire: ACSR 265/35 * 80.00 N/mm2 Conductor: ACSR 265/35 * 80.00 N/mm2 Equivalent sag: 11.21 m at 40 °C Equivalent span: 340.44 m

7.55 8.44

3

Bushes, height up to 5 m

4

24.20 f40=5.56 fE =5.87

5 4 WA+0 DA

6

223.00

7 1.45 16.00

8 270.00 292.50 263.00 266.50

4

0 426.0

3 T+8 DH

265.50 264.00

261.50

0.5 462.0

258.50

260.00 260.00 260.00

626.0

666.0 688.0 676.0

0.6

534.0 506.0 544.0

236.00 247.50

0.7

586.0

0.8 776.0 744.0

Road to XXX 425.0

13.9g

4.0 4.0

Road crossing at km 10.543

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

223.00 229.00 215.50

234.0

9

209.00 207.00 0.9

826.0 804.0 848.0

904.0 910.0

10

Left conductor 235.45 m 169.00g 152°6´ 5.8 5.8 169.00g

2/47

Overhead Power Lines

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Route selection and tower spotting

Siemens’ activities and experience

Route selection and planning represent increasingly difficult tasks since the rightof-way for transmission lines is limited and many aspects and interests have to be considered. Route selection and approval depend on the statutory conditions and procedures and always involve iterative studies carried out in the office and surveys in the terrain which consider and evaluate a great variety of alternatives. After definition of the route the longitudinal profile has to be surveyed, identifying all crossings over roads, rivers, railways, buildings and other overhead power lines. The results are evaluated with computer programs to calculate and plot the line profile. The towers are spotted by means of computer programs as well, which take into account the conductor sags under different conditions, the ground clearances, objects crossed by the line, technical data of the available tower range, tower and foundation costs and costs for compensation of landowners. The result is an economical design of a line, which accounts for all the technical and environmental conditions. Line planning forms the basis for material acquisition and line erection. Fig. 71 shows a line profile established by computer.

Siemens has been active in the overhead power line field for more than 100 years. The activities comprise design and construction of rural electrification schemes, low and medium-voltage distribution lines, high-voltage lines and extra-high-voltage installations. To give an indication of what has been carried out by Siemens, approximately 20,000 km of high-voltage lines up to 245 kV and 10,000 km of extra-high-voltage lines above 245 kV have been set up so far. Overhead power lines have been erected by Siemens in Germany and Central Europe as well as in the Middle East, Africa, the Far East and South America. The 420 kV transmission lines across the Elbe river in Germany comprising four circuits and requiring 235 m tall towers as well as the 420 kV line across the Bosphorus in Turkey with a span of approximately 1800 m (Fig. 72) are worthy of special mention. For further information please contact: Fax: ++ 49 - 9131- 33 5 44 e-mail: heinz-juergen.theymann@erls04. siemens.de

7 BT1

BS1

BS BT

suspension tower tension tower

BS2

BT2

8 37.5 124

124

9 27.5

10 119

112

70

162.5

125

Dimensions in m 674

1757

Europe

Bosphorus

668

Asia

Fig. 72: 420 kV line across the Bosphorus, longitudinal profile

2/48

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

High-Voltage Direct Current Transmission

HVDC When technical and/or economical feasibility of conventional high voltage AC transmission technology reach their limits, high voltage DC can offer the solution, namely ■ For economical transmission of bulk power over long distances ■ For interconnection of asynchronous power grids ■ For power transmission across the sea, when a cable length is long ■ For interconnection of synchronous but weak power grids, adding to their stability ■ For additional exchange of active power with other grids without having to increase the short-circuit power of the system ■ For increasing the transmission capacity of existing rights-of-way by changing from AC to DC transmission system Siemens offers HVDC systems as ■ Back-to-Back (B/B) stations to interconnect asynchronous networks, without any DC transmission line in between ■ Power transmission via Dc submarine cables ■ Power transmission via long-distance DC overhead lines

1

2

3

4 Fig. 76: Earthquake-proof, fire-retardant thyristor valves in Sylmar East, Los Angeles

Fig. 75: Long-distance transmission

Special features Back-to-Back (B/B): To connect asynchronous high voltage power systems or systems with different frequencies. To stabilize weak AC links or to supply even more active power, where the AC system reaches the limit of short-circuit capability.

Fig. 73: Back-to-back link between asynchronous grids

Cable transmission (CT): To transmit power across the sea with cables to supply islands/offshore platforms from the mainland and vice-versa.

Fig. 74: Submarine cable transmission

Long-distance transmission (LD): For transmission of bulk power over long distances (beyond approx. 600 km, considered as the break-even distance).

5

systems for all functions. Redundant design for fault-tolerant systems.

Valve technology ■ Simple, easy-to-maintain mechanical design ■ Use of fire-retardant, self-extinguishing material ■ Minimized number of electrical connections ■ Minimized number of components ■ Avoidance of potential sources of failure ■ ”Parallel“ cooling for the valve levels ■ Oxygen-saturated cooling water. After more than 20 years of operation, thyristor valves based on this technology have demonstrated their excellent reliability. ■ The recent introduction of direct lighttriggered thyristors with integrated overvoltage protection further simplifies the valve and reduces maintenance requirements. Control system In our HVDC control system, high-performance components with proven records in many other standard fields of application have been integrated, thus adding to the overall reliability of the system. Use of ”state-of-the-art“ microprocessor

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Filter technology Single, double and triple-tuned as well as high-pass passive filters, or any combination thereof, can be installed. Active filters, mainly for the DC circuit, are available. Wherever possible, identical filters are selected so that the performance does not significantly change when one filter has to be switched off. Turnkey service Our experienced staff are prepared to design, install and commission the whole HVDC system on a turnkey basis.

6

7

8

Project financing We are in a position to assist our customers in finding proper project financing, too. General services ■ Extended support to customers from the very beginning of HVDC system planning including – Feasibility studies – Drafting the specification – Project execution – System operation and – Long-term maintenance – Consultancy on upgrading/replacement of components/redesign of older schemes, e.g. retrofit of mercury-arc valves or relay-based controls

2/49

9

10

High-Voltage Direct Current Transmission

■ Studies during contract execution on:

1

2

3

4

5

6

7

– HVDC systems basic design – System dynamic response – Load flow and reactive power balance – Harmonic voltage distortion – Insulation coordination – Interference of radio and PLC – Special studies, if any Typical ratings Some typical ratings for HVDC schemes are given below for orientation purposes only: B/B: 100 ... 600 MW CT: 100 ... 800 MW LD: 300 ... 3000 MW (bipolar), whereby the lower rating is mainly determined by economic aspects and the higher one limited by the constraints of the interconnected networks. Innovations In recent years, the following innovative technologies and equipment have for example been successfully implemented by Siemens in diverse HVDC projects worldwide: ■ Direct light-triggered thyristors (already mentioned above) ■ Hybrid-optical DC measuring system (Fig. 77) ■ Active harmonic filters ■ Advanced eletrode line monitoring of bipolar HVDC systems ■ An SF6 HVDC circuit-breaker for use as Metallic Return Transfer Breaker, developed from a standard AC high-voltage breaker.

8

2

9

3 1

10

Fig. 78: HVDC outdoor valves, 533 kV (Cahora Bassa Rehabilitation, Southern Africa)

Rehabilitation and modernization of existing HVDC stations (Fig. 78) The integration of state-of-the-art microprocessor systems or thyristors allows the owner better utilization of his investment, e.g. ■ Higher availability ■ Fewer outages ■ Lower losses ■ Better performance values ■ Less maintenance. Higher availability means more operating hours, better utilization and higher profits for the owner. The new Human-Machine Interface (HMI) system enhances the user-friendliness and increases the reliability considerably due to the operator guidance. This rules out maloperation by the operator, because an incorrect command will be ignored by the HMI.

Fig. 77: Conventional DC measuring device (1) vs. the new hybrid-optical device (2) with composite insulator (3) shows the reduced space requirement for the new system (installed at HVDC converter station Sylmar, USA)

2/50

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

High-Voltage Direct Current Transmission

For further information please contact: Fax: ++ 49 - 9131- 73 45 52 e-mail: [email protected]

1

2

3

4

5

HMI

GPS

6 LAN

7 VCS Pole 1

SER

HMI GPS OLC CLC VBE VCS SER

Human-machine Interface Global Positioning System Open-Loop Control Closed-Loop Control Valve Base Electronics Valve Cooling Systems Sequence of Event Recording TFR Transient Fault Recording LAN Local Area Network

OLC Pole 1

OLC SC

CLC VBE Pole 1

OLC Pole 2

CLC VBE Pole 2

VCS Pole 2

8

Communication link to the load dispatch center

9 Communication link to the remote station

TFR

DC Protection

TFR

Communication link to the remote station

10 DC Yard

Fig. 79: Human-Machine Interface with structure of HVDC control system

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/51

Power Compensation in Transmission Systems

Introduction 1

2

3

4

5

In many countries increasing power consumption leads to growing and more interconnected AC power systems. These complex systems consist of all types of electrical equipment, such as power plants, transmission lines, switchgear transformers, cables etc., and the consumers. Since power is often generated in those areas of a country with little demand, the transmission and distribution system has to provide the link between power generation and load centers. Wherever power is to be transported, the same basic requirements apply: ■ Power transmission must be economical ■ The risk of power system failure must be low ■ The quality of the power supply must be high However, transmission systems do not behave in an ideal manner. The systems react dynamically to changes in active and reactive power, influencing the magnitude and profile of the power systems voltage. Fig. 80: STATCOM inverter hall

6

7

8

9

10

Examples: ■ A load rejection at the end of a long-dis-

tance transmission line will cause high overvoltages at the line end. However, a high load flow across the same line will decrease the voltage at its end. ■ The transport of reactive power through a grid system produces additional losses and limits the transmission of active power via overhead lines or cables. ■ Load-flow distribution on parallel lines is often a problem. One line could be loaded up to its limit, while another only carries half or less of the rated current. Such operating conditions limit the actual transmittable amount of active power. ■ In some systems load switching and/or load rejection can lead to power swings which, if not instantaneously damped, can destabilize the complete grid system and then result in a “Black Out”. Reactive power compensation helps to avoid these and some other problems. In order to find the best solution for a grid system problem, studies have to be carried out simulating the behavior of the system during normal and continuous operating conditions, and also for transient events. Study facilities which cover digital simulations via computer as well as analog ones in a transient network analyzer laboratory are available at Siemens.

2/52

Further information please contact: Fax: ++ 49 - 9131- 73 45 54 e-mail: [email protected]

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Power Compensation in Transmission Systems

Types of reactive power compensation

Concept

Operating diagram

Parallel compensation

1 Un

1

Parallel compensation is defined as any type of reactive power compensation employing either switched or controlled units, which are connected parallel to the transmission network at a power system node. In many cases switched compensation (reactors, capacitor banks or filters) can provide an economical solution for reactive power compensation using conventional switchgear.

2

3

In comparison to mechanically-switched reactive power compensation, controlled compensation (SVC, Fig. 81) offers the advantage that rapid dynamic control of the reactive power is possible within narrow limits, thus maintaining reactive power balance. Fig. 82 is a general outline of the problemsolving applications of SVCs in high-voltage systems. STATCOM The availability of high power gate-turn-off (GTO) thyristors has led to the development of a Static Synchronous Compensator (STATCOM), Fig. 80, page 2/52. The STATCOM is an “electronic generator” of dynamic reactive power, which is connected in shunt with the transmission line (Fig. 83) and designed to provide smooth, continuous voltage regulation, to prevent voltage collapse, to improve transmission stability and to dampen power oscillations. The STATCOM supports subcycle speed of response (transition between full capacitive and full inductive rating) and superior performance during system disturbances to reduce system harmonics and resonances. Particular advantages of the equipment are the compact and modular construction that enables ease of siting and relocation, as well as flexibility in future rating upgrades (as grid requirements change) and the generation of reactive current irrespective of network voltage.

4

2

Static VAr compensator (SVC)

1 2 3 4

4

Iind

3

Icap

Transformer Thyristor-controlled reactor (TCR) Fixed connected capacitor/filter bank Thyristor-switched capacitor bank (TSC)

4

Fig. 81: Static VAr compensator (SVC)

5 Voltage control Reactive power control Overvoltage limitation at load rejection Improvement of AC system stability Damping of power oscillations Reactive power flow control Increase of transmission capability Load reduction by voltage reduction Subsynchronous oscillation damping

6

7

Fig. 82: Duties of SVCs

8 Concept

Operating diagram

UN

UN

I

9

US

10

Id UD

Iind

Icap

Fig. 83: STATCOM

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/53

Power Compensation in Transmission Systems

1

2

3

4

5

6

Series compensation

Synchronous Series Compensation (SSSC)

Series compensation is defined as insertion of reactive power elements into transmission lines. The most common application is the series capacitor.

The Static Synchronous Series Compensator (SSSC) is a solid-state voltage generator connected in series with the transmission line through an insertion transformer (Fig. 85). The generation of a boost voltage advancing or lagging behind the line current by 90° affects the voltage drop caused at the line reactance and can be used to dampen transient oscillations and control real power flow independent of the magnitude of the line current.

Thyristor-Controlled Series Compensation (TCSC) By providing continuous control of transmission line impendance, the Thyristor Controlled Series Compensation (TCSC, Fig. 84) offers several advantages over conventional fixed series capacitor installations. These advantages include: ■ Continuous control of desired compensation level ■ Direct smooth control of power flow within the network ■ Improved capacitor bank protection ■ Local mitigation of subsynchronous oscillations (SSR). This permits higher levels of compensation in networks where interactions with turbine-generator torsional vibrations or with other control or measuring systems are of concern. ■ Damping of electromechanical (0.5–2 Hz) power oscillations which often arise between areas in a large interconnected power network. These oscillations are due to the dynamics of interarea power transfer and often exhibit poor damping when the aggregate power transfer over a corridor is high relative to the transmission strength.

Concept

Operating diagram

UT

I Inductive

I

Capacitive

Id UD

UT

Fig. 85: Static Synchronous Series Compensator (SSSC)

7 Concept

Operating diagram Bypass switch

8

Bank disconnect switch 1

9

Bypass circuit breaker MOV arrester

Capacitors

10

Thyristor valve

Bank disconnect switch 2

[Z]

Inadmissible area

Damping circuit

Thyristor controlled reactor

Valve arrester

Inductive Triggered spark gap

90°

Ignition angle α

Capacitive

180°

Fig. 84: Thyristor controlled Series Compensation (TCSC). Example: Single line diagram TCSC S. da Mesa

2/54

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Power Compensation in Transmission Systems

Unified Power Flow Controller (UPFC)

Concept

The Unified Power Flow Controller (UPFC) is the fastest and most versatile FACTS controller (Fig. 86). The UPFC constitutes a combination of the STATCOM and the SSSC. It can provide simultaneously and independently real time control of all basic power system parameters (transmission voltage, impedance and phase angle), determinig the transmitted real and reactive power flow to optimize line utilization and system capability. The UPFC can enhance transmission stability and dampen system oscillations.

Vector diagram

1

UT Ua

UT

Ub

2 Ua GTO Converter 1

Ub

3

GTO Converter 2

Fig. 86: Unified power-flow controller (UPFC)

4

Comparison of reactive power compensation facilities

5

The following tables show the characteristics and application areas of UPFC (Fig. 87a), parallel compensation and series compensation (Fig. 87b, page 2/56) and the influence on various parameters such as short-circuit rating, transmission phase angle and voltage behavior at this load.

6

7 Compensation element

Location

Shortcircuit level

Behavior of compensation element Voltage TransmisVoltage influence sion phase after load angle rejection

Applications

8

UPFC (Parallel and/or series compensation)

1

UPFC

Reduced E

U UPFC

Controlled

Controlled

Limited by control

Real and reactive power flow control, enhancing transmission stability and dampening system oscillations

9

10 Fig. 87a: Components for reactive power compensation, UPFC

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

2/55

Power Compensation in Transmission Systems

1

Compensation element

Location

Shortcircuit level

Behavior of compensation element Voltage TransmisVoltage influence sion phase after load angle rejection

Applications

Parallel compensation

2

2

Shunt capacitor

Little influence

Voltage rise

Little influence

High

Voltage stabilization at high load

Little influence

Voltage drop

Little influence

Low

Reactive power compensation at low load; limitation of temporary overvoltage

Little influence

Controlled

Little influence

Limited by control

Reactive power and voltage control, damping of power swings to improve system stability

No influence

Controlled

Little influence

Limited by control

Reactive power and voltage control, damping of power swings

Increased

Very good

Much smaller

(Very) low

Long transmission lines with high transmission power rating

Reduced

(Very) slight

(Much) larger

(Very) high

Short lines, limitation of SC power

Variable

Very good

Much smaller

(Very) low

Long transmission lines, power flow distribution between parallel lines and SSR damping

Reduced

Controlled

Controlled

Limited by control

Real power flow control, damping of transient oscillations

U

E

3 3

Shunt reactor

U

E

4 4

5 5

Static VAr compensator (SVC)

U

STATCOM

6

7

SVC

E

E

ST

U

Series compensation 6

Series capacitor

E

U

8 7

Series reactor

E

U

9 8

10 9

Thyristor Controlled SeriesCompensation (TCSC)

TCSC

E

U

SSSC SSSC

E

U

Fig. 87b: Components of reactive power compensation, parallel compensation/series compensation

2/56

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Switchgear Contents

Page

Introduction ...................................... 3/2 Primary Distribution Selection Criteria and Explanations ...................................... 3/4 Selection Matrix ............................... 3/6 Air-Insulated Switchgear ............... 3/8 SF6-Insulated Switchgear ............ 3/24 Secondary Distribution General ............................................. 3/46 Selection Matrix ............................. 3/48 Ring-Main Units ............................. 3/50 Consumer Substations .................. 3/60 Transformer Substations .............. 3/66 Industrial Load Center .................. 3/68 Medium-Voltage Devices Product Range ................................ 3/72 Vacuum Circuit-Breakers and Contactors ............................... 3/74 Vacuum Interrupters ..................... 3/85 Disconnectors/ Grounding Switches ...................... 3/86 HRC Fuses ....................................... 3/88 Insulators and Bushings .............. 3/89 Current Transformers/ Voltage Transformers .................... 3/90 Surge Arresters .............................. 3/90

3

Medium-Voltage Switchgear

Introduction 1

2

3

Primary and secondary distribution stands for the two basic functions of the mediumvoltage level in the distribution system. ‘Power Supply Systems’ (PSS) includes the equipment of the Primary and Secondary Distribution, all interconnecting equipment (cables, transformers, control systems, etc.) down to LV consumer distributions as well as all the relating planning, engineering, project/site management, installation and commissioning work involved, including turnkey projects with all necessary electrical and civil works equipment (Fig. 1).

4

5

6

7

8

9

10

3/2

‘Primary distribution’ means the switchgear installation in the HV/MV transformer main substations. The capacity of equipment must be sufficient to transport the electrical energy from the HV/MV transformer input (up to 63 MVA) via busbar to the outgoing distribution lines or cable feeders. The switchgear in these main substations is of high importance for the safe and flexible operation of the distribution system. It has to be very reliable during its lifetime, flexible in configuration, and easy to operate with a minimum of maintenance. The type of switchgear insulation (air or SF6) is determined by local conditions, e.g. space available, economic considerations, building costs, environmental conditions and the relative importance of maintenance. Design and configuration of the busbar are determined by the requirements of the local distribution system. These are: ■ The number of feeders is given by the outgoing lines of the system ■ The busbar configuration depends on the system (ring, feeder lines, opposite station, etc.) ■ Mode of operation under normal conditions and in case of faults ■ Reliability requirements of consumers, etc. Double busbars with longitudinal sectionalizing give the best flexibility in operation. However, for most of the operating situations, single busbars are sufficient if the distribution system has adequate redundancy (e.g. ring-type system). If there are only a few feeder lines which call for higher security, a mixed configuration is advisable. It is important to prepare enough spare feeders or at least space in order to extend the switchgear in case of further development and the need for additional feeders. As these substations, especially in densely populated areas, have to be located right in the load center, the switchgear must be space-saving and easy to install. The installation of this switchgear needs thorough planning in advance, including the system configuration and future area development. Especially where existing installations have to be upgraded, the situation of the distribution system should be analyzed for simplification (system planning and architectural system design).

‘Secondary distribution’ is the local area supply of the individual MV/LV substations or consumer connecting stations. The power capacity of MV/LV substations depends on the requirements of the LV system. To reduce the network losses, the transformer substations should be installed directly at the load centers with typical transformer ratings of 400 kVA to max. 1000 kVA. Due to the great number of stations, they must be space-saving and maintenance-free. For high availability, MV/LV substations are mostly looped in by load-break switches. The line configuration is mostly of the open-operated ring type or of radial strands with opposite switching station. In the event of a line fault, the disturbed section will be switched free and the supply is continued by the second side of the line. This calls for reliable switchgear in the substations. Such transformer substations can be prefabricated units or single components, installed in any building or rooms existing on site, consisting of medium-voltage switchgear, transformers and low-voltage distri-bution. Because of the extremely high number of units in the network, high standardization of equipment is necessary. The most economical solution for such substations should have climate-independent and maintenance-free equipment, so that operation of equipment does not require any maintenance during its lifetime. Consumers with high power requirements have mostly their own distribution system on their building area. In this case, a consumer connection station with metering is necessary. Depending on the downstream consumer system, circuit breakers or loadbreak switches have to be installed. For such transformer substations nonextensible and extensible switchgear, for instance RMUs, has been developed using SF6 gas as insulation and arc-quenching medium in the case of load-break systems (RMUs), and SF6-gas insulation and vacuum (for vcb feeders) as arc-quenching medium in the case of extensible modular switchgear, consisting of load-break panels with or without fuses, circuit-breaker panels and measuring panels.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Switchgear

1

Subtransmission up to 145 kV

Main substation

2 HV/MV transformers up to 63 MVA

3

Primary distribution MV up to 36 kV

4

5 Secondary distribution

6

7

open ring

closed ring

8 Diagram 1:

Diagram 2:

Diagram 3:

9

10

Substation

Customer station with circuit-breaker incoming panel and load-break switch outgoing panels

Extensible switchgear for substation with circuit-breakers e.g. Type 8DH

Fig. 1: Medium voltage up to 36 kV – Distribution system with two basic functions: Primary distribution and secondary distribution

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/3

Primary Distribution Selection Criteria and Explanations

General 1

Single busbar with bus-tie breaker

Double busbars with dual-feeder breakers

Double busbars with single-feeder breakers

Double-busbar switchboard with single-busbar feeders

Codes, standards and specifications

2

3

4

5

6

7

8

9

10

Design, rating, manufacture and testing of our medium-voltage switchboards is governed by international and national standards. Most applicable IEC recommendations and VDE/DIN standards apply to our products, whereby it should be noted that in Europe all national electrotechnical standards have been harmonized within the framework of the current IEC recommendations. Our major products in this section comply specifically with the following code publications: ■ IEC 60 298 AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 72.5 kV ■ IEC 60 694 Common clauses for highvoltage switchgear and controlgear standards ■ IEC 60 056 High-voltage alternating-current circuit-breakers ■ IEC 60 265-1 High-voltage switches ■ IEC 60 470 High-voltage alternating current contactors ■ IEC 60 129 Alternating current disconnectors (isolators) and grounding switches ■ IEC 60 185 Current transformers ■ IEC 60 186 Voltage transformers ■ IEC 60 282 High-voltage fuses In terms of electrical rating and testing, other national codes and specifications can be met as well, e.g. ANSI C37, 20C, BS 5227, etc. In case of switchgear manufactured outside of Germany in Siemens factories or workshops, certain local standards can also be met; for specifics please inquire. Busbar system Switchgear installations for normal service conditions are preferably equipped with single-busbar systems. These switchboards are clear in their arrangement, simple to operate, require relatively little space, and are low in inital cost and operating expenses. Double-busbar switchboards can offer advantages in the following cases: ■ Operation with asynchronous feeders ■ Feeders with different degrees of importance to maintain operation during emergency conditions ■ Isolation of consumers with shock loading from the normal network

3/4

Fig. 2: Basic basbar configurations for medium-voltage switchgear ■ Balancing of feeder on two systems dur-

ing operation ■ Access to busbars required during operation. In double-busbar switchboards with dual feeder breakers it is possible to connect consumers of less importance by singlebusbar panels. This assures the high availability of a double-busbar switchboard for important panels, e.g. incoming feeders, with the low costs and the low space requirement of a single-busbar switchboard for less important panels. These composite switchboards can be achieved with the types 8BK20 and 8DC11. Type of insulation The most common insulating medium has been air at atmospheric pressure, plus some solid dielectric materials. Under severe climatic conditions this requires precautions to be taken against internal contamination, condensation, corrosion, or reduced dielectric strength in high altitudes.

Since 1982, insulating sulfur-hexafluoride gas (SF6-gas) at slight overpressure has also been used inside totally encapsulated switchboards as insulating medium for medium voltages to totally exclude these disturbing effects. All switchgear types in this section, with the exception of the gas-insulated models 8D and NX PLUS, use air as their primary insulation medium. Ribbed vacuum-potted epoxy-resin post insulators are used as structural supports for busbars and circuit breakers throughout. In the gas-insulated metal-clad switchgear 8D and NX PLUS, all effects of the environment on high-voltage-carrying parts are eliminated. Thus, not only an extremely compact and safe, but also an exceptionally reliable piece of switchgear is available. The additional effort for encapsulating and sealing the high-voltage-carrying parts requires a higher price – at least in voltage ratings below 24 kV. For a price comparison, see the curves on the following page (Figs. 3, 4).

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Primary Distribution Selection Criteria and Explanations

Enclosure, Compartmentalization IEC Publ. 60 298 subdivides metal-enclosed switchgear and controlgear into three types: ■ Metal-clad switchgear and controlgear ■ Compartmented switchgear and controlgear ■ Cubicle switchgear and controlgear. Thus “metal-clad” and “cubicle” are subdivisions of metal-enclosed switchgear, further describing construction details. In metal-clad switchgear the components are arranged in 3 separate compartments: ■ Busbar compartment ■ Circuit-breaker compartment ■ Feeder-circuit compartment with earthed metal partitions between each compartment. IEC 60 298-1990-12 Annex AA specifies a “Method for testing the metal-enclosed switchgear and controlgear under conditions of arcing due to an internal fault”. Basically, the purpose of this test is to show that persons standing in front of, or adjacent to a switchboard during internal arcing are not endangered by the effects of such arcs. All switchboards described in this section have successfully passed these type tests. Isolating method To perform maintenance operations safely, one of two basic precautions must be taken before grounding and short-circuiting the feeder: ■ 1. Opening of an isolator switch with clear indication of the OPEN condition. ■ 2. Withdrawal of the interrupter carrier from the operating into the isolation position. In both cases, the isolation gap must be larger than the sparkover distance from live parts to ground to avoid sparkover of incoming overvoltages across the gap. The first method is commonly found in fixed-mounted interrupter switchgear, whereas the second method is applied in withdrawable switchgear. Withdrawable switchgear has primarily been designed to provide a safe environment for maintenance work on circuit interrupters and instrument transformers. Therefore, if interrupters and instrument transformers are available that do not require maintenance during their lifetime, the withdrawable feature becomes obsolete. With the introduction of maintenance-free vacuum circuit-breaker bottles, and instrument transformers which are not subject

Single busbar

Double busbar

! Percentage (8BK20 = 100)

! Percentage (8BK20 = 100)

160

160

130 120 110 100 90 80 70 0

120 8DA10 NX PLUS 110 100 8BK20 90 NX AIR 80 8DC11 70

1

130

7.2

12

15 24 kV

36 Voltage

0

2 8BK20 8DB10 8DC11 7.2

12

15 24 kV

36 Voltage

Fig. 3: Price relation

Fig. 4: Price relation

to dielectric stressing by high voltage, it is possible and safe to utilize totally enclosed, fixed-mounted and gas-insulated switchgear. Models 8DA, 8DB, 8DC and NX PLUS described in this section are of this design. Due to far fewer moving parts and their total shielding from the environment, they have proved to be much more reliable. All air-insulated switchgear models in this section are of the withdrawable type.

able in all ratings – see selection matrix on pages 3/72–3/73 for all power switchgear listed in this section. Due to their maintenance-free design these breakers can be installed inside totally enclosed and gasinsulated switchgear.

Switching device Depending on the switching duty in individual switchboards and feeders, basically the following types of primary switching devices are used in the switchgear cubicles in this section: (Note: Not all types of switching devices can be used in all types of cubicle.)

■ 1. Vacuum circuit-breakers ■ 2. Vacuum contactors in conjunction

with HRC fuses ■ 3. Vacuum switches, switch disconnec-

tors or gas-insulated three-position switch disconnectors in conjunction with HRC fuses. To 1: Vacuum circuit-breakers In the continuing efforts for safer and more reliable medium-voltage circuit-breakers, the vacuum interrupter is clearly the first choice of buyers of new circuit-breakers worldwide. It is maintenancefree up to 10,000 operating cycles without any limitation in terms of time and it is recommended for all generalpurpose applications. If high numbers of switching operations are anticipated (especially autoreclosing in overhead line systems and switching of high-voltage motors), their use is indicated. They are avail-

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3

4

5

To 2: Vacuum contactors Vacuum contactors are used for frequent switching operations in motor, transformer and capacitor bank feeders. They are typetested, extremely reliable and compact devices and they are totally maintenance-free. Since contactors cannot interrupt fault currents, they must always be used with current-limiting fuses to protect the equipment connected. Vacuum contactors can be installed in the metal-enclosed, metalclad switchgear types 8BK20, 8BK30 and NXAIR for 7.2 kV/31.5 kA. To 3: Vacuum switches or … Vacuum switches, switch disconnectors and gas-insulated three-position switch disconnectors in primary distribution switchboards are used mostly for small transformer feeders such as auxiliary transformers or load center substations. Because of their inability to interrupt fault currents they must always be used with currentlimiting fuses. Vacuum switches and switch disconnectors can be installed in the airinsulated switchboard types 8BK20 and NXAIR. Gas-insulated three-position switch disconnectors can be installed in the switchboard type 8DC11.

For further information please contact: ++ 49 - 91 31-73 46 39

3/5

6

7

8

9

10

Primary Distribution Selection Matrix

1

Standards

Insulation

Busbar system

Enclosure, compartmentalization

Isolating method

Sw de

2 Metal-enclosed, metal-clad

Draw-out section

Metal-enclosed, metal-clad

Draw-out section

Vac

Metal-enclosed, metal-clad

Draw-out section

Vac

Metal-enclosed, metal-clad cubicle-type

Draw-out section

Vac Vac Sw Vac

Metal-enclosed, metal-clad

Draw-out section

Vac Vac

Metal-enclosed, metal-clad cubicle-type

Draw-out section

Vac Vac Sw

Triple-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Vac

Triple-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Vac Sw

Single-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Vac

Triple-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Vac Sw

Single-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Vac

Vac Vac

3 Single busbar

4 Type-tested indoor switchgear to IEC 60 298

Air-insulated

5

6

Double busbar

7

8 Single busbar

9 SF6-insulated

10 Double busbar

Fig. 5: Primary Distribution Selection Matrix

3/6

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Primary Distribution Selection Matrix

Switching device

Vacuum circuit-breaker Vacuum switch

Switchgear type

8BK20

Technical data

Page

Maximum rated short-time current [kA], 1/3 s

Maximum busbar rated current [A]

Maximum feeder rated current [A]

7.2 kV

7.2 kV

7.2 kV

50

12/15 17.5/24 36 kV kV kV

50

25

–

12/15 17.5/24 36 kV kV kV

4000 4000

2500

–

4000

12/15 17.5/24 36 kV kV kV

4000

2000

–

1

2 3/8

3 Vacuum contactor

8BK30

50

50

–

–

4000 4000

–

–

400

400

–

–

3/13

8BK40

63

63

63*

–

5000 5000

5000*

–

5000

5000

5000*

–

3/16

Vacuum circuit-breaker Vacuum switch Switch disconnector Vacuum contactor

NXAIR

31.5

31.5

25

–

2500 2500

2500

–

2500

2500

2500

–

3/20

5

Vacuum circuit-breaker Vacuum switch

8BK20

50

50

25

–

4000 4000

2500

–

4000

4000

2000

–

3/8

6

Vacuum circuit-breaker Vacuum switch Switch disconnector

NXAIR

31.5

31.5

25

–

2500 2500

2500

–

2500

2500

2500

–

3/20

4

Vacuumcircuit-breaker

7

Vacuum circuit-breaker

NX PLUS

31.5

31.5

31.5

31.5

2500 2500

2500

2500

2500

2500

2500 2500

3/38

8 Vacuum circuit-breaker Switch disconnector

3/24

8DC11

25

25

25

–

1250 1250

1250

–

1250

1250

1250

8DA10

40

40

40

40

3150 3150

3150

2500

2500

2500

2500 2500

3/30

8DC11

25

25

25

–

1250 1250

1250

–

1250

1250

1250

3/24

8DB10

40

40

40

40

3150 3150

3150

2500

2500

2500

2500 2500

–

9

Vacuum circuit-breaker

Vacuum circuit-breaker Switch disconnector

–

Vacuumcircuit-breaker 3/30

* up to 17.5 kV

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/7

10

Air-Insulated Switchgear Type 8BK20

1

Metal-clad switchgear 8BK20, air-insulated ■ From 7.2 to 24 kV ■ Single and double-busbar

2

3

■ ■ ■ ■ ■ ■ ■

(back-to-back or face-to-face) Air-insulated Type-tested Metal-enclosed Metal-clad Withdrawable vacuum breaker Vacuum switch optional For indoor installation

Specific features

4

■ General-purpose switchgear ■ Circuit-breaker mounted on horizontal

slide behind front door ■ Cable connections from front or rear

5

Safety for operating and maintenance personnel ■ All switching operations behind closed

doors ■ Positive and robust mechanical

6

interlocks ■ Arc-fault-tested metal enclosure ■ Complete protection against contact

7

with live parts ■ Line test with breaker inserted (option) ■ Maintenance-free vacuum breaker Tolerance to environment

8

■ Metal enclosure with optional gaskets ■ Complete corrosion protection and

tropicalization of all parts. ■ Vacuum-potted ribbed epoxy insulators

with high tracking resistance

9

10

General description 8BK20 switchboards consist of metal-clad cubicles of air-insulated switchgear with withdrawable vacuum circuit-breakers. Fused vacuum switches can be used optionally. The breaker carriage is fully interlocked with the interrupter and the stationary cubicle. It is manually moved in a horizontal direction from the ”Connected“ position behind the closed front door and without the use of auxiliary equipment. A fully isolated low-voltage compartment is integrated. All commonly used feeder circuits and auxiliary devices are available. The switchgear cubicles and interrupters are factory-assembled and type-tested as per the applicable standards.

3/8

Fig. 6: Metal-clad switchgear type 8BK20 (inter-cubicle partition removed)

Stationary part

Breaker carriage

The cubicle is built as a self-supporting structure, bolted together from rolled galvanized steel sheets and profile sections. Each cubicle is divided into three sealed and isolated compartments by partitions, i.e. the busbar, cable connection and circuitbreaker compartment. The fixed contacts of the primary disconnectors are located within bushings, effectively maintaining the compartmentalization in all operating states of the switchgear. The bushings are covered by automatic steel safety shutters upon removal of the circuit-breaker carriage from the ”Connected“ position. Each compartment in every model has its own pressure-relief device. To reduce internal arcing times and thus consequential damage, pressure switches can be installed that trip the incoming feeder circuitbreaker(s) in less than 100 msec. This is an economical alternative to busbar differential protection.

The carriage normally supports a vacuum circuit-breaker with the associated operating mechanism and auxiliary devices. Fused vacuum switches are optional. By manually moving the carriage with the spindle drive it can be brought into a distinct ”Connected“ and ”Disconnected/ Test“ position. To this effect, the arc and pressure-proof front door remains closed. To remove the switching element completely from its compartment, a central service truck is used. Inspection can easily and safely be carried out with the circuitbreaker in the ”Disconnected/Test“ position. All electrical and mechanical parts are easily accessible in this position. Mechanical spring-charge and contactposition indicators are visible through the closed door. Local mechanical ON/OFF pushbuttons are actived through the door as well. For complete remote control, the circuitbreaker carriage can be equipped for motor operation.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Air-Insulated Switchgear Type 8BK20

Cable and bar connections

Fig. 7: Cross-section through 8BK20 cubicle

Low-voltage compartment

Busbars and primary disconnectors

All protective relays, monitoring and control devices of a feeder can be accommodated in a metal-enclosed LV compartment on top of the HV enclosure. Device-mounting plates, cabling troughs, and the central LV terminal strip(s) are located behind a separate lockable door. Full or partial plexiglass windows, or mimic diagrams are available for these doors.

Rectangular busbars drawn from pure copper are used exclusively. They are mounted on ribbed, cast-resin post insulators which are sized to take up the dynamic forces resulting from short circuits. Soliddielectric busbar insulation is available. The movable parts of the line and loadside primary disconnectors have flat, spring-loaded and silver-plated hemispherical pressure contacts for low contact resistance and good ventilation. The parallel connecting arms are designed to increase contact pressure during short circuits. The fixed contacts are silver-plated stubs within the circuit-breaker bushings or the busbar mountings.

Main enclosure The totally enclosed and sealed cubicle permits installation in most equipment rooms. With the optional dust protection, the switchgear is safeguarded against internal contamination, small animals and rodents, and naturally against contact with live parts. This eliminates the usual reasons for arc faults. Should arcing occur, nevertheless, the arc can be guided towards the end of the lineup, where damage is repaired most easily. For the latter reason, parititions between individual cubicles of the same bus sections are normally not used.

Cables and bars are connected from below; entrance from above requires an auxiliary structure behind the cubicle. Single-phase or three-phase solid-dielectric cables can be connected from the front or the rear of the cubicle (specify); stress cones are installed conveniently inside the cubicle. Make-proof grounding switches with manual operation can be installed below the CTs, engaging contacts behind the cable lugs. Operation of the fully interlocked grounding switch is possible only with the breaker carriage in the ”Disconnected/ Test“ position.

1

Interlocking system

4

A series of sturdy mechanical interlocks forces the operator into the only safe operating sequence of the switchgear, preventing positively the following: ■ Moving the carriage with the breaker closed. ■ Switching the breaker in any but the locked ”Connected“ or ”Disconnected/ Test“ position ■ Engaging the grounding switch with the carriage in the ”Connected“ position, and moving the carriage into this position with the grounding switch engaged.

2

3

5

6

Degrees of protection Standard degree of protection IP 3XD according to IEC 60529. Optionally, the cubicles can be protected against harmful internal deposits of dust and against dripping water (IP 51), available only for cubicles without ventilation slots.

7

8

9

Instrument transformers Up to three multicore block-type current transformers plus three single-phase potential transformers can be installed in the lower compartment, PTs optionally on withdrawable modules. The CTs carry the cable-connecting bars and lugs, and the fixed contacts of the (optional) grounding switch. All common burden and accuracy ratings of instrument transformers are available. Busbar metering PTs with their current-limiting fuses are installed on withdrawable carriages, identically to breaker carriages.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

10

3/9

Air-Insulated Switchgear Type 8BK20

Installation

1

2

3

4

The switchboards are shipped in sections of up to three cubicles on stable wooden pallets which are suitable for rolling and forklift handling. These sections are bolted or spot-welded to channel iron sections embedded in a flat and level concrete floor. Front-connected types can be installed against the wall or free-standing; rear-connected cubicles require service aisles. Double-busbar installations in back-to-back configuration are installed free-standing. Cable feed-in is through corresponding cut-outs in the floor, plans for which are part of the switchgear supply. Three-phase (armored) cables for voltages above 12 kV require sufficient clearance below the switchgear to split up the phases (cablefloor, etc.). Circuit-breakers are shipped mounted on their carriages inside the switchgear cubicles. For dimensions and weights, see Fig. 9.

5

Fig. 8: Cross-section through switchgear type 8BK20 in back-to-back double-busbar arrangement for rated voltages up to 24 kV

Weights and dimensions

6

7

8

Rated voltage

[kV]

7.2

12

15

17.5

24

Panel spacing

[mm]

800

800

800

1000

1000

Width

[mm]

2050

2050

2050

2250

2250

Depth front conn. without channel with channel

[mm] [mm]

1650 1775

1650 1775

1650 1775

2025 2150

2025 2150

Depth rear conn.

[mm]

1775

1775

1775

2150

2150

Approx. weight incl. breaker

[kg]

800

800

800

1000

1000

Fig. 9

9

10

3/10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Air-Insulated Switchgear Type 8BK20

1

Technical data Rated lightning impulse voltage

Rated shorttime power frequency voltage

Rated shortcircuit-breaking current/shorttime current (1 or 3 s available)

Rated shortcircuit making current

[kV]

[kV]

[kV]

[kA] (rms)

[kA]

7.2

60

20

31.5 40* 50*

80 110 125

– – –

■ ■ ■

■ ■ –

■ ■ ■

– ■ ■

– ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

12

75

28

31.5 40* 50*

80 110 125

– – –

■ ■ ■

■ ■ –

■ ■ ■

– ■ ■

– ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

15

95

36

31.5 40* 50*

80 110 125

– – –

■ ■ ■

■ ■ –

■ ■ ■

– ■ ■

– ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

5

17.5

95

38

16 20 25

40 50 63

■ ■ ■

■ ■ ■

– – ■

– – –

– – –

– – –

■ ■ ■

■ ■ ■

■ ■ ■

– – –

– – –

6

125

50

16 20 25

40 50 63

■ ■ –

■ ■ ■

– ■ ■

– – –

– – –

– – –

■ ■ ■

■ ■ ■

■ ■ ■

– – –

– – –

Rated voltage

24

Rated normal feeder current*

Rated normal busbar current

2 630 1250 2000 2500 3150 4000 1) [A] [A] [A] [A] [A] [A]

1250 2000 2500 3150 4000 [A] [A] [A] [A] [A]

3

4

7

*1s 1) Ventilation unit with or without fan and ventilation slots in the front of the cubicle required.

8

Fig. 10

9

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/11

Air-Insulated Switchgear Type 8BK20

1

8BK20 switchgear up to 24 kV Panel Fixed parts

2

Withdrawableparts

Busbar modules

Sectionalizer

Bus riser panel

Metering Busbar connecpanel tion panel

3

4

5

6

Fig. 11: Available circuit options

7

8

9

10

3/12

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Air-Insulated Switchgear Type 8BK30

Vacuum contactor motor starters 8BK30, air-insulated

1

From 3.6–12 kV Single-busbar Type-tested Metal-enclosed Metal-clad Withdrawable vacuum contactors and HRC current-limiting fuses ■ For direct lineup with 8BK20 switchgear ■ For indoor installation ■ ■ ■ ■ ■ ■

2

3

Specific features

4

■ Designed as extension to 8BK20 switch■ ■ ■ ■

gear with identical cross section Contactor mounted on horizontally moving truck – 400 mm panel spacing Cable connection from front or rear Central or individual control power transformer Integrally-mounted electronic multifunction motor-protection relays available.

5

6

Safety of operating and maintenance personnel ■ All switching operations behind closed

doors ■ Positive and robust mechanical inter-

7

locks ■ Arc-fault-tested metal enclosure ■ Complete protection against contact

with live parts ■ Absolutely safe fuse replacement ■ Maintenance-free vacuum interrupter

8

tubes Tolerance to environment ■ Metal enclosure with optional gaskets ■ Complete corrosion protection and tropi-

calization of all parts ■ Vacuum-potted ribbed expoy insulators with high tracking resistance

Fig. 12: Metal-clad switchgear type 8BK30 with vacuum contactor (inter-cubicle partition removed)

9

Technical data Rated voltage

BIL

PFWV

Maximum rating of motor

Feeder rating

Rated busbar current

10

[kV]

[kV]

[kV]

[kW]

[A]

1250 [A]

3.6 7.2 12

40 60 60

10 20 28

1000 2000 3000

400 400 400

■ ■ ■

2000 [A]

2500 [A]

3150 [A]

4000 [A]

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

Fig. 13

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/13

Air-Insulated Switchgear Type 8BK30

1

Full-voltage nonreversing (FVNR)

Reduced-voltage nonreversing (RVNR) with starter (reactor starting)

Reduced-voltage nonreversing (RVNR) with external reactor autotransformer ”Korndorffer Method“

2

3

4

5

Fig. 14: Available circuits

6

7

8

9

General description

The stationary part

Busbars and primary disconnectors

8BK30 motor starters consist of metalenclosed, air-insulated and metal-clad cubicles. Vacuum contactors on withdrawable trucks, with or without control power transformers, are used in conjunction with current-limiting fuses as starter devices. The truck is fully interlocked with the structure and is manually moved from the ”Connected“ to the ”Disconnected/Test“ position. A fully isolated low-voltage compartment is integrated. All commonly used starter circuits and auxiliary devices are available. The starter cubicles and contactors are factory-assembled and type-tested as per applicable standards.

The cubicle is constructed basically the same as the matching switchgear cubicles 8BK20, with the exception of the contactor truck.

Horizontal busbars are identical to the ones in the associated 8BK20 switchgear. Primary disconnectors are adapted to the low feeder fault currents of these starters. Silver-plated tulip contacts with round contact rods are used.

10

Contactor truck Vacuum contactor, HRC fuses, and control power transformer with fuses (if ordered) are mounted on the withdrawable truck. Auxiliary devices and interlocking components, plus the primary disconnects complete the assembly. Low-voltage compartment Space is provided for regular bimetallic or electronic motor-protection relays, plus the usual auxiliary relays for starter control. The compartment is metal-enclosed and has its own lockable door. All customer wiring is terminated on a central terminal strip within this compartment.

CTs and cable connection Due to the limited let-through current of the HRC fuse, block-type CTs with lower thermal rating can be used. Depending on the protection scheme used, CTs with one or two secondary windings are installed. All commonly used feeder cables up to 300 mm2 can be terminated and connected at the lower CT terminals. Grounding switches or surge-voltage limiters are installed optionally below the current transformers.

Main enclosure Practically identical to the associated 8BK20 switchgear.

3/14

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Air-Insulated Switchgear Type 8BK30

Interlocking system Contactor, truck and low-voltage plugs are integrated into the interlocking system to assure the following safeguards: ■ The truck cannot be moved into the ”Connected“ position before the LV plug is inserted. ■ The LV plug cannot be disconnected with the truck in the ”Connected“ position. ■ The truck cannot be moved with the contactor in the ON position. ■ The contactor cannot be operated with the truck in any other but the locked ”Connected“ or ”Disconnected/Test“ position. ■ The truck cannot be brought into the ”Connected“ position with the grounding switch engaged. ■ The grounding switch cannot be engaged with the truck in the ”Connected“ position.

1

2

3

4

5

Degrees of protection Standard degree of protection IP 3XD according to IEC 60529. Optionally, the starters can be protected against harmful internal deposits of dust and against dripping water in the ”Operating“ position (IP 51).

6 Fig. 15: Cross-section through switchgear type 8BK30

Installation Identical to the procedures outlined for 8BK20 switchgear. Only the HRC fuses are shipped outside the enclosure, separately packed.

7

Weights and dimensions Rated voltage

[kV]

Width

3.6

7.2

12

[mm]

2 x 400

2 x 400

2 x 400

Height

[mm]

2050

2050

2050

Depth

[mm]

1650

1650

1650

Approx. weight incl. contactor

[kg]

700

700

700

8

9

Fig. 16

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/15

Air-Insulated Switchgear Type 8BK40

1

Metal-clad switchgear 8BK40, air-insulated ■ From 7.2 to 17.5 kV ■ Single and double-busbar

2

3

■ ■ ■ ■ ■ ■

(back-to-back or face-to-face) Air-insulated Type-tested Metal-enclosed Metal-clad Withdrawable vacuum breaker For indoor installation

Specific features ■ General-purpose switchgear for rated

4

5

feeder/busbar current up to 5000 A and short-circuit breaking current up to 63 kA ■ Circuit-breaker mounted on horizontally moving truck ■ Cable connections from front Safety of operating and maintenance personnel ■ All switching operations behind closed

6

■ ■

7

■ ■

doors Positive and robust mechanical interlocks Complete protection against contact with live parts Line test with breaker inserted (option) Maintenance-free vacuum circuitbreaker

Fig. 17: Metal-clad switchgear type 8BK40 with vacuum circuit-breaker 3AH (inter-cubicle partition removed)

Tolerance to environment

8

■ Sealed metal enclosure with optional

gaskets ■ Complete corrosion protection and tropi-

calization of all parts ■ Vacuum-potted ribbed epoxy-insulators

9

with high tracking resistance Generator vacuum circuit-breaker panel ■ Suitable for use in steam, gas-turbine,

hydro and pumped-storage power plants

10

■ Suitable for use in horizontal, L-shaped

or vertical generator lead routing

Fig. 18: Cross-section through type 8BK40 generator panel

3/16

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Air-Insulated Switchgear Type 8BK40

General description 8BK40 switchboards consist of metal-clad cubicles of air-insulated switchgear with withdrawable vacuum circuit-breakers. The breaker truck is fully interlocked with the interrupter and the stationary cubicle. It is manually moved in a horizontal direction from the ”Connected“ position behind the closed front door and without the use of auxiliary equipment. A fully isolated lowvoltage compartment is integrated. All commonly used feeder circuits and auxiliary devices are available. The switchgear cubicles and interrupters are factory-assembled and type-tested as per applicable standards.

1

Stationary part

4

The cubicle is built as a self-supporting structure, bolted together from rolled galvanized steel sheets and profile sections. Cubicles for rated voltages up to 17.5 kV are of identical construction. Each cubicle is divided into three sealed and isolated compartments by partitions, i.e. the busbar, cable connection and circuit-breaker compartment. The fixed contacts of the primary disconnectors are located within insulating breaker bushings, effectively maintaining the compartmentalization in all operating states of the switchgear. The bushings are covered by automatic steel safety shutters upon removal of the circuit-breaker element from the ”Connected“ position. Each compartment in every model has its own pressure-relief device. To reduce internal arcing times and thus consequential damage, pressure-switches can be installed that trip the incoming-feeder circuit-breaker(s) in less than 100 msec. This is an economic alternative to busbar differential protection. Interrupter truck The truck normally supports a vacuum circuit-breaker with the associated operating mechanism and auxiliary devices. By manually moving the truck with the spindle drive it can be brought into a distinct ”Connected“ and ”Disconnected/ Test“ position. To this effect, the front door remains closed. Inspection can easily and safely be carried out with the circuit-breaker in the ”Disconnected/Test“ position. All electrical and mechanical parts are easily accessible in this position. Mechanical spring-charge and contact-posi-

2

3

5

Fig. 19: Cross-section through panel type 8BK40

tion indicators are visible through the closed door. Local mechanical ON/OFF pushbuttons are actived through the door as well. For complete remote control, the circuitbreaker carriage can be equipped for motor operation. Low-voltage compartment All protective relays, monitoring and control devices of a feeder can be accommodated in a metal-enclosed LV compartment on top of the HV enclosure. Device-mounting plates, cabling troughs, and the central LV terminal strip(s) are located behind a separate lockable door. Full or partial plexiglass windows, or mimic diagrams are available for these doors. Main enclosure The totally enclosed and sealed cubicle permits installation in most equipment rooms. With the optional dust protection, the switchgear is safeguarded against internal contamination, small animals and rodents, and naturally against contact with live parts. This eliminates the usual reasons for arc faults. Should arcing occur, nevertheless, the arc can be guided

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

6 towards the end of the lineup, where damage is repaired most easily. For the latter reason, partitions between individual cubicles of the same bus sections are normally not used.

7

Busbars and primary disconnectors Rectangular busbars drawn from pure copper are used exclusively. They are mounted on ribbed, cast-resin post insulators which are sized to take up the dynamic forces resulting from short circuits. The movable parts of the line and loadside primary disconnectors have flat, spring-loaded and silver-plated hemispherical pressure contacts for low contact resistance and good ventilation. The parallel connecting arms are designed to increase contact pressure during short circuits. The fixed contacts are silver-plated stubs within the circuit-breaker bushings. Instrument transformers Up to three multicore block-type current transformers plus three single-phase potential transformers can be installed in the lower compartment, PTs optionally on withdrawable modules.

3/17

8

9

10

Air-Insulated Switchgear Type 8BK40

1

2

The CTs carry the cable-connecting bars and lugs, and the fixed contacts of the (optional) grounding switch. All common burden and accuracy ratings of instrument transformers are available. Busbar metering PTs with their current-limiting fuses are installed on a withdrawable truck, identical to the breaker truck. Cable and bar connections

3

4

5

Cables and bars are connected from below; entrance from above requires an auxiliary structure behind the cubicle. Single-phase or three-phase solid-dielectric cables can be connected from the front of the cubicle; stress cones are installed conveniently inside the cubicle. Regular and make-proof grounding switches with manual operation can be installed below the CTs, engaging contacts behind the cable lugs. Operation of the fully interlocked grounding switch is possible only with the breaker carriage in the ”Disconnected/Test“ position.

Weight and dimensions 7.2

12

15

17.5

[mm]

1100

1100

1100

1100

Height

[mm]

2500

2500

2500

2500

Depth

[mm]

2300

2300

2300

2300

Approx. weight incl. breaker

[kg]

2800

2800

2800

2800

Rated voltage

[kV]

Width

Fig. 20

Technical data Rated voltage

Rated lightningimpulse voltage

Rated short-time powerfrequency voltage

Rated shortcircuitbreaking current/ short time current

Rated shortcircuitmaking current

[kV]

[kV]

kA [rms]

[kA]

7.2

60

20

50 63

125 160

12

75

28

50 63

125 160

15

95

36

50 63

125 160

17.5

95

38

50 63

125 160

Interlocking system

6

7

8

A series of sturdy mechanical interlocks forces the operator into the only safe operating sequence of the switchgear, preventing positively the following: ■ Moving the truck with the breaker closed. ■ Switching the breaker in any but the locked ”Connected“ or ”Disconnected/ Test“ position. ■ Engaging the grounding switch with the truck in the ”Connected“ position, and moving the truck into this position with the grounding switch engaged.

[kV]

Rated normal feeder current

1250 2500 3150 5000 [A] [A] [A] [A]

Rated normal busbar current

5000 [A]

Degrees of protection

9

10

Degree of protection IP 4X: In the ”Connected“ and the ”Disconnected/Test“ position of the truck, the switchgear is totally protected against contact with live parts by objects larger than 2 mm in diameter. Optionally, the cubicles can be protected against harmful internal deposits of dust and against drip water (IP 51). Installation The switchboards are shipped in sections of one cubicle on stable wooden pallets which are suitable for rolling and forklift handling. These sections are bolted or spot-welded to channel iron sections embedded in a flat and level concrete floor.

3/18

Fig. 21

Front-connected types can be installed against the wall or free-standing. Doublebusbar installations in back-to-back configuration are installed free-standing. Cable feed-in is through corresponding cutouts in the floor; plans for which are part of the switchgear scope of supply. Threephase (armored) cables for voltages above 12 kV require sufficient clearance below the switchgear to split up the phases (cable floor, etc.). Circuit-breakers are shipped mounted on their trucks inside the switchgear cubicles. For preliminary dimensions and weights, see Fig. 20.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Air-Insulated Switchgear Type 8BK40

1

8BK40 switchgear up to 17.5 kV

Panel Fixed parts

Withdraw- Metering Busbar modules ableparts panel

Sectionalizer

2

Bus riser panel

3

4

5

6 8BK40 generator vacuum CB panel

7 Variants

Additional parts

Optional parts

8

9

10

Fig. 22: Available circuit options for switchgear/generator panel type 8BK40

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/19

Air-Insulated Switchgear Type NXAIR

1

Renewed availability

Metal-clad or cubicle type switchgear NXAIR, air-insulated

■ Internal fault withstand capability satis-

fied according to standards ■ Separate pressure relief for every com-

partment

■ From 3.6 to 24 kV ■ Single- and double-busbar (back to back

2

3

■ Standard direction of pressure relief

upwards

or face-to-face) Air-insulated Metal-enclosed Metal-clad or cubicle type Modular construction of individual panels Supplied as standard with bushingtype transformers for selective tripping of feeders without any additional measures. ■ Vacuum circuit-breaker module type NXACT

■ Busbar fittings (e.g. voltage transform-

■ ■ ■ ■ ■

■

■ ■

4

■

Specific features ■ General-purpose switchgear ■ Circuit-breaker mounted on horizontal

5

■

slide or truck behind front door ■ Cable connections from front or rear ■

Safety of operating and maintenance personnel

6

doors ■ Switchgear modules with intgrated inter■

7

■ ■

8

■

■ All switching operations behind closed

ers, current transformers in run of busbar or make-proof earthing switches) arranged in separate compartments above busbar compartments Pressure-resistant additional compartments with pressure-proof barrier to busbar compartment Pressure-resistant floor covering Control cables inside panels arranged in metallic cable ducts Cable testing without isolation of busbar assured by separately opening shutters of module compartment Easy replacement of compartments by virtue of self-supporting, modular and bolted construction Replacement of module compartments and/or connection compartments possible without having to isolate busbar Bushing-type transformers for selective disconnection of feeders

■ ■

9

10

■

locking and control board Panels tested for internal arcs to IEC 60 298, App. AA Complete protection against contact with live parts Mechanical switch position indication on panel front for switching device, disconnector and earthing switch Earthing of feeders by means of makeproof earthing switches. Operation of all switching, disconnecting and earthing functions from panel front – Unambiguous assignment of actuating openings and control elements to mechanical switch position indications – Mechanical switch position indications integrated in mimic diagram – Convenient height of actuating openings, control elements and mechanical switch position indications on highvoltage door, as well as low-voltage unit in door of low-voltage compartment. – Logical interlocks prevent maloperation Option: verification of dead state with high-voltage door closed, by means of a voltage detection system according to IEC 61 243-5

3/20

Fig. 23: Metal-clad switchgear type NXAIR

Standards ■ The switchgear cubicles and interrupters

are factory assembled and type-tested according to VDE 0670 Part 6 and IEC 60 298.

Flexibility ■ Wall mounting or free-standing arrange-

ment ■ Cable connection from front or rear ■ Connection of all familiar types of cables ■ Available in truck-type or withdrawable

construction ■ Optional left or right-hand arrangement

■ ■ ■

■

of hinges – of high-voltage doors – of doors of low-voltage compartments Extension of existing switchgear at both ends without modification of panels Easy replacement of bushing-type transformers from front Screw-type mating contacts on bushingtype transformers can be easily replaced from front (from module compartment). Reconnection of current transformers on secondary side

Degrees of protection Standard degree of protection IP3XD according to IEC 60 529 Optionally, the cubicles can be protected against harmful internal deposits of dust and against dripping water (IP 51), available only for cubicles without ventilation slots.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Air-Insulated Switchgear Type NXAIR

NXAIR is of modular construction. The main components are: A Module compartment B Busbar compartment C Connection compartment D NXACT vacuum circuit-breaker module E Low-voltage compartment Module compartment Basic features ■ Housings are of sendzimir-galvanized ■ ■

■ ■ ■ ■ ■

sheet-steel High-voltage door and front frame with additional epoxy resin powder coating Module compartment to accomodate necessary components (vacuum circuitbreaker module, vacuum contactor module, disconnector module, metering module and transformer feeder module) for implementing various panel versions With shutter operating mechanism High-voltage door pressure-proof in event of internal arcs in panel Metallic cable ducts on side for laying control cables (internal and external) Option: test sockets for capactive voltage detection system Low-voltage plug connectors for connection of switchgear modules to auxiliary voltage circuits.

NXACT vacuum circuit-breaker module Features ■ Integrated mechanical interlocks be-

tween operating mechanisms ■ Integrated mechanical switch position

indications for circuit-breaker, withdrawable part and earthing switch functions ■ Easy movement since only withdrawable part is moved ■ Permanent interlock of carriage mechanism of switchgear module in panel Low-voltage compartment

1

E

B

2

1 2 3 4 5 6

A

3

9

4

10 D

5

12

6 7

11

7 8 9 10 11

C

8

13 14

12 13 14

Pressure relief duct Busbars Bushing-type insulator Bushing-type transformer Make-proof earthing switch Cable connection for 2 cables per phase Cables Cable brackets Withdrawable part Vacuum interrupters Combined operating and interlocking unit for circuitbreaker, disconnector and earthing switch Contact system Earthing busbar Option: truck

1

2

3

4

Fig. 24: Cross-section through cubicle type NXAIR

Solid-state HMI (human-machine interface) Bay controller SIPROTEC 4 type 7SJ62 for control and protection (Fig.25)

5 Door of low-voltage compartment

6

Features 1 LCD for process and equipment data, e.g. for: – Measuring and metering values – Binary data for status of switchpanel and device – Protection data – General signals – Alarm 2 Keys for navigation in menus and for entering values 3 Seven programmable LEDs with possible application-related inscriptions, for indicating any desired process and equipment data 4 Four programmable function keys for frequently performed actions.

7

8

9

1 2

■ Accommodates equipment for protec-

■ ■

■ ■

tion, control, measuring and metering, e.g. bay controller SIPROTEC 4 type 7SJ62 Shock-protected from high-voltage section by barriers Low-voltage compartment can be removed; ring and control cables are plugged in Option: low-voltage compartment of increased height (980 mm) possible Option: partition wall between panels.

3

10

4

Bay controller SIPROTEC 4 type 7SJ62 Fig. 25: Bay controller

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/21

Air-Insulated Switchgear Type NXAIR

1

2

3

4

5

6

Technical data Rated voltage

[kV]

12

15

17.5

24

Rated short-time power-frequency voltage

[kV]

28 1)

36

38

50

Rated lightning impulse voltage

[kV]

75

95

95

125

Rated short-circuit breaking current max. [kA]

31.5

31.5

25

25

Rated short-time withstand current

31.5

31.5

25

25

80

80

63

63

max. [kA]

Rated short-circuit making current max. [kA] Rated normal current of busbar

max. [A]

2500

2500

2500

2500

Rated normal current of feeder

max. [A]

2500

2500

2500

2500

Rated normal current of transformer feeder panels with HV HRC fuses 2)

Depends on rated current of fuse used

1) 42 kV on request 2) At 7.2 kV: max. rated current 250 A at 12 kV: max rated current 150 A at 15/17.5/24 kV: max. rated current 100 A

7

Fig. 26

Weights and dimensions

8

9

Width

[mm]

800

800

800

800*) / 1000

Height

[mm]

2000

2300

2300

2300

Height with high LV compartment

[mm]

2350

2650

2650

2650

Depth

[mm]

1350

1550

1550

1550

Weight (approx.)

[kg]

600

*) up to 1250 A rated normal current of feeder

10

Fig. 27

3/22

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Air-Insulated Switchgear Type NXAIR

Incoming and outgoing feeder panel with circuitbreaker module

Outgoing feeder panel with disconnector module

Metering panel with metering module

Transformer feeder panel with transformer feeder module and fuses

1

2

3

4 Switch disconnector panel

Sectionalizer panel of the bus sectionalizer

Bus riser panel of the bus sectionalizer

Spur panel with circuit-breaker module

5

6

7 Feeder panel with busbar current metering

Feeder panel with busbar earthing switch

Feeder panel with busbar connection

Feeder panel with busbar voltage metering

(optional)*

(optional)*

(optional)*

(optional)*

8

9

10

Components shown with dashes are optional * Not for feeder panels with open-circuit ventilation, busbar current metering up to 12 kV, 25 kA Fig. 28: Available circuit options

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/23

SF6-Insulated Switchgear Type 8DC11

1

2

Gas-insulated switchgear type 8DC11 ■ ■ ■ ■ ■ ■

3

■ ■ ■

4 ■

From 3.6 up to 24 kV Triple-pole primary enclosure SF6-insulated Vacuum circuit-breakers, fixed-mounted Hermetically-sealed, welded, stainlesssteel switchgear enclosure Three-position disconnector as busbar disconnector and feeder earthing switch Make-proof grounding with vacuum circuit breaker Width 600 mm for all versions up to 24 kV Plug-in, single-pole, solid-insulated busbars with outer conductive coating Cable termination with external cone connection system to EN 50181

Operator safety

5

■ Safe-to-touch and hermetically-sealed

primary enclosure ■ All high-voltage parts, including the cable

6

■ ■

7 ■

8

■ ■

sealing ends, busbars and voltage transformers are surrounded by grounded layers or metal enclosures Capacitive voltage indication for checking for ”dead“ state Operating mechanisms and auxiliary switches safely accessible outside the primary enclosure (switchgear enclosure) Type-tested enclosure and interrogation interlocking provide high degree of internal arcing protection Arc-fault-tested acc. to IEC 60 298 No need to interfere with the SF6-insulation

Fig. 29: Gas-insulated swichgear with vacuum circuit-breakers

Operational reliability

9

■ Hermetically-sealed primary enclosure

■

10 ■

■

■

for protection against environmental effects (dirt, moisture, insects and rodents). Degree of protection IP65 Operating mechanism components maintenance-free in indoor environment (DIN VDE 0670 Part 1000) Breaker-operating mechanisms accessible outside the enclosure (primary enclosure) Inductive voltage transformer metalenclosed for plug-in mounting outside the main circuit Toroidal-core current transformers located outside the primary enclosure, i.e. free of dielectric stress

3/24

■ Complete switchgear interlocking with ■ ■ ■ ■

mechanical interrogation interlocks Welded switchgear enclosure, permanently sealed Minimum fire contribution Installation independent of attitude for feeders without HRC fuses Corrosion protection for all climates

General description

The 8DC11 is the result of the economical combination of SF6-insulation and vacuum technology. The insulating gas SF6 is used for internal insulation only; circuit interruption takes place in standard vacuum breaker bottles. The safety for the personnel and the environment is maximized. The 8DC11 is completely maintenance-free. The welded gas-tight enclosure of the primary part assures an endurance of 30 years without any work on the gas system.

Due to the excellent experience with vacuum circuit breaker gas-insulated switchgear, there is a worldwide rapidly increasing demand of this kind of switchgear even in the so-called low-range field.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type 8DC11

1. Modular design and compact dimensions The 8DC switchboards consist of: ■ The maintenance-free SF6-gas-insulated switching module is three-phase encapsulated and contains the vacuum circuitbreaker and 3 position selector switch (ON/OFF/READY TO EARTH) ■ Parts for which single-phase encapsulation is essential are safe to touch, easily accessible and not located in the switching module, e.g. current and potential transformers ■ The busbars are even single-phase encapsulated, i.e. they are insulated by silicone rubber with an outer grounded coating. The pluggable design assures a high degree of flexibility and makes also the installation of busbar CTs and PTs simple.

1

1 Low-voltage compartment

1

2 Busbar voltage transformer 3 Busbar current transformer 2

4 Busbar

2

5 SF6-filled enclosure 3 4

6 Three-position switch 7 Three-position switch

5

3

operating mechanism

8 Circuit-breaker operating mechanism

6

7

9 Circuit-breaker

4

(Vacuum interrupter)

10 Current transformers

8 2. Factory-assembled well-proven tested components

9

Switchgear based on well-proven components. The 8DC switchgear design is based on assembling methods and components which have been used for years in our SF6insulated Ring Main Units (RMUs). For example, the stainless-steel switchgear enclosure is hermetically-sealed by welding without any gaskets. Bushings for the busbar, cable and PT connection are welded in this enclosure, as well as the rupture disc, which is installed for pressure relief in the unlikely event of an internal fault. Siemens has had experience with this technique since 1982; 50,000 RMUs are running trouble-free. Cable plugs with the so-called outer-cone system have been on the market for many years. The gas pressure monitoring system is neither affected by temperature fluctuations nor by pressure fluctuations and shows clearly whether the switchpanel is ”ready for service“ or not. The monitor is magnetically coupled to an internal gas-pressure reference cell; mechanical penetration through the housing is not required. A design safe and reliable and, of course, wellproven in our RMUs. The vacuum circuit-breaker, i.e. the vacuum interrupters and the operating mechanism, is also used in our standard switchboards. The driving force for the primary contacts of the vacuum interrupters is transferred via metal bellows into the SF6gas-filled enclosure. A technology that has been successfully in operation in more than 100,000 vacuum interrupters over 20 years.

10

12 PT disconnector

12

13 Voltage transformers

11 Double cable connection with T-plugs

11

5

14 Cable

6

15 Pressure relief duct 13

7 14 15

8

Fig. 30: Cross section through switchgear type 8DC11

2

5

3

9 1 ”Ready for service“ indicator 2 Pressure cell 1

3 Red indicator: Not ready

10

4 Green indicator: Ready 5 Magnetic coupling Stainless-steel enclosure filled with SF6 gas at 0.5 bar (gauge) at 20 °C

4

Fig. 31: Principle of gas monitoring (with ”Ready for service“ indicator)

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/25

SF6-Insulated Switchgear Type 8DC11

1

2

3

4

5

6

7

8

3. Current and potential transformers as per user’s application

4. No gas work at site and simplified installation

A step forward in switchgear design without any restriction to the existing system! New switchgear developments are sometimes overdesigned with the need for highly sophisticated secondary monitoring and protection equipment, because currentand potential-measuring devices are used with limited rated outputs. The result: Limited application in distribution systems due to interface problems with existing devices; difficult operation and resetting of parameters. The Siemens 8DC switchgear has no restrictions. Current and potential transformers with conventional characteristics are available for all kinds of protection requirements. They are always fitted outside the SF6-gas-filled container in areas of singlepole accessibility, the safe-to-touch design of both makes any kind of setting and testing under all service conditions easy. Current transformers can be installed in the cable connection compartment at the bushings and, if required additionally, at the cables (inside the cable connection compartment). Busbar CTs for measuring and protection can be placed around the silicone-rubber-insulated busbars in any panel. Potential transformers are of the metalclad pluggable design. Busbar PTs are designed for repeated tests with 80% of the rated power-frequency withstand voltage, cable PTs can be isolated from the live parts by means of a disconnection device which is part of the SF6-gas-filled switching module. This allows high-voltage testing of the switchboard with AC and the cable with DC without having to remove the PTs.

The demand for reliable, economical and maintenance-free switchgear is increasing more and more in all power supply systems. Industrial companies and power supply utilities are aware of the high investment and service costs needed to keep a reliable network running. Preventive maintenance must be carried out by trained and costly personnel. A modern switchgear design should not only reduce the investment costs, but also the service costs in the long run! The Siemens 8DC switchgear has been developed to fulfill those requirements. The modular concept with the maintenance-free units does not call for installation specialists and expensive testing and commissioning procedures. The switching module with the circuit-breaker and the three-position disconnector is sealed for life by gas-tight welding without any gaskets. All other high-voltage components are connected by means of plugs, a technology well-known from cable plugs with long- lasting service and proven experience. All cables will be connected by cable plugs with external cone connection system. In the case of XLPE cables, several manufacturers even offer cable plugs with an outer conductive coating (also standard for the busbars). Paper-insulated mass-impregnated cables can be connected as well by Raychem heat-shrinkable sealing ends and adapters. The pluggable busbars and PTs do not require work on the SF6 system at site. Installation costs are considerably reduced (all components are pluggable) because, contrary to standard GIS, even the site

9

HV tests can be omitted. Factory-tested quality is ensured thanks to simplified installation without any final adjustments or difficult assembly work. 5. Minimum space and maintenancefree, cost-saving factors Panel dimensions reduced, cable-connection compartment enlarged! The panel width of 600 mm and the depth of 1225 mm are just half of the truth. More important is the maximized size of the 8DC switchgear cable-connection compartment. The access is from the switchgear front and the gap from the cable terminal to the switchgear floor amounts to 740 mm. There is no need for any aisle behind the switchgear lineup and a cable cellar is superfluous. A cable trench saves civil engineering costs and is fully sufficient with compact dimensions, such as width 500 mm and depth 600 mm. Consequently, the costs for the plot of land and civil work are reduced. Even more, a substation can be located closer to the consumer which can also solve cable routing problems. Busbar Features ■ Single-pole, plug-in version ■ Made of round-bar copper, silicon-

insulated ■ Busbar connection with cross pieces

and end pieces, silicon-insulated ■ Field control with the aid of electro-

■ ■ ■ ■

conductive layers on the silicon-rubber insulation (both inside and outside) External layers earthed with the switchgear enclosure to permit access Insensitive to dirt and condensation Shock-hazard protected in form of metal covering Switchgear can be extended or panels replaced without affecting the SF6 gas enclosures.

10

Fig. 32: Plug-in busbar (front view with removed low-voltage panel)

3/26

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type 8DC11

1

2

3 Fig. 33: Vacuum circuit-breaker (open on operating-mechanism side)

4 4 5

6

7

8

2

9 3

1 Primary part SF6-insulated, with vacuum interrupter 2 Part of switchgear enclosure 3 Operating-mechanism box (open) 4 Fixed contact element 5 Pole support 6 Vacuum interrupter 7 Movable contact element 8 Metal bellows 9 Operating mechanism

1

5

6

Fig. 34: Vacuum circuit-breaker (sectional view)

Circuit-breaker panel

Disconnector panel

7 Switch-disconnector panel with fuses

Busbar section

Metering

8

1)

9

10

Basic versions Vacuum circuit-breaker panel and three-position disconnector

Disconnector panel with three-position disconnector

Switch-disconnector panel with three-position switch disconnector and HV HCR fuses

Optional equipment indicated by means of broken lines can be installed/omitted in part or whole.

Busbar section with 2 three-position disconnectors and vacuum circuit-breaker in one panel

Switch-disconnector panel with three-position switch disconnector and HV HCR fuses

1) Current transformer: electrically, this is assigned to the switchpanel, its actual physical location, however, is on the adjacent panel.

Fig. 35: Switchpanel versions

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/27

SF6-Insulated Switchgear Type 8DC11

1

Weights and dimensions

Technical data

[kV]

Rated voltage

2

3

4

5

7.2

15

17.5

24

Rated power-frequency withstand voltage

[kV]

20

28

36

38

50

Rated lightning impulse withstand voltage

[kV]

60

75

95

95

125

Rated short-circuit breaking current Rated short-time current, 3 s

Width

[mm]

600

Height

[mm]

2250

Depth

single-busbar [mm] double-busbar [mm]

1225 2370

Weight single-busbar [kg] (approx.) double-busbar [kg]

max. [kA]

25

[kA]

63

63

63

63

63

Rated busbar current

[A]

1250

1250

1250

1250

1250

Rated feeder current

max. [A]

1250

1250

1250

1250

1250

25

25

25

25 Cable connection systems

Rated short-circuit making current

Features ■ 8DC11 switchgear for thermoplastic-

■ ■

100

80

63

63

50

■

Fig. 36: Technical data of switchgear type 8DC11 ■

7

8

9

10

■

Climate and ambient conditions

Internal arc test

The 8DC11 fixed-mounted circuit breaker is fully enclosed and entirely unaffected by ambient conditions. ■ All medium-voltage switching devices are enclosed in a stainless-steel housing, which is welded gas-tight and filled with SF6 gas ■ Live parts outside the switchgear enclosure are single-pole enclosed ■ There are no points at which leakage currents of high-voltage potentials are able to flow off to ground ■ All essential components of the operating mechanism are made of noncorroding materials ■ Ambient temperature range: –5 to +55°C.

Tests have been carried out with 8DC11 switchgear in order to verify its behavior under conditions of internal arcing. The resistance to internal arcing complies with the requirements of: ■ IEC 60 298 AA ■ DIN VDE 0670 Part 601, 9.84 These guidelines have been applied in accordance with PEHLA Guideline No. 4.

3/28

700 1200

Fig. 37

Rated current of switchdisconnector panels with fuses max. fuse [A]

6

12

Protection against electric shock and the ingress of water and solid foreign bodies

insulated cables with cross-sections up to 630 mm2 Standard cable termination height of 740 mm High connection point, simplifying assembly and cable-testing work Phase reversal simple, if necessary, due to symmetrical arrangement of cable sealing ends Cover panel of cable termination compartment earthed Nonconnected feeders: – Isolate – Ground – Secure against re-energizing (e.g. with padlock)

Types of cable termination Circuit-breaker and disconnector panels with cable T-plugs for bushings, with M16 terminal thread according to EN 50181 type C. Switch disconnector panels with elbow cable plugs for bushings, with plug-in connection according to EN 50181 type A.

The 8DC11 fixed-mounted circuit breaker offer the following degrees of protection in accordance with IEC 60 259: ■ IP3XD for external enclosure ■ IP65 for high-voltage components of switchpanels without HV HRC fuses

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type 8DC11

1 Low-voltage compartment 5 1

1

2 Operating mechanism 3 Cable connection 4 Current transformer

6 7 8

2

2

5 Panel link 6 Busbar 7 Gas compartment

3

8 Three-position switch 9 Voltage transformer

4 3 4

5 9

6

Fig. 38: Double busbar: Back-to-back arrangement (cross section)

7 Single cable

Double cable

Termination for surge arrester

Termination for switch disconnector panel

8

9

10

Fig. 39: Types of cable termination, outer cone system

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/29

SF6-Insulated Switchgear Type 8DA/8DB10

1

Gas-insulated switchgear type 8DA/8DB10 ■ Single-busbar: type 8DA

2

3

■ ■ ■ ■ ■ ■ ■

Double-busbar: type 8DB From 7.2 to 40.5 kV Single and double-busbar Gas-insulated Type-tested Metal-clad (encapsulated) Compartmented Fixed-mounted vacuum breaker

Specific features ■ Practically maintenance-free compact

4 ■ ■

5

6

■ ■

switchgear for the most severe service conditions Fixed-mounted maintenance-free vacuum breakers Only two moving parts and two dynamic seals in gas enclosure of each pole Feeder grounding via circuit-breaker Only 600 mm bay width and identical dimensions from 7.2 to 40.5 kV

Safety and reliability ■ Safe to touch – hermetically-sealed

grounded metal enclosure. ■ All HV and internal mechanism parts

maintenance-free for 20 years

7

■ Minor gas service only after 10 years ■ Arc-fault-tested ■ Single-phase encapsulation –

no phase-to-phase arcing ■ All switching operations from dead-front

8

freely and safely accessible tions available ■ Positive mechanical interlocking ■ External parts of instrument transform-

ers free of dielectric stresses.

10

The switchgear type 8DA10 represents the successful generation of gas-insulated medium-voltage switchgear with fixed-mounted, maintenance-free vacuum circuit-breakers. The insulating gas SF6 is used for internal insulation only; circuit interruption takes place in standard vacuum breaker bottles. 1. Encapsulation All high-voltage conductors and interrupter elements are enclosed in two identical cast-aluminum housings, which are arranged at 90° angles to each other. The aluminum alloy used is corrosion-free. The upper container carries the copper busbars with its associated vacuum-potted epoxy insulators, and the three-way selector switch for the feeder with the three positions ON/ISOLATED/GROUNDING SELECTED. The other housing contains the vacuum breaker interrupter. The two housings are sealed against each other, and against the cable connecting area by arc-proof and gas-tight epoxy bushings with O-ring seals. Busbar enclosure and breaker enclosures form separate gas compartments. The hermetical sealing of all HV components prevents contamination, moisture, and foreign objects of any kind – the leading cause of arcing faults – from entering the switchgear. This reduces the requirement for maintenance and the probability of a fault due to the above to practically zero. All moving parts and items requiring inspection and occasional lubrication are readily accessible.

operating panel ■ Live line test facility on panel front ■ Drive mechanism and CT secondaries ■ Fully insulated cable and busbar connec-

9

General description

Tolerance to environment ■ Hermetically-sealed enclosure protects

all high-voltage parts from the environment ■ Installation independent of altitude ■ Corrosion protection for all climates.

3/30

2. Insulation medium Sulfur-hexafluoride (SF6) gas is the prime insulation medium in this switchgear. Vacuum-potted cast-resin insulators and bushings supplement the gas and can withstand the operating voltage in the extremely unlikely case of a total gas loss in a compartment. The SF6 gas serves additionally as corrosion inhibiter by keeping oxygen away from the inner components. The guaranteed leakage rate of any gas compartment is less than 1% per year. Thus no scheduled replenishment of gas is required. Each compartment has its own gas supervision by contact-pressure gauges.

3. Three-position switch and circuitbreaker The required isolation of any feeder from the busbar, and its often desired grounding is provided by means of a sturdy, maintenance-free three-way switch arranged between the busbars and the vacuum breaker bottles. This switch is mechanically interlocked with the circuit breaker. The operations ”On/Isolated“ and ”Isolated/ Grounding selected“ are carried out by means of two different rotary levers. The grounding of the feeder is completed by closing the circuit-breaker. To facilitate replacement of a vacuum tube with the busbars live, the switch is located entirely within the busbar compartment. The vacuum circuit-breakers used are of the type 3AH described on pages 3/74 ff of this section. Mounted in the gas-insulated switchgear, the operating mechanism is placed at the switchgear front and the vacuum interrupters are located inside the gas filled enclosures. The number of operating cycles is 30,000. Since any switching arc that occurs is contained within the vacuum tube, contamination of the insulating gas is not possible. 4. Instrument transformers Toroidal-type current transformers with multiple secondary windings are arranged outside the metallic enclosure around the cable terminations. Thus there is no high potential exposed on these CTs and secondary connections are readily accessible. All commonly used burden and accuracy ratings are available. Bus metering and measuring are by inductive, gas-insulated potential transformers which are plugged into fully insulated and gas-tight bushings on top of the switchgear. 5. Feeder connections All commonly used solid-dielectric insulated single and three-phase cables can be connected conveniently to the breaker enclosures from below. Normally, fully insulated plug-in terminations are used. Also, fully insulated and gas-insulated busbar systems of the DURESCA/GAS LINK type can be used. The latter two termination methods maintain the fully insulated and safe-to-touch concept of the entire switchgear, rendering the terminations maintenance-free as well. In special cases, air-insulated conventional cable connection is available.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type 8DA/8DB10

8DA10

1 1

1 2 3 4 5 6

2 3 4

6

7 8

7 8

9 10 11 12 13

9 10 11

Low-voltage cubicle Secondary equipment (SIPROTEC 4) Busbar Cast aluminum Disconnector Operating mechanism and interlocking device for three-position switch Three-position switch CB pole with upper and lower bushings CB operating mechanism Vacuum interrupter Connection Current transformer Rack

12

2

3

4

5

13

6

Fig. 40: Schematic cross-section for switchgear type 8DA10, single-busbar

8DB10

7 1 2 3 4 5

8

9 6 7 8

10

9 10 11 12 13

Fig. 41: Schematic cross-section for switchgear type 8DB10, double-busbar

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/31

SF6-Insulated Switchgear Type 8DA/8DB10

6. Low-voltage cabinet

1

2

3

4

5

6

All feeder-related electronic protection devices, auxiliary relays, and measuring and indicating devices are installed in metal-enclosed low-voltage cabinets on top of each breaker bay. A central terminal strip of the lineup type is also located there for all LV customer wiring. PCB-type protection relays and individual-type protection devices are normally used, depending on the number of protective functions required.

2250

7. Interlocking system The circuit-breaker is fully interlocked with the isolator/grounding switch by means of solid mechanical linkages. It is impossible to operate the isolator with the breaker closed, or to remove the switch from the GROUND SELECTED position with the breaker closed. Actual grounding is done via the circuit-breaker itself. Busbar grounding is possible with the available make-proof grounding switch. If a bus sectionalizer or bus coupler is installed, busbar grounding can be done via the three-way switch and the corresponding circuit-breaker of these panels. The actual isolator position is positively displayed by rigid mechanical indicators.

600 1525

Fig. 42: Dimensions of switchgear type 8DA10, double-busbar

Switchgear type 8DB10, double-busbar

8

9

The double-busbar switchgear has been developed from the components of the switchgear type 8DA10. Two three-position switches are used for the selection of the busbars. They have their own gas-filled components. The second busbar system is located phasewise behind the first busbar system. The bay width of the switchgear remains unchanged; depth and height of each bay are increased (see dimension drawings Fig. 43). For parallel bus couplings, only one bay is required.

850**

7

2350

10

2660

Fig. 43: Dimensions of switchgear type 8DB10, double-busbar

3/32

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type 8DA/8DB10

Degrees of protection In accordance with IEC 60529: ■ Degree of protection IP 3XD: The operating mechanism and the lowvoltage cubicle have degree of protection IP 3XD against contact with live parts with objects larger than 1 mm in diameter. Protection against dripping water is optionally available. Space heaters inside the operating mechanism and the LV cabinet are available for tropical climates. ■ Degree of protection IP 65: By the nature of the enclosure, all highvoltage-carrying parts are totally protected against contact with live parts, dust and water jets.

Cable cross-sections for plug-in terminations 1) Interface type

1

Rated voltage 7.2/12/15 kV

17.5/24 kV

36 kV

Cable cross-section [mm2]

[mm2]

[mm2]

2

up to 300

up to 300

up to 185

3

400 to 630

400 to 630

240 to 500

4

up to 1200

up to 1200

up to 1200

2

3 1) The plug-in terminations are of the inside cone type acc. to EN 50181: 1997

Fig. 44

4

Installation The switchgear bays are shipped in prefabricated assemblies up to 5 bays wide on solid wooden pallets, suitable for rolling, skidding and fork-lift handling. Double-busbar sections are shipped as single or double bays. The switchgear is designed for indoor operation; outdoor prefabricated enclosures are available. Each bay is set onto embedded steel profile sections in a flat concrete floor, with suitable cutouts for the cables or busbars. All conventional cables can be connected, either with fully insulated plug-in terminations (preferred), or with conventional air-insulated stress cones. Fully insulated busbars are also connected directly, without any HV-carrying parts exposed. Operating aisles are required in front of and (in case of double-busbar systems) behind the switchgear lineup.

Weights and dimensions

Width

[mm]

600

single-busbar (8DA) double-busbar (8DB)

[mm] [mm]

2250 2350

Depth

single-busbar (8DA) double-busbar (8DB)

[mm] [mm]

1525 2660

Weight per bay

single-busbar (8DA) double-busbar (8DB)

[kg] [kg]

Height

5

6

7

approx. 600 approx. 1150

Fig. 45

8 Ambient temperature and current-carrying capacity: Rated ambient temperature (peak)

40 °C

Rated 24-h mean temperature

35 °C

Minimum temperature

–5 °C

At elevated ambient temperatures, the equipment must be derated as follows (expressed in percent of current at rated ambient conditions).

30 °C

=

110%

35 °C

=

105%

40 °C

=

100%

45 °C

=

90%

50 °C

=

80%

9

10

Fig. 46

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/33

SF6-Insulated Switchgear Type 8DA/8DB10

1

Options for circuit-breaker feeder of switchgear type 8DA10, single-busbar

Busbar accessories

2

Mounted on breaker housing

Mounted on current transformer housing Panel connection options per phase

3 Voltage transformer, nondisconnectable or disconnectable

4 or

5

Totally gas or solid-insulated bar

Mounted on panel connections

or

or

Sectionalizer without additional space required

or

3 x plug-in cable termination Interface type 3

Mounted on panel connections

or

Busbar current transformer

or

5 x plug-in cable termination Interface type 2

Mounted on panel connections

2 x plug-in cable termination Interface type 2 and 3 with plug-in voltage transformer

Mounted on panel connections

6

8

or

Mounted on panel connections

Cable or bar connection, nondisconnectable or disconnectable

or

7

Make-proof earthing switch

1 x plug-in cable termination Interface type 2 and 3

Mounted on panel connections

3 x plug-in cable termination Interface type 2

or

Current transformer

or

9

Totally solid-insulated bar with plug-in voltage transformer or

10

Air-insulated cable termination or

Surge arrester

Air-insulated bar

Plug-in cable terminations are of the Inside Cone Type acc. to EN 50181: 1997 Fig. 47

3/34

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type 8DA/8DB10

Options for circuit-breaker feeder of switchgear type 8DB10, double-busbar

1 BB1 BB2

Busbar accessories

2 Mounted on breaker housing

Mounted on current transformer housing Panel connection options per phase BB1

BB1

BB2

or

BB2

Voltage transformer, nondisconnectable

Voltage transformer, disconnectable

BB1

BB1

BB1

BB2

BB2

or

or and

BB2

BB1 BB2

or BB1 and BB2

or

BB2

or

BB1

Make-proof earthing switch

or

or

Mounted on panel connections

5

Mounted on panel connections

3 x plug-in cable termination Interface type 2

Cable or bar connection, nondisconnectable

or

Cable or bar connection, disconnectable

or

Busbar current transformer

or

Sectionalizer BB2 without additional space required

Mounted on panel connections

4 1 x plug-in cable termination Interface type 2 and 3

Totally gas or solid-insulated bar BB1

3

6

3 x plug-in cable termination Interface type 3

7

5 x plug-in cable termination Interface type 2

Current transformer

2 x plug-in cable termination Interface type 2 and 3 with plug-in voltage transformer

Mounted on panel connections

8

9

or Totally solid insulated bar with plug-in voltage transformer or Air-insulated cable termination or

10

Surge arrester

Air-insulated bar

Plug-in cable terminations are of the Inside Cone Type acc. to EN 50181: 1997 Fig. 48

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/35

SF6-Insulated Switchgear Type 8DA/8DB10

1

2

3

4

5

Technical data Rated voltage

[kV]

7.2

12

15

17.5

24

36

40.5

Rated power-frequency withstand voltage

[kV]

20

28

36

38

50

70

85

Rated lightning-impulse withstand voltage

[kV]

60

75

95

95

125

170

180 (200)

Rated short-circuit breaking current and rated short-time current 3s,

max.

[kA]

40

40

40

40

40

40

40

Rated short-circuit making current

max.

[kA]

110

110

110

110

110

110

110

Rated current busbar with twin busbar

max. max.

[A] [A]

3150 4500

3150 4500

3150 4500

3150 4500

3150 4500

2500 4500

2500 4500

Rated current feeder

max.

[A]

2500

2500

2500

2500

2500

2500

2500

Fig. 49

6

Further Applications Power Supply for Railway Systems

7

8

9

10

Type 8DA10 SF6 gas-insulated switchgear (single and double-pole) (Fig. 50a). This type has been upgraded for service in railway networks with a basic-impulse insulation level (BIL) of 200 (230) kV. It is therefore the ideal switchgear for 1 x 25 kV and 2 x 25 kV (50/60 Hz) railway networks. Typical occurrences in railway networks prove the suitability of the switchgear for such applications: ■ Effects of lightning strikes ■ Switching impulse voltage ■ Breaking under asynchronous conditions with a 180° phase difference ■ Recovery voltage after breaking under asynchronous conditions with a 180° phase difference.

3/36

Twin-Busbar System (TBS) This primary distribution switchgear is based on the worldwide proven SF6-insulated type 8DA / 8DB switchgear and has been supplemented by a twin busbar (Fig. 50b). The use of standard components allowed us in a remarkably short time to create from a modular, compact type of switchgear a high-current system unbeatable in terms of minimal space requirement. The modular-structure busbars were arranged in twin-busbar form. This twin-busbar system is supplied via a twin circuit-breaker and respective twin disconnector. All standard panel types required (incoming feeder, coupler, outgoing feeder) are available.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type 8DA/8DB10

Further applications for 8DA/8DB

1

a) Power Supply for Railway Systems 1-pole

2-pole

2

3

4

5

6 b) High Power Busbar 4500 A with Twin Busbar System (TBS) 8DA (single busbar)

8DB (double busbar)

7

8

9

10

Fig. 50 a/b

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/37

SF6-Insulated Switchgear Type NX PLUS

1

Gas-insulated switchgear type NX PLUS

Specific features

Panel construction

■ Used in transformer stations and sub-

stations ■ Practically maintenance-free compact

2

3

From 7.2 up to 36 kV Single-busbar Metal enclosed/metal-clad Three-pole primary enclosure Gas-insulated Fixed-mounted circuit-breakers Three-position switch as busbar disconnector and feeder earthing switch ■ Make-proof earthing with vacuum circuit-breaker ■ ■ ■ ■ ■ ■ ■

switchgear for the most severe service conditions ■ Panel width 600 mm (with bus sectionalizer panel 900 mm) for all voltages up to 36 kV

Panel with integrated inside cone Features ■ Rated voltage up to 36 kV ■ Rated short-circuit breaking current

up to 31.5 kA

General description The switchgear type NX PLUS combines compact design, long service life, climateresistance and freedom from maintenance

■ Rated normal currents of busbars and

feeders up to 2500 A.

1. Reliablility ■ Hermetically sealed primary enclosure

4

■

■

5

■

6

■ ■ ■

7 ■

for protection against environmental effects (dirt, moisture and small animals) Operating mechanism components maintenance-free in indoor environment (DIN VDE 0670 Part 1000) Breaker operating mechanisms accessible outside the switchgear container (primary enclosure) Inductive voltage transformers metalenclosed for plug-in mounting outside the main circuit Ring-core current transformers located outside the primary enclosure Complete interrogative interlocking system Welded switchgear container, sealed for life Minimum fire load.

2. Insulation medium Due to the excellent experience with vacuum circuit-breaker gas-insulated switchgear, there is a worldwide rapidly increasing demand of this kind of switchgear even in the so-called low-range field. The insulating gas SF6 is used for internal insulation only; circuit interruption takes place in standard vacuum breaker bottles. The safety for the personnel and the environment is maximized. The NX PLUS is completely maintenancefree. The welded gas-tight enclosure of the primary part assures a full service life without any work on the gas system.

8

9

10 Fig. 51: SF6-insulated switchgear Type NX PLUS with SIPROTEC

Panel with separate inside cone Features ■ Rated voltage up to 36 kV ■ Rated short-circuit breaking current

up to 31.5 kA ■ Rated normal currents of busbars and

feeders up to 2500 A.

Panel with outside cone Features ■ Rated voltage up to 24 kV ■ Rated short-circuit breaking current up

to 25 kA ■ Rated normal currents of busbars up

to 2500 A and feeders up to 1250 A.

Fig. 52

3/38

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type NX PLUS

1 1 Door of low-voltage compartment 2 SIPROTEC 4 bay controller, type 7SJ63, for control and protection

3 EMERGENCY OFF pushbutton 4 Door to mechanical control board 6 7 29 8 1

9

15

10 18

4 5

3

SF6-insulated

8 Three-pole busbar system 9 Three-position switch, SF6-insulated, with the three positions: ON – OFF – EARTH

4

10 Module coupling between busbar

11 3

5 Cover of connection compartment 6 Busbar cover 7 Busbar module, welded,

16 17

2

2

module and circuit-breaker module

12

19

29

20

13

21

12 Vacuum interrupter of circuit-breaker 13 Pressure-relief duct

14

22

14 Integrated cable connection as inside

11 Circuit-breaker module, welded, SF6-insulated, with integrated cable connection

cone

5

6

15 Optional low-voltage compartment 1100 mm high

16 Standard low-voltage compartment 730 mm high

17 Ring-core current transformer 18 Manual and motor operating

29 23 17 24 29 25

7

mechanism of three-position switch

19 Mechanical control board 20 Manual and motor operating

8

mechanism of circuit-breaker

21

21 Voltage transformer connection

22

22 Cable connection compartment 23 Module coupling between

socket as inside cone

circuit-breaker and cable connection module

9

24 Cable connection module, welded, SF6-insulated, with separate cable connection

29 11

25 Separate cable connection as inside cone

17

26 Voltage transformer connection

26 27 28

socket as outside cone

22

27 Cable connection as outside cone 28 Connection cables 29 Rupture diaphragm

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/39

10

SF6-Insulated Switchgear Type NX PLUS

Tolerance to environment

1

2

■ Hermetically-sealed enclosure protects

all high-voltage parts from the environment ■ Installation independent of altitude ■ Corrosion protection for all climates.

up to [kV]

24

Rated frequency

[Hz]

50/60

50/60

Rated short-time power-frequency voltage

[kV]

50

70 (85*)

Operator safety

Rated lightning impulse voltage

[kV]

125

170 (185*)

■ Safe-to-touch and hermetically sealed

Rated short-circuit breaking current and rated short-time withstand current, 3 s

max. [kA]

31.5

31.5

Rated short-circuit making current

max. [kA]

80

80

Rated normal current of busbar

max.

[A]

2500

2500

Rated normal current of feeder

max.

[A]

2500

2500

■

3 ■

4

■

■ ■

5

Technical data

primary enclosure All HV parts, including the cable sealing ends, busbars and voltage transformers, are surrounded by earthed layers or metal enclosures Capacitive voltage detection system for verification of safe isolation from supply Operating mechanisms and auxiliary switches safely accessible outside the primary enclosure (switchgear container) Protective system interlock to prevent operation when enclosure is open Type-tested enclosure and interrogative interlocks provide high degree of internal arcing protection.

Rated voltage

*) On request Fig. 53

Weights and dimensions Width Width of sectionalizer panel (≤ 2000 A)

6

7

36 (40.5*)

[mm]

600 900

Width sectionalizer panel (> 2000 A)

[mm]

1200

Height Height with higher LV compartment

[mm] [mm]

2450 2630

Depth

[mm]

1600

[kg]

800

Weight per panel (approx.) Fig. 54

8

9

10

3/40

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type NX PLUS

Control board

Solid-state HMI with panel door closed

SIPROTEC 4 bay controller, type 7SJ63

1

(The basic unit for this is in the low-voltage compartment)

Bay controller Solid-state HMI (human-machine interface) SIPROTEC 4 bay controller, type 7SJ63, PROFIBUS-capable, control and protection for stand-alone or master operation.

2 5

1 2

3 3

6

4

4 1 LCD for process and equipment information, graphically as feeder mimic control diagram and as text Keys for navigating in menus, in feeder mimic control diagram and for entering values Keys for controlling the process Four programmable function keys for frequently performed actions Fourteen programmable LEDs with possible application-related inscriptions for indicating any desired process and equipment data 6 Two key-operated switches for “changeover between local and remote control“ and “changeover between interlocked and non-interlocked position“.

2 3 4 5

5

6

Fig. 55

Mechanical control board Features

Mechanical control board with panel door open

1 ON/OFF position indication for threeposition switch

■ Arranged behind panel door ■ Opening of door switches of the

2 ON/OFF operating shaft for three-position

1 2 3 4

SIPROTEC 4 bay controller, type 7SJ63, automatically ■ Three-position switch interlocked with circuit-breaker ■ Cancelling of feeder earthing can be blocked mechanically.

5 6 7 8 9 10 11 12 13 14 15

switch 3 OFF/EARTHING PREPARED operating shaft for three-position switch 4 OFF/EARTHING PREPARED position indication for three-position switch 5 Mimic diagram 6 Ready indication for busbar module (gas compartment monitoring) 7 Ready indication for circuit-breaker module (gas compartment monitoring) 8 Interlocking for preselection 9 ON/OFF position indication for circuitbreaker 10 Manual spring charging for circuit-breaker 11 ON pushbutton for circuit-breaker with sealable cap 12 OFF pushbutton for circuit-breaker 13 Locking device for ”feeder earthed” 14 ”Spring charged” indication for circuitbreaker 15 Operating cycle counter for circuit-breaker

Fig. 56

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/41

7

8

9

10

SF6-Insulated Switchgear Type NX PLUS

Options for circuit-breaker panel

1

2

with cable connection as inside cone for: ■ Rated voltage up to 36 kV ■ Rated short-circuit breaking current up to 31.5 kA ■ Rated normal currents of busbars and feeders up to 2500 A.

Busbar fittings

Fittings before circuit-breaker module Fittings after circuit-breaker module 4) 1)

Also available as Disconnector panel.

Panel connection fittings

1)

3 Panel connection versions

4

Capacitive voltage detection system

1 x plug-in cable, sizes 2 or 3

Voltage transformer, plug-in type

Current transformer

5 or 2)

1 x plug-in cable, size 2

or

2 x plug-in cable, sizes 2 or 3

or 2)

Voltage transformer, plug-in type

or

3 x plug-in cable, sizes 2 or 3

or 2)

Surge arrester, plug-in type

or

4 x plug-in cable, size 2

and 3)

Busbar current transformer

or

Solidinsulated bar (e.g. Duresca bar)

6

7

8

9

10

Surge arrester, plug-in type

1) Capacitive voltage detection system according to LRM or IVDS system. 2) Not possible with rated normal current of feeder of 2500 A. 3) Not possible with busbar voltage transformer. 4) Requires cable connection with container for separate inside cone.

Fig. 57

3/42

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type NX PLUS

Options for circuit-breaker panel with cable connection as outside cone for: ■ Rated voltage up to 24 kV ■ Rated short-circuit breaking current up to 25 kA ■ Rated normal currents of busbars up to 2500 A and feeders up to 1250 A.

1

Busbar fittings

Fittings before circuit-breaker module Fittings after circuit-breaker module

Also available as Disconnector panel.

1) 1)

2

Panel connection fittings

3 Panel connection versions Capacitive voltage detection system

1 x plug-in cable

Voltage transformer, disconnectable

Current transformer

4

5 or

1 x plug-in cable, size 2

or

2 x plug-in cable

6 or

or

and 2)

Voltage transformer, plug-in type

or

3 x plug-in cable

7

Surge arrester, plug-in type

8

Busbar current transformer

9

10

Surge arrester or limiter, plug-in type

1) Capacitive voltage detection system according to LRM or IVDS system. 2) Not possible with busbar voltage transformer.

Fig. 58

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/43

SF6-Insulated Switchgear Type NX PLUS

Options for sectionalizer panel

1

■ Rated voltage up to 36 kV ■ Rated short-circuit breaking current up to

Sectionalizer panel

31.5 kA ■ Rated normal currents of busbar up to

2500 A.

Busbar fittings

2

Fittings before circuitbreaker module

1)

3

4

1)

5

and

Capacitive voltage detection system

Current transformer

Busbar current transformer

6 1) Not possible with rated normal current of busbar of 2500 A.

Fig. 59

7

8

9

10

3/44

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

SF6-Insulated Switchgear Type NX PLUS

Standards, specifications, guidelines

Internal arc test, resistance to internal arcs Internal arc test

Standards The NX PLUS switchgear complies with the standards and specifications listed below: ■ VDE 0670, Part 1000 ■ VDE 0670, Part 6 ■ VDE 0670, Part 101 et seq. ■ VDE 0670, Part 2 ■ IEC 60 694 ■ IEC 60 298 ■ IEC 60 056 ■ IEC 60 129. In accordance with the obligatory harmonization in the European Community, the national standards of the member countries conform to IEC 60 298. Type of service location NX PLUS switchgear can be used as an indoor installation in accordance with VDE 0101: ■ Outside closed electrical operating areas in locations not accessible to the general public. Tools are required to remove switchgear enclosures. ■ In closed electrical operating areas. A closed electrical operating area is a room or area which is used solely for the operation of electrical installations. This type of area is locked at all times and accessible only to authorized trained personnel and other skilled staff. Untrained or unskilled persons must be accompanied by authorized personnel. Definition “Make-proof earthing switches“ are earthing switches with short-circuit making capacity (VDE 0670, Part 2).

Tests have been carried out with NX PLUS switchgear, in order to verify its behaviour under conditions of internal arcing. The resistance to internal arcing complies with the requirements of ■ VDE 0670, Part 6, Appendix AA ■ IEC 60 298, Appendix AA. Resistance to internal arcs The possibility of faults in the NX PLUS fixed-mounted circuit-breaker switchgear is much less than in previous types, due to the single-pole enclosure of external components and the SF6 insulation of the switchgear: ■ All external fault-causing factors have been eliminated, such as: – Pollution deposits – Moisture – Small animals and foreign bodies ■ Maloperations are prevented by the clear, logical layout of the operating elements ■ The three-position switch and the vacuum circuit-breaker provide short-circuitproof earthing of the feeder. Should arcing occur in spite of this, the pressure is relieved towards the rear into a duct. In the improbable event of a fault inside the switchgear container, the SF6 insulation restricts the arc energy to only about 1/3 of that for air. The pressure-relief facility in the rear panel of the switchgear container is designed to operate in an overpressure range of 2 to 3.5 bar. The gases are discharged towards the rear into a duct. The pressure-relief duct diverts the gases upwards.

Protection against electric shock, the ingress of water and solid foreign bodies The NX PLUS fixed-mounted circuit-breaker switchgear is fully enclosed and entirely unaffected by climatic influences. ■ All medium-voltage switching devices are enclosed in a stainless steel container, which is welded gas-tight and filled with SF6 gas. ■ Live parts outside the switchgear container are single-pole insulated and screened. ■ There are no points at which leakage currents of high-voltage potential are able to flow off to earth. ■ All essential components of the operating mechanism are made of non-corroding materials.

1

2

3

4

Degrees of protection The NX PLUS fixed-mounted circuit-breaker switchgear offers the following degrees of protection in accordance with IEC 60 529: ■ IP3XD for external enclosure ■ IP65 for parts under high voltage

5

6

7

8

9

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/45

Secondary Distribution Switchgear and Transformer Substations

General 1

2

3

4

5

6

7

8

9

10

Features

Standards ■ The fixed-mounted ring-main units

Maximum personnel safety The secondary distribution network with its basic design of ring-main systems with counter stations as well as radial-feed transformer substations is designed in order to reduce network losses and to provide an economical solution for switchgear and transformer substations. These are installed with an extremely high number of units in the distribution network. Therefore, high standardization of equipment is necessary and economical. The described switchgear will show such qualities. To reduce the network losses the transformer substations should be installed directly at the load centers. The transformer substations consisting of medium-voltage switchgear, transformers and low-voltage distribution can be designed as prefabricated units or single components installed in any building or rooms existing on site. Due to the large number of units in the networks the most economical solution for such substations should have climate-independent and maintenance-free equipment so that operation of the equipment does not need any maintenance work during its lifetime. For such transformer substations, nonextensible and extensible switchgear, for instance ring-main units (RMUs), have been developed using SF6 gas as insulation and arc-quenching medium in the case of loadbreak systems (RMUs), and SF6 gas insulation and vacuum as arc-quenching medium in the case of extensible modular switchgear, consisting of load-break panels with or without fuses, circuit-breaker panels and metering panels. Siemens has developed RMUs in accordance with these requirements. Ring-main units type 8DJ10, 8DJ20, 8DJ40 and 8DH10 are type-tested, factory-finished, metal-enclosed, SF6-insulated indoor switchgear installations. They verifiably meet all the demands encountered in network operation by virtue of the following features:

3/46

■ High-grade steel housing and cable con-

■ ■ ■ ■ ■

nection compartment tested for resistance to internal arcing Logical interlocking Guided operating procedures Capacitive voltage indication integrated in unit Safe testing for dead state on the closed-off operating front Locked, grounded covers for fuse assembly and cable connection compartments

type 8DJ10, 8DJ20, 8DJ40 and 8DH10 comply with the following standards:

IEC Standard

VDE Standard

IEC 60 694

VDE 0670 Part 1000

IEC 60 298

VDE 0670 Part 6

IEC 60 129

VDE 0670 Part 2

IEC 60 282

VDE 0670 Part 4

IEC 60 265-1

VDE 0670 Part 301

Safe, reliable, maintenance-free

IEC 60 420

VDE 0670 Part 303

■ Corrosion-resistant hermetically welded

IEC 60 056

VDE 0670 Part 101–107

IEC 61 243-5

EVDE 0682 Part 415 EN 61 243-5(E)

■

■ ■

■

■

high-grade steel housing without seals and resistant to pressure cycles Insulating gas retaining its insulating and quenching properties throughout the service life Single-phase encapsulation outside the housing Clear indication of readiness for operation, unaffected by temperature or altitude Complete protection of the switch disconnector/fuse combination, even in the event of thermal overload of the HV HRC fuse (thermal protection function) Reliable, maintenance-free switching devices

Fig. 60

In accordance with the harmonization agreement reached by the European Union member states that their national specifications conform to IEC Publication No. 60 298. Resistance to internal arcing – IEC Publ. 60 298, Annex AA – VDE 0670, Part 6

Excellent resistance to ambient conditions

For further information please contact:

■ Robust, corrosion-resistant and mainte-

Fax: ++ 49 - 91 31-73 46 36

nance-free operating mechanisms ■ Maintenance-free, all-climate, safe-totouch cable terminations ■ Creepage-proof and free from partial discharges ■ Maintenance-free, safe-to-touch, all-climate HV HRC fuse assembly Environmental compatibility ■ Simple, problem-free disposal of the

SF6 gas ■ Housing material can be recycled by

normal methods

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Switchgear and Transformer Substations

1 Primary distribution G

2

3

4 Secondary distribution

5

6

7

8

9

RMU for transformer substations Type 8DJ

Extensible switchgear for consumer substations Type 8DH or 8AA

Extensible switchgear for substations with circuit-breakers Type 8DH or 8AA

10

Fig. 61: Secondary Distribution Network

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/47

Secondary Distribution Selection Matrix

1

2

Switchgear

Codes, standards

Type of installation

Insulation

Enclosure

Switching device

Appl

3

RMU subst conve conne Stand

4 Nonextensible

5

6

SF6-gas-insulated

Metal-enclosed fixed-mounted

Load-break switch

Medium-voltage indoor switchgear, type-tested according to: IEC 60 298 DIN VDE 0670, Part 6

RMU subst cable Stand

RMU low s housi

SF6-gas-insulated

Metal-enclosed fixed-mounted

Load-break switch Vacuum CB Measurement panels

Cons CB sw up to

Air-insulated

Metal-enclosed

Load-break switch Vacuum CB Measurement panels

Cons CB sw up to

7 Extensible

8

9 Transformer substations

Execution of the transformer substation

10 Prefabricated, factory-assembled substations, with different type of housings, made of concrete, galvanized sheet steel or aluminium

Fig. 62

3/48

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Selection Matrix

1 Application

Switchgear type

Technical data Rated lightning impulse withstand voltage at: 7.2/12 17.5/24 [kV] [kV]

RMU for transformer substations, plug and conventional cable connection, Standard Range 1

8DJ10

RMU for transformer substations, high cable connection, Standard Range 2

8DJ20

60/75

Page Rated voltage [kV]

95/125

7.2–24

Maximum rated short-time withstand current [kA] [kA] 1s 3s

25

20

2 Rated normal current Busbar max. [A]

Feeder [A]

3 630

up to 630

3/50

4 60/75

7.2–12

25

14.3

7.2–24

20

20

630

95/125

up to 630

3/53

5 RMU for extremely low substation housings

8DJ40

60/75

95/125

7.2–24

20

11.5

630

up to 630

3/58

6 Consumer substation/ CB switchgear up to 630 A

Consumer substation/ CB switchgear up to 630 A

8DH10

8AA20

7.2–15

25

20

17.5–24

20

11.5

7.2–12

20

11.5

1000

up to 1000

17.5–24

16

9.3

630

up to 630

Type of housing

HV section Medium-voltage switchgear type

Transformer rating

8FB10

8DJ10

630 kVA

8FB11

8DJ20

8FB12

8DJ40

60/75

60/75

95/125

1250

up to 630

3/60

7

95/125

3/64

8

9 Package substation type (Example)

8FB1

8FB15

Page

10 3/66

up to 1000/1250 kVA

8FB16 8FB17

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/49

Secondary Distribution Switchgear Type 8DJ10

1

2

3

4

Ring-main unit type 8DJ10, 7.2–24 kV nonextensible, SF6-insulated Standard Range 1 Typical use SF6-insulated, metal-enclosed fixed-mounted ring-main units (RMU) type 8DJ10 are used for outdoor transformer substations and indoor substation rooms with a variability of 25 different schemes as a standard delivery program. More than 60,000 RMUs of type 8DJ10 are in worldwide operation. Specific features ■ Maintenance-free, all-climate ■ SF6 housings have no seals ■ Remote-controlled motor operating

5 ■

■

6

■ ■

7

■

■

8

mechanism for all auxiliary voltages from 24 V DC to 230 V AC Easily extensible by virtue of trouble-free replacement of units with identical cable connection geometry Standardized unit variants for operatorcompatible concepts Variable transformer cable connection facilities Excellent economy by virtue of ambient condition-resistant, maintenance-free components Versatile cable connection facilities, optional connection of mass-impregnated or plastic-insulated cables or plug connectors Cables easily tested without having to be dismantled

Fig. 63: Example: Scheme 10

9

10

3/50

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Switchgear Type 8DJ10

Technical data (rated values)1)

1

Rated voltage

[kV]

7.2

12

15

17.5

24

Rated frequency

[Hz]

50/60

50/60

50/60

50/60

50/60

Rated current of cable feeders

[A]

400/630

400/630

400/630

400/630

400/630

Rated current of transformer feeders2)

[A]

200

200

200

200

200

Rated power-frequency withstand voltage

[kV]

20

28

36

38

50

Rated lightning-impulse withstand voltage

[kV]

60

75

95

95

125

Rated short-circuit making current of cable feeder switches

[kA]

63

52

52

52

40

Rated short-circuit making current of transformer switches

[kA]

25

25

25

25

25

Rated short-circuit current, 1s

[kA]

25

21

21

21

16

Ambient temperature

[°C]

min. – 50 max. +80

min. – 50 max. +80

min. – 50 max. +80

min. – 50 max. +80

min. – 50 max. +80

2

3

4

5

6

1) Higher values on request 2) Depending on HV HRC fuse assembly

7

Fig. 64

8 1 2 3

1

HRC fuse boxes

2

Hermetically-scaled welded stainless steel enclosure

3

SF6 insulation/quenching gas

4

Three-position load-break switch

5

Feeder cable with insulated connection alternative with T-plug system

6

Maintenance-free stored energy mechanism

4 6

9

10

5

Fig. 65: Cross section of SF6-insulated ring-main unit 8DJ10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Fig. 66: “Three-position load-break switch” ON–OFF–EARTH

3/51

Secondary Distribution Switchgear Type 8DJ10

1

Examples out of 25 standard schemes With integrated HV HRC fuse assembly

2

3 Scheme 10

Scheme 71

Scheme 81

4 Dimensions [mm]

5

6

Width Depth Height Version with low support frame Version with high support frame

800

1170

1630

800

800

800

1360

1360

1360

1760

1760

1760

Scheme 61

Scheme 64

Without HV HRC fuses

Combinations

7

8

Scheme 70

9

10

Dimensions [mm] Width Depth Height Version with low support frame Version with high support frame

1450

1700

2070

800

800

800

1105

1360

1360

1505

1760

1760

Fig. 67: Schemes and dimensions

3/52

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Switchgear Type 8DJ20

Ring-main unit type 8DJ20, 7.2–24 kV non extensible, SF6-insulated Standard Range 2

1

2

Typical use Same system as type 8DJ10 (page 3/50) but other geometrical dimensions and design, also single panel for transformer feeder. ■ Substations with control aisles ■ Compact substations, substations by pavements ■ Tower base substations ■ 7.2 kV to 24 kV ■ Up to 25 kA

3

4

Specific features ■ Minimal dimensions ■ Ease of operation ■ Proven components from the ■ ■ ■ ■

■ ■ ■ ■

8DJ10 range Metal-enclosed All-climate Maintenance-free Capacitive voltage taps for – incoming feeder cable – outgoing transformer feeder Optional double cable connection Optional surge arrester connection Transformer cable connected via straight or elbow plug Motor operating mechanism for auxiliary voltages of 24 V DC – 230 V AC

5

6 Fig. 68: Example: Scheme 10 (width 1060 mm)

7

8

8DJ20 switchgear ■ Overall heights 1200 mm, 1400 mm ■ ■ ■ ■

or 1650 mm High cable termination For cable T-plugs Detachable lever mechanism Option: rotary operating mechanism

9

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/53

Secondary Distribution Switchgear Type 8DJ20

Technical data

1

2

Rated voltage Ur

[kV]

7.2

12

15

17.5

24

Rated insulation level: Rated power-frequency withstand voltage Ud

[kV]

20

28

36

38

50

[kV]

60

75

95

95

125

[Hz]

50/60

50/60

50/60

50/60

50/60

[A]

400 630

400 630

400 630

400 630

400 630

[A]

200

200

200

200

200

Rated short-time withstand current Ik, 1 s

[kA]

20 25

20 25

21 25

21 25

16 21

Rated short-time withstand current Ik, 3 s

[kA]

20

20

20

20

20

Rated peak-withstand current Ip

[kA]

50 63

50 63

52 63

52 63

40 52

Rated short-time making current Ima for transformer feeder

[kA]

25

25

25

25

25

[kA]

50 63

50 63

52 63

52 63

40 52

[°C]

–40 to +70

[hpa]

500

500

500

500

500

Rated lightning impulse voltage Up Rated frequency fr

3

Rated normal current Ir for ring-main feeders for transformer feeders depending on the HV HRC fuse

4

5

for ring-main feeder

6

Ambient temperature T Rated filling pressure (at 20 °C) for insulation pre and for operation prm

7

Fig. 69

8

9

10

3/54

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Switchgear Type 8DJ20

1

Transformer feeder Section A-A

A

1 HV HRC fuse compartment

1

2 RMU vessel, filled with SF6 gas

2

3 Three position load-break switch ON-OFF-Earth

2

4 Transformer cable with elbow

3

5 Spring-assisted/stored-energy

plugs

3

mechanism

5

4 4

5

6 A

Standard Cable termination for elbow plugs (Option:cable-T-plugs), cable bushing directed downlwards

7

Fig. 70: Panel design / Example: ring-main transformer block, scheme 10

8

9

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/55

Secondary Distribution Switchgear Type 8DJ20

Transformer feeder panels with HV HRC fuses

1

Ring-main units without HV HRC fuses

Combinations with HV HRC fuses2)

2

3

4 Scheme 01

Scheme 21

Scheme 11/32/70/84

Scheme 20

Scheme 10

5

6

7

Ring-main feeders

9

0

2–5

1

2

1

1

0

1

1

Cable connection with cable plugs, compatible with bushings ASG 36-400 to DIN 47 636 with thread connection M 16 x 2, connection at front Transformer feeders

8

0

Cable connection with cable plugs, compatible with bushings ASG 24-250 to DIN 47 636, optionally ASG 36 400 with plug/thread connection M 16 x 2 Location of bushings optionally at front or at bottom

10

–

Dimensions in mm Width

510

710

710 + 350/per additional feeder

710

1060

Depth

780

780

780

780

780

Height

1200

1200

1200

1200

1200

1400

1400

1400

1400

1400

1760

1760

1760

1760

1760

Fig. 71

3/56

2)

others on request

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

e 10

Secondary Distribution Switchgear Type 8DJ20

1

2

3

4 Scheme 71

Scheme 72

Scheme 81

Scheme 82

5

3

4

2

6

3

7 1

1

2

2

8

9

10 1410

1760

1410

1760

780

780

780

780

1200

1200

1200

1200

1400

1400

1400

1400

1760

1760

1760

1760

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/57

Secondary Distribution Switchgear Type 8DJ40

1

Ring-main unit type 8DJ40, 7.2–24 kV nonextensible, SF6-insulated Typical use

2

3

SF6-insulated, metal-enclosed, fixedmounted. Ring-main units type 8DJ40 are mainly used for transformer compact substations. The main advantage of this switchgear is the extremely high cable termination for easy cable connection and cable testing work. Specific features

4

5

6

7

8

8DJ40 units are type-tested, factoryfinished, metal-enclosed SF6-insulated switchgear installations and meet the following operational specifications: ■ High level of personnel safety and reliability ■ High availability ■ High-level cable connection ■ Minimum space requirement ■ Uncomplicated design ■ Separate operating mechanism actuation for switch disconnector and make-proof grounding switch, same switching direction in line with VDEW recommendation ■ Ease of installation ■ Motor operating mechanism retrofittable ■ Optional stored-energy release for ring cable feeders ■ Maintenance-free ■ All-climate

9

10

Fig. 72: Nonextensible RMU, type 8DJ40

Technical data (rated values)1) Rated voltage

[kV]

12

24

Rated frequency

[Hz]

50

50

Rated current of cable feeders

[A] 400/630*

400/630*

Rated current of transformer feeders

[A]

≤ 200

≤ 200

Rated power-frequency withstand voltage

[kV]

28

50

Rated lightning-impulse withstand voltage

[kV]

75

125

Rated short-circuit making current of cable feeder switches

[kA] 50 (31.5)*

40 (31.5)*

Rated short-circuit making current of transformer switches2)

[kA]

25

25

Rated short-time current of cable feeder switches

[kA] 20 (12.5)*

16 (12.5)*

Rated short-circuit time

[s]

1

1

Rated filling pressure at 20 °C

[barg]

0.5

0.5

Ambient temperature

[°C]

min. – 40 max. + 70

min. – 40 max. + 70

1) Higher values on request 2) Depending on HV HRC fuse assembly * With snap-action/stored-energy operating mechanism up to 400 A/12.5 kA, 1s

Fig. 73

3/58

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Switchgear Type 8DJ40

1

2

3 Scheme 10

Scheme 32

Scheme 71

4

5 Dimensions [mm] Width

1140

909

1442

Depth

760

760

760

Height

1400/1250

1400/1250

1400/1250

6

Fig. 74: Schemes and dimensions

7

8

9

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/59

Secondary Distribution Switchgear Type 8DH10

1

Consumer substation modular switchgear type 8DH10 extensible, SF6-insulated Typical use

2

3

4

SF6-insulated, metal-enclosed fixed-mounted switchgear units type 8DH10 are indoor installations and are mainly used for power distribution in customer substations or main substations. The units are particularly well suited for installation in industrial environments, damp river valleys, exposed dusty or sandy areas and in built-up urban areas. They can also be installed at high altitude or where the ambient temperature is very high. Specific features

5

6

7

8

9

10

8DH10 fixed-mounted switchgear units are type-tested, factory-assembled, SF6-insulated, metal-enclosed switchgear units comprising circuit-breaker panels, disconnector panels and metering panels. They meet the demands made on medium-voltage switchgear, such as ■ High degree of operator safety, reliability and availability ■ No local SF6 work ■ Simple to install and extend ■ Operation not affected by environmental factors ■ Minimum space requirements ■ Freedom from maintenance is met substantially better by these units than by earlier designs. ■ Busbars from panel blocks are located within the SF6 gas compartment. Connections with individual panels and other blocks are provided by solid-insulated plug-in busbars ■ Single-phase cast-resin enclosed insulated fuse mounting outside the switchgear housing ensures security against phase-to-phase faults ■ All live components are protected against humidity, contamination, corrosive gases and vapours, dust and small animals ■ All normal types of T-plugs for thermoplastic-insulated cables up to 300 m2 cross-section can be accommodated

Fig. 75: Extensible, modular switchgear type 8DH10

■ The units have a grounded outer enclo-

■ ■

■

■

■ ■

3/60

sure and are thus shockproof. This also applies to the fuse assembly and the cable terminations. Plug-in cable sealing ends are housed in a shock-proof metalenclosed support frame Fuses and cable connections are only accessible when earthed All bushings for electrical and mechanical connections are welded gas-tight without gaskets Three-position switches are fitted for load switching, disconnection and grounding, with the following switch positions: closed, open and grounded. Make-proof earthing is effected by the three-position switch (shown on page 3/51) Each switchgear unit can be composed as required from single panels and (preferably) panel blocks, which may comprise up to three combined single panels The 8DH10 switchgear is maintenancefree Integrated current transformer suitable for digital protection relays and protection systems for CT operation release

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Switchgear Type 8DH10

1 1 1

2

2 3 4

2

5

3

3

6 7

4

8

5

4

9 10

1 2 3 4 5

Fuse assembly Three-position switch Transformer/cable feeder connection Hermetically-welded gas tank Plug-in busbar up to 1250 A

1 2 3 4 5

6 Three-position switch 7 Ring-main cable termination

Low-voltage compartment Circuit-breaker operating mechanism Metal bellow welded to the gas tank Pole-end kinematics Spring-assisted mechanism

(400/630 A T-plug system) 8 Hermetically-welded RMU housing 9 Busbar (up to 1250 A) 10 Overpressure release system

5

6 Fig. 76: Cross section of transformer feeder panel

Fig. 77: Cross section of circuit-breaker feeder panel

7

LV cabinet 1 2

8 3 4

9 extensible

extensible

1 Plug bushing welded to the gas tank

10

2 Silicon adapter 3 Silicon-insulated busbar 4 Removable insulation cover to assemble the system at site

Fig. 78: Combination of single panels with plug-in type, silicon-insulated busbar. No local SF6 gas work required during assembly or extension

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Fig. 79: Cross-section of silicon-plugged busbar section.

3/61

Secondary Distribution Switchgear Type 8DH10

1

2

3

4

5

Technical data (rated values)1) Rated voltage

[kV]

7.2

12

15

17.5

24

Rated frequency

[Hz]

50/60

50/60

50/60

50/60

50/60

Rated power-frequency withstand voltage

[kV]

20

28

36

38

50

Rated lightning-impulse withstand voltage

[kV]

60

75

95

95

125

Rated short-circuit breaking current of circuit-breakers

[kA]

25

25

20

20

16

Rated short-circuit current, 1s

[kA]

25

25

20

20

16

Rated short-circuit making current

[kA]

63

63

50

50

50

[A]

630 1250

630 1250

630 1250

630 1250

630 1250

– Circuit-breaker panels [max. A] [max. A] – Ring-main panels [max. A] – Transformer panels2)

400/630 400/630 200

400/630 400/630 200

400/630 400/630 200

400/630 400/630 200

400/630 400/630 200

Rated current of bus sectionalizer panels – without HV HRC fuses – with HV HRC fuses2)

400/630 200

400/630 200

400/630 200

400/630 200

400/630 200

Busbar rated current Feeder rated current

6

7

[A] [A]

1) Higher values on request 2) Depending on HV HRC fuse assembly

8

Fig. 80

9

10

3/62

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Switchgear Type 8DH10

Individual panels

1

2

3 Ring-main panel

Transformer panel

Circuit-breaker panel

Billing metering panel

Busbar metering and grounding panel

4

5

Dimensions [mm] Width

500

500

350

600*/850

500

Depth

780

780

780

780

780

Height

1400

2000

1400

1400/2000**

1450

6

* Width for version with combined instrument transformer ** With low-voltage compartment

7

Blocks

8

9 2

Ring-main feeders

3 Ring-main feeders

2

Transformer feeders

3

Transformer feeders

10 Dimensions [mm] Width

700

1050

1000

1500

Depth

780

780

780

780

Height

1400

1400

1400

1400

Fig. 81: Schemes and dimensions

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/63

Secondary Distribution Switchgear Type 8AA20

1

2

3

4

Consumer substation modular switchgear type 8AA20, 7.2–24 kV extensible, air-insulated Typical use This air-insulated modular indoor switchgear is used as a flexible system with a lot of panel variations. Panels with fused and unfused load-break switches, with trucktype vacuum circuit-breakers and metering panels can be combined with air-insulated busbars. The 8AA20 ring-main units are type-tested, factory-assembled metal-enclosed indoor switchgear installations. They meet operational requirements by virtue of the following features: Personnel safety

5

Fig. 82: Extensible modulares switchgear type 8AA20

■ Sheet-steel enclosure tested for resist-

ance to internal arcing ■ All switching operations with door

Technical data (rated values)1)

closed

6

7

■ Testing for dead state with door closed ■ Insertion of barrier with door closed

Rated voltage and insulation level

Safety, reliability/maintenance

Rated power-frequency withstand voltage

■ Complete mechanical interlocking ■ Preventive interlocking between barrier

Rated lightning-impulse withstand voltage

and switch disconnector ■ Door locking

8

Excellent resistance to ambient conditions ■ High level of pollution protection by

virtue of sealed enclosure in all operating states ■ Insulators with high pollution-layer resistance

9

7.2

12

17.5

24

[kV]

20

28

38

50

[kV]

60

75

95

125

Rated short-time current 1s [kA]

20

20

16

16

Rated short-circuit making current

[kA]

50

50

40

40

Rated busbar current1)

[A]

630

630

630

630

Rated feeder current

[A]

630

630

630

630

1) Higher values on request

Fig. 83

Dimensions

Width

Height

Depth

12/24 kV [mm]

[mm]

12/24 kV [mm]

Load-breaker panels

600/750

2000

665/790 or 931/1131

Circuit-breaker panels

750/750

2000

931/1131

Metering panels

600/750

2000

665/790 or 931/1131

10

Fig. 84: Dimensions

3/64

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Switchgear Type 8AA20

Standards ■ The switchgear complies with the

1

following standards:

IEC Standard

VDE Standard

IEC 60 694

VDE 0670 Part 1000

IEC 60 298

VDE 0670 Part 6

IEC 60 129

VDE 0670 Part 2

IEC 60 282

VDE 0670 Part 4

IEC 60 265-1

VDE 0670 Part 301

IEC 60 420

VDE 0670 Part 303

IEC 60 056

VDE 0670 Part 101–107

IEC 61 243-5

EVDE 0682 Part 415 EN 61 243-5(E)

1 1

2

2 2

3

3

4 1 Load-break switch 2 Grounding switch

1 2 3 4

Fig. 86a: Cross-section of cable feeder panel

Fig. 86b: Cross-section of withdrawable type vacuum circuit-breaker panel

Vacuum circuit-breaker Current transformer Potential transformer Grounding switch

4

Fig. 85

In accordance with the harmonization agreement reached by the EC member states, their national specifications conform to IEC Publ. No. 60 298.

5

Resistance to internal arcing – IEC Publ. 60298, Annex AA – VDE 0670, Part 6

6

Type of service location

Individual panels

Air-insulated ring-main units can be used in service locations and in closed electrical service locations in accordance with VDE 0101.

Circuit-breaker panels Scheme 11/12

7 Scheme 13/14

Specific features

8

■ Switch disconnector fixed-mounted ■ Switch disconnector with integrated

central operating mechanism ■ Standard program includes numerous ■

■ ■ ■ ■ ■

circuit variants Operations enabled by protective interlocks; the insulating barrier is included in the interlocking Extensible by virtue of panel design Cubicles compartmentalized (option) Minimal cubicle dimensions without extensive use of plastics Lines up with earlier type 8AA10 Withdrawable circuit-breaker section can be moved into the service and disconnected position with the door closed

Load-break panels Scheme 21/22

Scheme 23/24

9

Scheme 25/26

10 Metering and cable panels Scheme 33/34

Fig. 87: Schemes

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/65

Secondary Distribution Transformer Substations

1

2

3

4

5

Factory-assembled packaged substations type 8FB1 (example) Factory-assembled transformer substations are available in different designs and dimensions. As an example of a typical substation program, type 8FB1 is shown here. Other types are available on request. The transformer substations type 8FB1 with up to 1000 kVA transformer ratings and 7.2–24 kV are prefabricated and factory-assembled, ready for connection of network cables on site. Special foundation not necessary. ■ Distribution substations for public power supply ■ Nonwalk-in type ■ Switchgear operated with open substation doors General features/Applications ■ Power supply for LV systems, especially

in load centers for public supply

Fig. 88: Steel-clad outdoor substation 8FB1 for rated voltages up to 24 kV and transformers up to 1000 kVA

■ Power supply for small and medium

6

7

8

9

10

industrial plants with existing HV side cable terminations ■ Particularly suitable for installation at sites subject to high atmospheric humidity, hostile environment, and stringent demands regarding blending of the station with the surroundings ■ Extra reliability ensured by SF6-insulated ring-main units type 8DJ, which require no maintenance and are not affected by the climate Brief description The substation housing consists of a torsion-resistant bottom unit, with a concrete trough for the transformer, embedded in the ground, and a hot-dip galvanized steel structure mounted on it. It is subdivided into three sections: HV section, transformer section and LV section. The lateral section of the concrete trough serves as mounting surface for the HV and LV cubicles and also closes off the cable entry compartments at the sides. These compartments are closed off at the bottom and front by hot-dip galvanized bolted steel covers. Four threaded bushes for lifting the complete substation are located in the floor of the concrete trough. The substations are arc-fault-tested in order to ensure safety for personnel during operation and for the pedestrians passing by the installed substation.

3/66

HV section (as an example):

LV section:

8DJ SF6-insulated ring-main unit (for details please refer to RMUs pages 2/48–2/61)

The LV section can take various forms to suit the differing base configurations. The connection to the transformer is made by parallel cables instead of bare conductors. Incoming circuit: Circuit breaker, fused load disconnector, fuses or isolating links. Outgoing circuits: Tandem-type fuses, load-break switches, MCCB, or any other requested systems. Basic measuring and metering equipment to suit the individual requirements.

Technical data: ■ Rated voltages and insulation levels

■ ■ ■ ■

7.2 kV 12 kV 15 kV 17.5 kV 24 kV 60 75 95 95 125 kV (BIL) Rating of cable circuits: 400 / 630 A Rating of transformer circuits: 200 A Degree of protection for HV parts: IP 65 Ambient temperature range: –30°C/+55°C (other on request)

Transformer section: Oil-cooled transformer with ratings up to max. 1000 kVA. The transformer is connected with the 8DJ10 ring-main unit by three single-core screened 35 mm2 plastic insulated cables. The connection is made by means of right-angle plugs or standard air-insulated sealing ends possible at the transformer side.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Secondary Distribution Transformer Substations

Substation housing type:

8FB10

8FB11

8FB12

8FB15

8FB16

8FB17

1

HV section: SF6 -insulated ring-main unit (RMU)

2

H High-voltage

H

T

L

section

H

H

T

T L

T

L

H

T L

T

T Transformer section

L

H

L

H

3

L Low-voltage section

Transformer rating

630 kVA

630 kVA

630 kVA

1000 kVA

1000 kVA

1000 kVA

4

Overall dimensions, weights: Length Width Height above ground Height overall Floor area Volume Weight without transformer

[mm] [mm] [mm] [mm] [mm2] [mm3] [kg]

3290 1300 1650

2570 2100 1650

2100 2100 1650

3860 1550 1700

3120 2300 1700

2350 2300 1700

2100 4.28 7.06 approx. 2280

2100 5.40 8.91 approx. 2530

2100 4.41 7.28 approx. 2400

2350 5.98 10.17 approx. 3400

2350 7.18 12.20 approx. 3800

2350 5.41 9.19 approx. 3600

5

6

Fig. 89: Technical data, dimensions and weights

7

8

9 Fig. 90: HV section: Compact substation 8FB with SF6-insulated RMU (two loop switches, one transformer feeder switch with HRC fuses)

Fig. 91: Transformer section: Cable terminations to the transformer, as a example

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Fig. 92: LV section: Example of LV distribution board

10

3/67

Industrial Load Center Substation

Introduction 1

2

3

Industrial power supply systems call for a maximum level of operator safety, operational reliability, economic efficiency and flexibility. And they likewise necessitate an integral concept which includes “before” and “after” customer service, which can cope with the specific load requirements and, above all, which is tailored to each individually occurring situation. With SITRABLOC® such a concept can be easily turned into reality.

For further information please contact:

4

Fax: ++ 49 - 91 31-73 15 73

General 5

6

Fig. 93

SITRABLOC is an acronym for SIemens TRAnsformer BLOC-type. SITRABLOC is supplied with power from a medium-voltage substation via a fuse/ switch-disconnector combination and a radial cable. In the load center, where SITRABLOC is installed, several SITRABLOCs are connected together by means of cables or bars.

Substation

8DC11/8DH10

7

Load-centre substation

Features ■ Due to the fuse/switch-disconnector

8

9

10

combination, the short-circuit current is limited, which means that the radial cable can be dimensioned according to the size of the transformer. ■ In the event of cable faults, only one SITRABLOC fails. ■ The short-circuit strength is increased due to connection of several stations in the load center. The effect of this is that, in the event of a fault, large loads are selectively disconnected in a very short time. ■ The transmission losses are optimized since only short connections to the loads are necessary. ■ SITRABLOC has, in principle, two transformer outputs: – 1250 kVA during AN operation (ambient temperature up to 40 °C) – 1750 kVA during AF operation (140% with forced cooling). These features ensure that, if one station fails for whatever reason, supply of the loads is maintained without interruption.

3/68

Supply company's substation

LV busways

Fig. 94: Example of a schematic diagram

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Industrial Load Center Substation

The SITRABLOC components are: ■ Transformer housing with roof-mounted ventilation for AN/AF operating mode ■ GEAFOL Transformer (cast-resin insulated) with make-proof earthing switch AN operating mode: 100% load up to an ambient temperature of 40 °C AF operating mode: 140% load ■ LV circuit-breaker as per transformer AF load ■ Automatic power factor correction equipment (tuned/detuned) ■ Control and metering panel as well as central monitoring interface ■ Universal connection to the LV distribution busway system

LV Busway

1

Tap-Off Unit with HRC Fuses

2 Consumer Distribution incl. Control

3 SITRABLOC

Fig. 95: Location sketch

4 Whether in the automobile or food industry, in paintshops or bottling lines, putting SITRABLOC to work in the right place considerably reduces transmission losses. The energy is transformed in the production area itself, as close as possible to the loads. For installation of the system itself, no special building or fire-protection measures are necessary. Available with any level of output SITRABLOC can be supplied with any level of power output, the latter being controlled and protected by a fuse/switch-disconnector combination. A high-current busbar system into which up to four transformers can feed power ensures that even large loads can be brought onto load without any loss of energy. Due to the interconnection of units, it is also ensured that large loads are switched off selectively in the event of a fault. Integrated automatic power factor correction With SITRABLOC, power factor correction is integrated from the very beginning. Unavoidable energy losses – e.g. due to magnetization in the case of motors and transformers – are balanced out with power capacitors directly in the low-voltage network. The advantages are that the level of active power transmitted increases and energy costs are reduced (Fig. 97).

Technical data Rated voltage Transformer rating AN/AF Transformer operating mode

12 kV and 24 kV

5

1250 kVA/1750 kVA 100% AN up to 40 °C 140% AF

Power factor correction

up to 500 kVAr without reactors up to 300 kVAr with reactors

Busway system Degree of protection

1250 A, 1600 A, 2500 A

Dimensions (min) (LxHxD) Weight approx.

3600 mm x 2560 mm x 1400 mm

6

IP 23 for transformer housing IP 43 for LV cubicles

7

6000 kg

Fig. 96

Reliability of supply

8

With the correctly designed transformer output, the n-1criterion is no longer a problem. Even if one module fails (e.g. a medium-voltage switching device, a cable or transformer) power continues to be supplied without the slightest interruption. None of the drives comes to a standstill and the whole manufacturing plant continues to run reliably. These examples show that, with SITRABLOC, the power is there when you need it – and safe, reliable and economical into the bargain.

9

10

Fig. 97: Capacitor Banks

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/69

Industrial Load Center Substation

N -1 criteria

N-1 operating mode

With the respective design of a factory grid on the MV side as well as on the LV side the so called n-1 criteria is fulfilled. In case one component fails on the line side of the transformer e.g. circuit breaker or transformer or cable to transformer, no interuption of the supply on the LV side will occur.

1 How to understand this mode: Normal operating mode: 4x1250 kVA N -1 operating mode: 3x1750 kVA

AN operating mode (100%) AF operating mode (≤ 140%)

2 Power distribution

Example Fig 98: Load required 5000 kVA = 4 x 1250 kVA. In case one load centre (SITRABLOC) is disconnected from the MV network the missing load will be supplied via the remaining three (N-1) load centres.

3 Supply company’s substation

4 Circuit-breakers and switch disconnectors with HV HRC fuses

Substation

5

t < 10 ms

SITRABLOC SITRABLOC SITRABLOC SITRABLOC

6

M

M

M Production M

M

M

Operator safety Reduced costs Low system losses

7

Fig. 98: N-1 operating mode

8

SITRABLOC is a combination of everything which present-day technology has to offer. Just one example of this are our GEAFOL® cast-resin transformers. Their output: 100% load without fans plus reserves of up to 140% with fans. And as far as persons are concerned, their safety is ensured even in the direct vicinity of the installation. Another example is the SENTRON highcurrent busbar system. It can be laid out in any arrangement, is quick to install and conducts the current wherever you like – with almost no losses. The most important thing, however, is the uniformity of SITRABLOC throughout, irrespective of the layout of the modules.

9

10

Fig. 99: Transformer and earthing switch, LV Bloc

3/70

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Industrial Load Center Substation

The technology at a glance

Information distribution

SITRABLOC can cope with any requirements. Its features include ■ A transformer cubicle with or without fans (AN/AF operation) ■ GEAFOL cast-resin transformers with make-proof earthing switch – AN operation 1250 kVA, AF operation 1750 kVA ■ External medium-voltage switchgear with fuse switch-disconnectors ■ Low-voltage circuit-breakers ■ Automatic reactive-power compensation – up to 500 kVAr unrestricted, up to 300 kVAr restricted ■ The SENTRON high-current busbar system – Connection to high-current busbar systems from all directions ■ An ET 200 /PROFIBUS interface for central monitoring system (if required).

1

2 S7-400

S7-300

S5-155U PROFIBUS-DP

3

4 COROS OP

PG/PC

5 PROFIBUS ET 200B

ET 200C

Field devices

6 Communications interface

7

SITRABLOC ET 200M

12/24 kV P

P

8

GEAFOL transformer with built-on make-proof earthing switch

9 LV installation with circuitbreakers and automatic reactivepower compensation

10 0.4 kV LV busbar system with sliding link (e.g. SENTRON busways)

Option

Fig. 100

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/71

Medium-Voltage Devices Product Range

1

2

3

Devices for medium-voltage switchgear With the equipment program for switchgear Siemens can deliver nearly every device which is required in the mediumvoltage range between 7.2 and 36 kV. Fig. 101 gives an overview of the available devices and their main characteristics. All components and devices conform to international and national standards, as there are:

Device

Rated voltage

Shortcircuit current

Short-time current (3s)

[kV]

[kA]

[kA]

3AH

7.2 … 36

13.1 … 80

13.1 … 80

NX ACT

12

25

25

Outdoor vacuum circuit-breaker

3AF

36

25

25

Components for 3AH VCB

3AY2

12 … 36

16 … 40

16 … 40

Indoor vacuum switch

3CG

7.2 … 24

–

16 … 20

Indoor vacuum contactor

3TL

7.2 … 24

–

8 (1s)

Vacuum interrupter

VS

7.2 … 40.5

12.5 … 80

12.5 … 80

Indoor switch disconnector

3CJ

12 … 24

–

18 … 26 (1s)

Indoor disconnecting and grounding switch

3D

12 … 36

–

16 ... 63 (1s)

HV HRC fuses

3GD

7.2 … 36

31.5 … 80

–

Fuse bases

3GH

7.2 … 36

44 peak withstand current

–

Indoor post insulators, Bushings

3FA 3FH/3FM

3.6 … 36

–

–

Indoor and outdoor current and voltage transformers

4M

12 … 36

–

–

Surge arresters

3E

3.6 … 42

–

–

Indoor vacuum circuit-breaker

Type

Vacuum circuit-breakers

4

■ IEC 60 056 ■ IEC 60 694 ■ BS5311

Vacuum switches ■ IEC 60 265-1

5

in combination with Siemens fuses: ■ IEC 60 420 Vacuum contactors

6

■ IEC 60 470 ■ UL 347

Switch disconnectors

7

■ IEC 60 129 ■ IEC 60 265-1

HV HRC fuses ■ IEC 60 282

8

Current and voltage transformers ■ IEC 60 185, 60 186 ■ BS 3938, 3941 ■ ANSI C57.13

9 For further information please contact: Fax: ++ 49 - 91 31 - 73 46 54

10

Fig. 101: Equipment program for medium-voltage switchgear

3/72

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Product Range

Operating cycles

Rated current mechanical

with rated current

Applications/remarks

Page

All applications, e.g. overhead lines, cables, transformers, motors, generators, capacitors, filter circuits, arc furnaces

3/74

1

with shortcircuit current

[A] 800 … 12,000

10,000 … 120,000

10,000 … 30,000

25 … 100

1250 … 2500

10,000

10,000

25 … 50

1600

10,000

10,000

50

All applications, e.g. overhead lines, cables, transformers, motors, generators, capacitors, filter circuits

3/80

1250 … 2500

–

–

–

Original equipment manufacturer (OEM) and retrofit

3/81

2

3/78

3

4 800

10,000

10,000

–

All applications, e.g. overhead lines, cables, transformers, motors, capacitors; high number of operations; fuses necessary for short-circuit protection

3/82

400 … 800

1x106 ... 3x106

0.25x105 ... 2x106

–

All applications, especially motors with very high number of operating cycles

3/84

630 … 4000

10,000 … 30,000

10,000 … 30,000

25 … 100

For circuit breakers, switches and gas-insulated switchgear

3/85

630

1000

20

–

Small number of operations, e.g. distribution transformers

3/86

5

6

7 630 … 3000

–

–

–

Protection of personnel working on equipment

3/87

6.3 … 250

–

–

–

Short-circuit protection; short-circuit current limitation

3/88

400

–

–

–

Accommodation of HV HRC fuse links

3/88

–

–

–

–

Insulation of live parts from another, carrying and supporting function

3/89

9

10

–

–

–

–

Measuring and protection

3/90

–

–

–

–

Overvoltage protection

3/90

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

8

3/73

Medium-Voltage Devices Type 3AH

1

2

3

4

Indoor vacuum circuit-breakers type 3AH The 3AH vacuum circuit-breakers are three-phase medium-voltage circuit-breakers for indoor installations. The 3AH circuit-breakers are suitable for: ■ Rapid load transfer, synchronization ■ Automatic reclosing up to 31.5 kA ■ Breaking short-circuit currents with very high initial rates of rise of the recovery voltage ■ Switching motors and generators ■ Switching transformers and reactors ■ Switching overhead lines and cables ■ Switching capacitors ■ Switching arc furnaces ■ Switching filter circuits

5

As standard circuit-breakers they are available for the entire medium-voltage range. Circuit-breakers with reduced pole center distances, circuit-breakers for very high numbers of switching cycles and singlephase versions are part of the program. The following breaker types are available: ■ 3AH1 – the maintenance-free circuitbreaker which covers the range between 7.2 kV and 24 kV. It has a lifetime of 10,000 operating cycles ■ 3AH2 – the circuit-breaker for 60,000 operating cycles in the range between 7.2 kV and 24 kV ■ 3AH3 – the maintenance-free circuitbreaker for high breaking capacities in the range between 7.2 kV and 36 kV. It has a lifetime of 10,000 operating cycles ■ 3AH4 – the circuit-breaker for up to 120,000 operating cycles ■ 3AH5 – the economical circuit-breaker in the lower range for 10,000 maintenancefree operating cycles

Properties of 3AH circuit breakers: No relubrication Nonwearing material pairs at the bearing points and nonaging greases make relubrication superfluous on 3AH circuit-breakers up to 10,000 operating cycles, even after long periods of standstill. High availability Continuous tests have proven that the 3AHs are maintenance-free up to 10,000 operating cycles: accelerated temperature/ humidity change cycles between –25 and +60 °C prove that the 3AH functions reliably without maintenance. Assured quality Exemplary quality control with some hundred switching cycles per circuit-breaker, certified to DIN/ISO 9001. No readjustment Narrow tolerances in the production of the 3AH permanently prevent impermissible play: even after frequent switching the 3AH circuit-breaker does not need to be readjusted up to 10,000 operating cycles.

6 Electrical data and products summary

7

8

at Rated short-circuit breaking current1) (Rated short-circuit making current)

[kV]

[kA]

[kA]

[kA]

[kA]

[kA]

[kA]

[kA]

[kA]

[kA]

13.1 (32.8)

16 (40)

20 (50)

25 (63)

31.5 (80)

40 (100)

50 (125)

63 (160)

up to 80 (225)

7.2 12

9

10

Vacuum circuit-breaker (Type)

Rated voltage

3AH1 3AH5

3AH5

3AH5 3AH1

15

3AH1

17.5

3AH1

24

3AH1 3AH5

36

3AH5 800 A

800 A 800 A to to 1250 A 1250 A Rated normal current 1) DC component 36% (higher values on request).

3AH5

3AH5 3AH1

3AH1

3AH1 3AH2

3AH1 3AH2

3AH3

3AH3

3AH1

3AH1 3AH2

3AH1 3AH2

3AH3

3AH3

3AH1

3AH1 3AH2

3AH1 3AH2

3AH3

3AH3

3AH1

3AH1 3AH2

3AH1 3AH2

3AH3

3AH3

3AH38*)

1250 A to 3150 A

1250 A to 3150 A

1250 A to 4000 A

8000 A to 12000 A

3AH1 3AH2

3AH3 3AH4 3AH3 3AH4

800 A to 2500 A

800 A to 1250 A

800 A 1250 A to to 2500 A 2500 A2)

2) 3150 A for rated voltage 17.5 kV.

3AH3 3AH4 2500 A

*) 3 switches in parallel

Fig. 102: The complete 3AH program

3/74

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Type 3AH

3AH1 24 kV, 25 kA, 1250 A

3AH2 24 kV, 25 kA, 2500 A

3AH4 24 kV, 40 kA, 2500 A

1

2

3

4 Fig. 103: Vacuum circuit-breakers type 3AH

5

Advantages of the vacuum switching principle The most important advantages of the principle of arc extinction in a vacuum have made the circuit-breakers a technically superior product and the principle on which they work the most economical extinction method available: ■ Constant dielectric: In a vacuum there are no decomposition products and because the vacuum interrupter is hermetically sealed there are no environmental influences on it. ■ Constant contact resistance: The absence of oxidization in a vacuum keeps the metal contact surface clean. For this reason, contact resistance can be guaranteed to remain low over the whole life of the equipment. ■ High total current: Because there is little erosion of contacts, the rated normal current can be interrupted up to 30,000 times, the short-circuit breaking current an average of 50 times ■ Low chopping current: The chopping current in the Siemens vacuum interrupter is only 4 to 5 A due to the use of a special contact material. ■ High reliability: The vacuum interrupters need no sealings as conventional circuit-breakers. This and the small number of moving parts inside makes them extremely reliable.

6

7

8

Fig. 104: Front view of vacuum circuit-breaker 3AH1

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

9

10

3/75

Medium-Voltage Devices Type 3AH

1

3AH1, 12 kV 20 kA, up to 1250 A 25 kA, up to 1250 A

604 522

520

210

190

210 105

2

473

437

3

60

4

5

Dimensions in mm

3AH1, 3AH2, 12 kV

604 549 210

550 190

210

25 kA, 2500 A, 31.5 kA, 2500 A, 40 kA, 3150 A

105

6 437

587

7 109 Dimensions in mm

565

8 3AH1, 24 kV

9

16 kA, up to 1250 A, 20 kA, up to 1250 A, 25 kA, up to 1250 A

708 662 275

565 190 275 105

10

535 437

60 Dimensions in mm Fig. 105a: Dimensions of typical vacuum circuit-breakers type 3AH (Examples)

3/76

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Type 3AH

708 670

3AH1, 3AH2, 24 kV 20kA, 2500 A 25 kA, 2500 A

595

1

190 275

275

105

2 648

437

3 109 Dimensions in mm

3AH3, 12 kV

610

750 275

211

4 483

275

5

63 kA, 4000 A

6 733

564

7 776

Dimensions in mm

8 3AH3, 3AH4, 36 kV

820 350

211

526

350

31.5 kA, 2500 A, 40 kA, 2500 A

9

734 1000

564

Dimensions in mm

853

10

612

Fig. 105b: Dimensions of typical vacuum circuit-breakers type 3AH (Examples)

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/77

Medium-Voltage Devices Type NXACT

1

Indoor vacuum circuit-breaker module type NXACT General

2

NXACT combines the advantages of vacuum circuit-breakers with additional integrated functions. More functions

3

Disconnector, earthing switch, operator panel and interlock are integrated in a single breaker module. The module is supplied pretested and ready for installation. Ease of integration …

4

5

6

For the system builder, this means minimum project planning, ease of installation even with subsequent retrofitting, no more testing, simplified logistics – these features mean that NXACT is unbeatable, even with the overall cost of the substation. Its compact design minimizes installation and commissioning time. In operation, NXACT is notable for the clear layout of its control panel, which is always accessible at the front of the switchgear. Applications

7

common medium-voltage switchgear breakers for all switching duties in indoor installations ■ For switching all resistive, inductive and capacitive currents. Typical uses

9

10

Technical data

■ Universal circuit-breaker module for all ■ As three-pole medium-voltage circuit-

8

Fig. 106: NXACT vacuum circuit-breaker module, 12 kV

■ ■ ■ ■ ■ ■ ■

Overhead transmission lines Cables Transformers Capacitors Filter circuits* Motors Reactor coils

Rated voltage

[kV]

12

Rated power-frequency withstand voltage

[kV]

28

Rated lightning impulse withstand voltage

[kV]

75

Rated frequency

[Hz]

50/60

Rated short-circuit breaking current (max.)

[kA]

25

Rated short-circuit making current (max.)

[kA]

63

Rated short-time withstand current 3 sec. (max.)

[kA]

25

Rated normal current

[A]

1250/2500

Fig. 107

* Filter circuits cause an increase in voltage at the series-connected switching device.

3/78

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Type NXACT

Features ■ Integrated, mechanical interlocks be-

1

tween operating mechanisms. ■ Integrated, mechanical switch position

■ ■ ■ ■

■

indications for circuit-breaker, withdrawable part and earthing switch function (optional). Easy to withdraw, since only withdrawable part is moved. Fixed interlocking of circuit-breaker module with a switchpanel is possible. Manual or motor operating mechanism (optional for the operating mechanisms). Enforced connection of low-voltage plug with the switchpanel, as soon as the module is installed in a panel. Maintenance-free operating mechanisms within scope of switching cycles.

2

3

4

5

6

Fig. 108

NXACT vacuum circuit-breaker module

7 Front view

Side view 188

200

517

8 275 730

140*

375

767

9

100

10 586 646

156

584 Operating mechanism for earthing switch

Dimensions in mm

* Travel

Fig. 109

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/79

Medium-Voltage Devices Type 3AF

1

2

3

4

5

Outdoor vacuum circuitbreakers type 3AF The Siemens outdoor vacuum circuitbreakers are structure-mounted, easy-toinstall vacuum circuit-breakers for use in systems up to 36 kV. The pole construction is a porcelain-clad construction similar to conventional outdoor high-voltage switchgear. The triple-pole circuit-breaker is fitted with reliable and well proven vacuum interrupters. Adequate phase spacing and height have been provided to meet standards and safety requirements. It is suitable for direct connection to overhead lines. The type design incorporates a minimum of moving parts and a simplicity of assembly assuring a long mechanical and electrical life. All the fundamental advantages of using vacuum interrupters like low operating energy, lightweight construction, virtually shock-free performance leading to ease of erection and reduction in foundation requirements, etc. have been retained. The Siemens outdoor vacuum circuitbreakers are designed and tested to meet the requirements of IEC 60 056/IS 13118.

Technical data Vacuum circuit-breaker type Rated voltage

[kV]

36

Rated frequency

[Hz]

50/60

Rated lightningimpulse withstand voltage

[kV]

170

Rated power-frequency withstand voltage (dry and wet)

[kV]

70

Rated short-circuit breaking current

[kA]

25

Rated short-circuit making current

[kA]

63

Rated current

[A]

Side view

Advantages at a glance

7

■ ■ ■ ■ ■

High reliability Negligible maintenance Suitable for rapid autoreclosing duty Long electrical and mechanical life Completely environmentally compatible

1600

Fig. 111: Ratings for outdoor vacuum circuit-breakers

Front view

6

Type 3AF

1830 190

285

725

725

350

350

285

8

3045

9

2410 1810

10

450 650

1730 1930 Dimensions in mm Fig. 110: Outdoor vacuum circuit-breaker type 3AF for 36 kV

3/80

Fig. 112: Dimensions of outdoor circuit-breaker type 3AF for 36 kV

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Components, Type 3AY2

Components for vacuum circuitbreaker type 3AH

1

Vacuum circuit-breakers are available in fixed-mounted as well as withdrawable form. When they are installed in substations, isolating contacts, as well as fixed mating contacts and bushings are necessary. With the appropriate components, the 3AH vacuum circuit-breakers can be upgraded to the status of switchgear module.

2

3

Components The following components can be ordered: ■ Isolating contacts ■ Cup-type bushings with fixed mating contacts ■ Truck with/or without interlocks ■ Switchgear module (Dimensions as per Figs. 115 and 116)

Fig. 114: Switchgear module 12 kV, 25 kA, 1250 A

4 Front view

Side view

800

227

5

1019

Technical data and product range Components for 12 kV Up to 2500 A /to 40 kA /1 sec. For 800 mm switchgear panel width: With 3AH1 – 7.2/12 kV breaker 210 mm pole centre distance With 3AH5 – 12 kV breaker 210 mm pole centre distance

Components for 24 kV To 2500 A /to 25 kA /1 sec. For 1000 mm switchgear panel width: With 3AH1 – 24 kV breaker 275 mm pole centre distance With 3AH5 – 24 kV breaker 275 mm pole centre distance

6

945

7 Dimensions in mm Fig. 115: 12 kV switchgear module

8 Front view

On request: components for 15 kV

Side view 1000

295

1224

9

To 2500 A /to 40 kA /1 sec. For 800 mm switchgear panel width: With 3AH1 – 15 kV breaker 210 mm pole centre distance With 3AH5 – 17.5 kV breaker 210 mm pole centre distance

10 1030

Components for 36 kV To 1250 A /to 16 kA /1 sec. For 1200 mm switchgear panel width: With 3AH5 – 36 kV breaker 350 mm pole centre distance Fig. 113

Dimensions in mm Fig. 116: 24 kV switchgear module

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/81

Medium-Voltage Devices Type 3CG

1

2

3

4

5

6

Indoor vacuum switches type 3CG The 3CG vacuum switches are multipurpose switches conforming to IEC 60 265-1 and DIN VDE 0670 Part 301. With these, all loads can be switched without any restriction and with a high degree of reliability. The electrical and mechanical data are greater than for conventional switches. Moreover, the 3CG are maintenance free. The vacuum switch is therefore extremely economical. Vacuum switches are suitable for the following switching duties: ■ Overhead lines ■ Cables ■ Transformers ■ Motors ■ Capacitors ■ Switching under ground-fault conditions 3CG switches can be combined with HV HRC fuses up to 250 A. When installed in Siemens switchgear they comply with the specifications of IEC 60 420 and VDE 0670, Part 303. Maximum ratings of fuses on request.

7

Technical data Rated voltage U

[kV]

7.2

12

15

24

Rated lightning-impulse withstand voltage Ul,

[kV]

60

75

95

125

Rated short-circuit making current I ma

[kA]

50

50

50

40

Rated short-time current I m (3s)

[kA]

20

20

20

16

Rated normal current I n

[A]

800

800

800

800

Rated ring-main breaking current I c 1

[A]

800

800

800

800

Rated transformer breaking current

[A]

10

10

10

10

Rated capacitor breaking current

[A]

800

800

800

800

Rated cable-charging breaking current I c

[A]

63

63

63

63

Rated breaking current for stalled motors I d

[A]

2500

1600

1250

–

Transfer current according to IEC 60 420, [A] Inductive switching capacity (cosϕ ≤ 0.15)

5000

3000

2000

2000

630 63

630 63

630 63

630 63

63+800

63+800

63+800

63+800

10,000

10,000

10,000

10,000

Switching capacity under ground fault conditions: – Rated ground fault breaking current I e [A] – Rated cable-charging breaking [A] current – Rated cable charging breaking [A] current with superimposed load current Number of switching cycles with I n

8

Fig. 117: Ratings for vacuum switches type 3CG

9

10

Fig. 118: Vacuum switch type 3CG for 12 kV, 800 A

3/82

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Type 3CG

3CG, 7.2 and 12 kV

1 530 210

492 210

2

3 264

482

435

4

568

5

43 170

592 Dimensions in mm

6 3 CG, 24 kV

7

630 537 275

275

8

379

9

597 435

10

684 Dimensions in mm

708

43 170

Fig. 119: Dimensions of vacuum switch type 3CG (Examples)

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/83

Medium-Voltage Devices Type 3TL

1

2

3

4

5

6

7

8

Vacuum contactors Type 3TL The three-pole vacuum contactors type 3TL are for medium-voltage systems between 7.2 kV and 24 kV and incorporate a solenoid-operated mechanism for high switching frequency and unlimited closing duration.They are suitable for the operational switching of AC devices in indoor systems and can perform, for example, the following switching duties: ■ Switching of three-phase motors in AC-3 and AC-4 operation ■ Switching of transformers ■ Switching of capacitors ■ Switching of ohmic loads (e.g. arc furnaces) 3TL vacuum contactors have the following features: ■ Small dimensions ■ Long electrical life (up to 106 operating cycles) ■ Maintenance-free ■ Vertical or horizontal mounting The vacuum contactors comply with the standards for high-voltage AC contactors between 1 kV and 12 kV according to IEC Publication 60 470-1970 and DIN VDE 0660 Part 103. 3TL 6 and 3TL 8 contactors also comply with UL Standard 347. The vacuum contactors are available in different designs: ■ Type 3TL 6 with compact dimensions ■ Type 3TL 71 and 3TL 81 with slender design

220 mm

280 mm

375 mm 325 mm

390 mm

340 mm Fig. 120: Vacuum contactor type 3TL6 for fixed mounting

Fig. 121: Vacuum contactor type 3TL8 for fixed mounting

Technical data of the 3TL 6/7/8 vacuum contactor Vacuum contactor type

3TL 61

3TL 65

3TL 71

[kV] Rated normal voltage [Hz] Rated frequency [A] Rated normal current Switching capacity according to utilization category AC-4 (cos ϕ = 0.35) [A] Rated making current [A] Rated breaking current Mechanical life of contactor Switching cycles Mechanical life of vacuum interrupter Switching cycles Electrical life of vacuum interrupter (Rated normal current) Switching cycles

7.2 50/60 450

12 50/60 450

24 50/60 800

7.2 50/60 400

4500 3600

4500 3600

4500 3600

4000 3200

3 x 106

1 x 106

1 x 106

1 x 106

2 x 106

1 x 106

1 x 106

0.25 x 106

1 x 106

0.5 x 106

1 x 106

0.25 x 106

3TL 81

Fig. 122: Ratings for vacuum contactors type 3TL

9

10

3/84

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Type VS

Vacuum interrupters 1

Vacuum interrupters for the medium-voltage range are available from Siemens for all applications on the international market from 1 kV up to 40.5 kV.

2

Applications ■ ■ ■ ■ ■ ■ ■

Vacuum circuit-breakers Vacuum switches Vacuum contactors Transformer tap changers Circuit breakers for railway applications Autoreclosers Special applications, e.g. in nuclear fusion

3

4 Compact designs Siemens vacuum interrupters provide very high switching capacity in very compact dimensions: for example vacuum interrupters for 15 kV/40 kA with housing dimensions of 125 mm diameter by 161 mm length, or for 12 kV/13.1 kA with 68 mm diameter by 115 mm length. Consistant quality assurance Complete quality assurance (TQM and DIN/ISO 9001), rigorous material checking of every delivery and 100% tests of the interrupters for vacuum sealing assure reliable operation and the long life of Siemens vacuum interrupters. Environmental protection In the manufacture of our vacuum interrupters we only use environmentally compatible materials, such as copper, ceramics and high-grade steel. The manufacturing processes do not damage the environment. For example, no CFCs are used in production (fulfilling the Montreal agreement); the components are cleaned in a ultrasonic plant. During operation vacuum interrupters do not affect the environment and are themselves not affected by the environment.

5

Fig. 123: Vacuum interrupters from 1 kV up to 40.5 kV

6

Product range (extract) Interrupters for vacuum circuit-breakers Rated voltage Rated normal current Rated short-circuit breaking current

7 [kV] [A] [kA]

7.2

to 40.5

630

to 4000

12.5

to 80

8

Interrupters for vacuum contactors Rated voltage Rated normal current

[kV] [A]

1

to 24

400

to 800

9

Fig. 124a: Range of ratings for vacuum interrupters for CBs

10

Know-how for special applications If necessary, Siemens is prepared to supplement the wide standard program by way of tailored, customized concepts.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/85

Medium-Voltage Devices Type 3CJ1

1

2

3

4

Switch disconnectors type 3CJ1 Indoor switch disconnectors type 3CJ1 are multipurpose types and meet all the relevant standards both as the basic version and in combination with (make-proof) grounding switches. The 3CJ1 indoor switch-disconnectors have the following features: ■ A modular system with all important modules such as fuses, (make-proof) grounding switches, motor operating mechanism, shunt releases and auxiliary switches ■ Good dielectric properties even under difficult climatic conditions because of the exclusive use of standard post insulators for insulation against ground ■ No insulating partitions even with small phase spacings ■ Simple maintenance and inspection

5 Fig. 125: Switch disconnector type 3CJ1

6

Technical data

7

Rated voltage

[kV]

12

15

24

Rated short-time withstand current

[kA]

20

26

18

Rated short-circuit making current

[kA]

50

65

45

[A]

630

630

630

8 Rated normal current

Fig. 126: Ratings for switch disconnectors type 3CJ1

9

10

3/86

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Type 3D

Disconnecting and grounding switches type 3D

1

Disconnecting and grounding switches type 3D are suitable for indoor installations from 12 kV up to 36 kV. Disconnectors are mainly used to protect personnel working on equipment and must therefore be very reliable and safe. This is assured even under difficult climatic conditions. Disconnecting and grounding switches type 3D are supplied with a manual or motor drive operating mechanism.

2

3

4

5 Fig. 127: Disconnecting switch type 3DC

6

Technical data Rated voltage

[kV]

12

24

36

Rated short-time withstand current (1s)

[kA]

20 to 63

20 to 31.5

20 to 31.5

Rated short-circuit making current

[kA]

50 to 160

50 to 80

50 to 80

630 to 2500

630 to 2500

630 to 2500

7

8

Rated normal current

[A]

Fig. 128: Ratings for disconnectors type 3DC

9 Technical data Rated voltage

[kV]

Rated short-time withstand current (1s)

[kA]

Rated peak withstand current

[kA]

12

24

36

20 to 63

20 to 31.5

20 to 31.5

50 to 160

50 to 80

50 to 80

10

Fig. 129: Ratings for grounding switches type 3DE

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/87

Medium-Voltage Devices Type 3GD/3GH

1

2

3

4

5

6

7

HV HRC fuses type 3GD HV HRC (high-voltage high-rupturing-capacity) fuses are used for short-circuit protection in high-voltage switchgear. They protect switchgear and components, such as transformers, motors, capacitors, voltage transformers and cable feeders, from the dynamic and thermal effects of high shortcircuit currents by breaking them as they occur. The HV HRC fuse links can only be used to a limited degree as overload protection because they only operate with certainty when their minimum breaking current has already been exceeded. Up to this current the integrated thermal striker prevents a thermal overload on the fuse when used in circuit breaker/fuse combinations. Siemens HV HRC fuse links have the following features: ■ Use in indoor and outdoor installations ■ Nonaging because the fuse element is made of pure silver ■ Thermal tripping ■ Absolutely watertight ■ Low power loss With our 30 years of experience in the manufacture of HV HRC fuse links and with production and quality assurance that complies with DIN/ISO 9001, Siemens HV HRC fuse links meet the toughest demands for safety and reliability.

Fig. 130: HV HRC fuse type 3GD

Technical data Rated voltage

[kV]

7.2

12

24

36

Rated short-circuit breaking current

[kA]

63 to 80

40 to 63

31.5 to 40

31.5

6.3 to 250

6.3 to 160

6.3 to 100

6.3 to 40

Rated normal current

[A]

Fig. 131: Ratings for HV HRC fuse links type 3GD

Fuse-bases type 3GH 8

9

3GH fuse bases are used to accomodate HV HRC fuse links in switchgear. These fuse bases are suitable for: ■ Indoor installations ■ High air humidity ■ Occasional condensation 3GH HV HRC fuse bases are available as single-phase and three-phase versions. On request, a switching state indicator with an auxiliary switch can be installed.

10

Fig. 132: Fuse bases type 3GH with HV HRC fuse links

Technical data Rated voltage

[kV]

3.6/7.2

12

24

36

Peak withstand current

[kA]

44

44

44

44

[A]

400

400

400

400

Rated current

Fig. 133: Ratings for fuse bases type 3GH

3/88

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Medium-Voltage Devices Insulators and Bushings

Insulators: Post insulators type 3FA and bushings type 3FH/3FM Insulators (post insulators and bushings) are used to insulate live parts from one another and also fulfill mechanical carrying and supporting functions. The materials for insulators are various cast resins and porcelains. The use of these materials, which have proved themselves over many years of exposure to the roughest operating and ambient conditions, and the high quality standard to DIN/ISO 9001 assure the high degree of reliability of the insulators. Special ribbed forms ensure high electrical strength even when materials are deposited on the surface and occasional condensation is formed. Post insulators and bushings are manufactured in various designs for indoor and outdoor use depending on the application. Innovative solutions, such as the 3FA4 divider post insulator with an integrated expulsion-type arrester, provide optimum utility for the customer. Special designs are possible if requested by the customer.

1

2

3

4

5 Fig. 135: Post insulators type 3FA1/2

Technical data

6

Rated voltage

[kV]

3.6

12

24

36

Lightning-impulse withstand voltage

[kV]

60 to 65

65 to 90

100 to 145

145 to 190

Rated power-frequency withstand voltage

[kV]

27 to 40

35 to 50

55 to 75

75 to 105

Minimum failing load

[kN]

3.75 to 16

3.75 to 25

3.75 to 25

3.75 to 16

7

8

Fig. 136: Ratings for post insulators type 3FA1/2

9

L

U1

C1

L Conductor U Operating voltage U1 Partial voltage across C1 U2 Partial voltage across C2 and indicator

M

U U2

V

C2

A

C1 Coupling capacitance C2 Undercapacitance V Arrester A Indicator M Measuring socket

Fig. 134: Draw-lead bushing type 3FH5/6

Fig. 137: The principle of capacitive voltage indication with the 3FA4 divider post insulator

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

3/89

10

Medium-Voltage Devices Type 4M and Type 3E

1

2

3

4

5

Current and voltage transformers type 4M Measuring transformers are electrical devices that transform primary electrical quantities (currents and voltages) to proportional and in-phase quantities which are safe for connected equipment and operating personnel. The indoor post insulator current and voltage transformers of the block type have DIN-conformant dimensions and are used in air-insulated switchgear. A maximum of operational safety is assured even under difficult climatic conditions by the use of cycloalyphatic resin systems and proven cast-resin technology. Special customized versions (e.g. up to 3 cores for current transformers, switchable windings, capacitance layer for voltage indication) can be supplied on request. The program also includes cast-resin insulated-bushing current transformers and outdoor current and voltage transformers.

Fig. 138: Block current transformer type 4MA

Technical data Current transformers

Voltage transformers

Rated voltage

[kV]

12

24

36

Primary rated current

[A]

10 to 2500

10 to 2500

10 to 2500

80

80

80

Max. thermal rated [kA] short time current

6

Fig. 139: Outdoor voltage transformer type 4MS4

Sec. thermal limit current

[A]

12

24

36

5 to 10

5 to 13

8 to 17

Fig. 140: Ratings for current and voltage transformers

7 Surge arresters type 3E 8

9

10

Surge arresters have the function of protecting the insulation of installations or components from impermissible strain due to voltage surges. The product range includes: ■ Surge arresters for the protection of high-voltage motors and dry-type transformers. Range 3EF for cable networks up to 15 kV. ■ Plug-in surge arresters for the protection of distribution networks. Range 3EH2 for networks up to 42 kV. ■ Special arresters for the protection of rotary machines and furnaces. Range 3EE2 for networks up to 42 kV.

Fig. 141: Surge arrester type 3EE2

Technical data and product range 3EF

3EH2

3EE2

For networks of

[kV]

3.6 to 15

4.7 to 42

4.5 to 42

Rated discharge surge current

[kA]

1

10

10

Short-circuit current strength

[kA]

1 to 40

16

50 to 300

Fig. 142

3/90

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards SIVACON

Contents

Page

Introduction .................................... 4/2 Advantages .................................... 4/2 Technical data ............................... 4/3 Cubicle design ............................... 4/4 Busbar system ............................... 4/5 Installation designs ...................... 4/6 Circuit-breaker design ................. 4/6 Withdrawable-unit design .......... 4/7 In-line plug-in design ................. 4/13 In-line-type plug-in design 3NJ6 ................................. 4/14 Fixed-mounted design ................ 4/15 Communication with PROFIBUS®-DP ........................... 4/16 Frame and enclosure ................. 4/17 Forms of internal separation .... 4/18 Installation details ...................... 4/19

4

Low-Voltage Switchboards

Introduction 1

2

3

Low-voltage switchboards form the link between equipment for generation, transmission (cables, overhead lines) and transformation of electrical energy on the one hand, and the loads, such as motors, solenoid valves, actuators and devices for heating, lighting and air conditioning on the other. As the majority of applications are supplied with low voltage, the low-voltage switchboard is of special significance in both public supply systems and industrial plants.

Reliable power supplies are conditional on good availability, flexibility for processrelated modifications and high operating safety on the part of the switchboard. Power distribution in a system usually comes via a main switchboard (power control center or main distribution board) and a number of subdistribution boards or motor control centers (Fig. 1).

4

5

up to 4 MVA up to 690 V

Cable or busbar system

up to 6300 A

Incoming circuit-breaker

6

Main switchboard

LT

3-50 Hz

Circuit-breakers as feeders to the subdistribution boards

up to 5000 A

General The SIVACON low-voltage switchboard is an economical, practical and type-tested switchgear and controlgear assembly (Fig. 3), used for example in power engineering, in the chemical, oil and capital goods industries and in public and private building systems. It is notable for its good availability and high degree of personnel and system safety. It can be used on all power levels up to 6300 A: ■ As main switchboard (power control center or main distribution board) ■ As motor control centre ■ As subdistribution board. With the many combinations that the SIVACON modular design allows, a wide range of demands can be met both in fixed-mounted plug-in and in withdrawableunit design. All modules used are type-tested (TTA), i.e they comply with the following standards: ■ IEC 60439-1 ■ DIN EN 60439-1 ■ VDE 0660 Part 500 also ■ DIN VDE 0106 Part 100 ■ VDE 0660 Part 500, supplement 2, IEC 61641 (arcing faults) Certification DIN EN ISO 9001

Connecting cables

7 ST

ET

8

up to 630 A

Advantages of a SIVACON switchboard

FT

■ Type-tested standard modules ■ Space-saving base areas from

up to 630 A

up to 100 A

400 x 400 mm ■ Solid wall design for safe cubicle-

9

up to 630 A

Subdistribution board e. g. services (Lighting, heating, air conditioning, etc.)

up to 100 A

to-cubicle separation ■ High packing density with

up to 40 feeders per cubicle ■ Standard operator interface for all

withdrawable units ■ Test and disconnected position

M

10

M

M

M

Motor control center 1 in withdrawable-unit design for production/ manufacturing

LT ET FT ST

M

M

M

M

Motor control center 2 in withdrawable-unit design for production/ manufacturing

= Circuit-breaker design = Withdrawable-unit design = Fixed-mounted design = Plug-in design

with door closed

up to 100 A

■ Visible isolating gaps and points

of contact

Control

■ Alternative busbar positioning

at top or rear ■ Cable/bar connection from above

or below

Fig. 1: Typical low-voltage network in an industrial plant

4/2

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

Technical data at a glance 1 Rated insulation voltage (Ui)

1000 V

Rated operational voltage (Ue)

up to

690 V

up to up to up to

6300 A 250 kA 100 kA

2

Busbar currents (3- and 4-pole): Horizontal main busbars Rated current Rated impulse withstand current (Ipk) Rated short-time withstand current (Icw) Vertical busbars

3

for circuit-breakers design

4

See horizontal main busbars for fixed-mounted design / plug-in design Rated current Rated impulse withstand current (Ipk) Rated short-time withstand current (Icw)

up to 2000 A up to 110 kA up to 50 kA*

5

up to 1000 A up to 143 kA up to 65 kA*

6

for withdrawable-unit design Rated current Rated impulse withstand current (Ipk) Rated short-time withstand current (Icw) Device rated Circuit-breakers Cable feeders Motor feeders

up to up to up to

Power loss per cubicle with combination of various cubicles (Pv) Degree of protection to IEC 60529, EN 60529

6300 A 1600 A

7

630 A

approx. 600 W** IP 20 up to IP 54

* Rated conditional short-circuit current Icc up to 100 kA ** Mean value at simultaneity factor of all feeders of 0.6

8

Fig. 2

1

2

3

4

9

1 Circuit-breaker-design cubicle with withdrawable circuit-breaker 3WN, 1600 A

2 Withdrawable-unit-design cubicle

10

with miniature and normal withdrawable units up to 250 kW

3 Plug-in design cubicle with in-line modules and plug-in fuse strips 3NJ6

4 Fixed-mounted-design cubicle with modular function units

Fig. 3: SIVACON low-voltage switchboard

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

4/3

Low-Voltage Switchboards

Cubicle design 1

2

3

4

5

6

7

The cubicle is structured in modular grid based on one modular spacing (1 M) corresponding to 175 mm. The effective device installation space with a height of 1750 mm therefore represents a height of 10 M. The top and bottom space each has a height of 225 mm (Fig. 5). A cubicle is subdivided into four function compartments: ■ Busbar compartment ■ Device compartment ■ Cable connection compartment ■ Cross-wiring compartment In 400 mm deep cubicles, the busbar compartment is at the top; in 600 mm deep cubicles it is at the rear. In double-front systems (1000 mm depth) and in a power control center (1200 mm depth), the busbar compartment is located centrally. The switching device compartment accommodates switchgear and auxiliary equipment. The cable connection compartment is located on the right-hand side of the cubicle. With circuit-breaker design, however, it is below the switching device compartment (Fig. 4). The cross-wiring compartment is located at the top front and is provided for leading control and loop lines from cubicle to cubicle.

400

600 400

600

400 400 400

8

9

10 Busbar compartment Device compartment

Cable connection compartment Cross-wiring compartment

Dimensions in mm

Fig. 4: Cubicle design

4/4

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

Busbar system Together with the PEN or PE busbars, and if applicable the N busbars, the phase conductor busbars L1, L2 and L3 form the busbar system of a switchboard. One or more distribution buses and/or incoming and outgoing feeders can be connected to a horizontal main busbar. Depending on requirements, this main busbar passes through several cubicles and can be linked with another main busbar via a coupling. A vertical distribution busbar is connected with the main busbar and supplies outgoing feeders within a cubicle. In a 400 mm deep cubicle (Fig. 5a) the phase conductors of the main busbar are always at the top; the PEN or PE and N conductors are always at the bottom. The maximum rated current at 35 °C is 1965 A (non-ventilated), and 2250 A (ventilated); the maximum short-circuit strength is Ipk = 110 kA or Icw = 50 kA, respectively. In single-front systems with 600 mm cubicle depth (Fig. 5b), the main busbars are behind the switching device compartment. In double-front systems of 1000 mm depth (Fig. 5c), they are between the two switching device compartments (central). The phase conductors can be arranged at the top or bottom; PEN, PE and N conductors are always at the bottom. The maximum rated current is at 35 °C 3250 A (non-ventilated) or 3500 A (ventilated); Ipk = 250 kA or Icw = 100 kA, respectively. In 1200 mm deep systems (power control center) (Fig. 5d) the conductors are arranged as for double-front systems, but in duplicate; the phase conductors are always at the top. The maximum rated current at 35 °C is 4850 A (non-ventilated) or 6300 A (ventilated); Ipk = 220 kA, Icw = 100 kA.

1 Top space

Switching device compartment

2 225

225

3 10 x 175

10 x 175

2200

4

225

225

5

200 400

400

Bottom space a)

b)

6

7 225

225

8 10 x 175

2200

10 x 175

2200

9 225

225

400 200 400

c)

400

400

400

10

d)

Dimensions in mm

Fig. 5: Modular grid and location of main busbars

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

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Low-Voltage Switchboards

Installation designs 1

2

3

4

5

6

7

The following designs are available for the duties specified: ■ Circuit-breaker design ■ Withdrawable-unit design ■ Plug-in design ■ Fixed-mounted design

Circuit-breaker design Distribution boards for substantial energy requirements are generally followed by a number of subdistribution boards and loads. Particular demands are therefore made in terms of long-term reliability and safety. That is to say, ”supply“, ”coupling“ and ”feeder“ functions must be reliably available over long periods of time. Maintenance and testing must not involve long standstill times. The circuit-breaker design components meet these requirements. The circuit-breaker cubicles have separate function spaces for a switching device compartment, auxiliary equipment compartment and cable/busbar connection compartment (Fig. 7). The auxiliary equipment compartment is above the switching device compartment. The cable or busbar connection compartment is located below. With supply from above, the arrangement is a like a mirror image. The cubicle width is determined by the breaker rated current.

8

9

Breaker rated current [A]

Cubicle width

IN to 1600 IN to 2500 IN to 3200 IN to 6300

400/500 600 800 1000

[mm]

Fig. 6

Circuit-breaker design 3WN

10

The 3WN circuit-breakers in withdrawableunit or fixed-mounted design are used for incoming supply, outgoing feeders and couplings (longitudinal and transverse). The operational current can be shown on an LCD display in the control panel; there is consequently no need for an ammeter or current transformer.

4/6

Fig. 7: Circuit-breaker cubicle with withdrawable circuit-breaker 3WN, 1600 A rated current

The high short-time current-carrying capacity for time-graded short-circuit protection (up to 500 ms) assures reliable operation of sections of the switchboard not affected by a short circuit. With the aid of short-time grading control for very brief delay times (50 ms), the stresses and damage suffered by a switchboard in the event of a short-circuit can be substantially minimized, regardless of the preset delay time of the switching device concerned. The withdrawable circuit-breaker has three positions between which it can be moved with the aid of a crank or spindle mechanism. In the connected position the main and auxiliary contacts are closed.

In the test position the auxiliary contacts are closed. In the disconnected position both main and auxiliary contacts are open. Mechanical interlocks ensure that, in the process of moving from one position to another, the circuit-breaker always reaches the OPEN state or that closing is not possible when the breaker is between two positions. The circuit-breaker is always moved with the door closed. The actual position in which it is can be telecommunicated via a signaling switch. A kit, switch or withdrawable unit can be used for grounding and short-circuiting.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

Withdrawable-unit design A major feature of withdrawable-unit design is removability and ease of replacement of equipment combinations under operating conditions, i.e. a switchboard can be adapted to process-related modifications without having to be shut down. Withdrawable-unit design is used therefore mainly for switching and control of motors (Fig. 8). Withdrawable units

A distinction is made between miniature (sizes 1/4 and 1/2) and normal withdrawable units (sizes 1, 2, 3 and 4) (Fig. 9). The normal withdrawable unit of size 1 has a height of one modular spacing (175 mm) and can, with the use of a miniature withdrawable unit adapter, be replaced by 4 withdrawable units of size 1/4 or 2 units of size 1/2. The withdrawable units of sizes 2, 3 and 4 have a height of 2, 3 and 4 modular spacings, respectively. The maximum complement of a cubicle is, for example, 10 full-size withdrawable units of size 1 or 40 miniature withdrawable units of size 1/4 .

1

2

3

The equipment of the main circuit of an outgoing feeder and the relevant auxiliary equipment are integrated as a function unit in a withdrawable unit, which can be easily accommodated in a cubicle. In basic state, all equipment and movable parts are within the withdrawable unit contours and thereby protected from damage. The facility for equipping the withdrawable units from the rear allows plenty of space for auxiliary devices. Measuring instruments, indicator lights, pushbuttons, etc. are located on a hinged instrument panel, such that settings (e.g. on the overload relay) can be easily performed during operation.

4

5

6

7

8

9

10

Fig. 8: High packing density with up to 40 feeders per cubicle

Fig. 9: SIVACON withdrawable units size 1, size 1/4 and 1/2

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

4/7

Low-Voltage Switchboards

Moving isolating contact system

1

L3 L2 L1 N

Connected position

L3 L2 L1 N

Disconnected position

2

3

4

5

6 L3 L2 L1 N

7

For main and auxiliary circuits the withdrawable units are equipped with a moving isolating contact system. It has contacts on both the incoming and outgoing side; they can be moved by handcrank such that they come laterally out of the withdrawable unit and engage with the fixed contacts in the cubicle. On miniature withdrawable units the isolating contact system moves upwards into the miniature withdrawable unit adapter. A distinction is made between connected, disconnected and test position (Fig. 10). In the connected position both main and auxiliary contacts are closed; in the disconnected position they are open. The test position allows testing of the withdrawable unit for proper function in no-load (cold) state, in which the main contacts are open, but the auxiliary contacts are closed for the incoming control voltage. In all three positions the doors are closed and the withdrawable unit mechanically connected with the switchboard. This assures optimal safety for personnel and the degree of protection is upheld. Movement from the connected into the test position and vice-versa always passes through the disconnected position; this assures that all contactors drop out. Operating error protection Integrated maloperation protection in each withdrawable unit reliably prevents moving of the isolating contacts with the main circuit-breaker ”CLOSED“ (handcrank cannot be attached) (Fig. 11).

Test position

8 Fig. 10: Withdrawable-unit principle

9

10

Fig. 11: Operating error protection prevents travel of the isolating contacts when the master switch is “ON”

4/8

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

Indicating and signaling

AZNV

Test

AZNV/Test 21

- S21 - X19

- X19

- X19

22

21

21

- Q1

- S21

- Q1

Compt.

- S21

- S20

22

WU

COM

WU

The current position of a withdrawable unit is clearly indicated on the instrument panel. Such signals as ”feeder not available“ (AZNV), ”test“ and ”AZNV and test“ can be given by additional alarm switches. The alarm switch in the compartment (S21) is a limit switch of NC design; that in the withdrawable unit (S20) is of NO design. Both are actuated by the main isolating contacts of the withdrawable unit (Fig. 12).

WU

2

3

22 AZNV

Compt.

1

Test Compt.

4 X19 = Auxiliary isolating contact S20 = Alarm switch in withdrawable unit* S21 = Alarm switch in compartment* WU = Withdrawable unit Compt. = Compartment

5

*actuated by main isolating contact

Main isolating contact

Aux. isolating contact

6

7 In withdrawable unit - S 20 1 NO

In compartment - S 21 1 NC

8 Connected

9 * Disconnected

10 Test

*No signal, as auxiliary isolating contact open Fig. 12: Circuitry and position of main and auxiliary contacts

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

4/9

Low-Voltage Switchboards

Vertical distribution bus (plug-on bus)

1

2

The vertical plug-on bus with the phase conductors L1, L2 and L3 is located on the left-hand side of the cubicle and features safe-to-touch tap openings (Fig. 13). The vertical PE, PEN and N busbars are on the right-hand side of the cubicle in a separate, 400 mm wide cable connection compartment, equipped with variable cable brackets.

3

4

Fig. 13: Arcing fault-protected plug-on bar system embedded in the left of the cubicle

5 Rated currents – fused and withdrawable unit sizes of cable feeders

Device

Rated current

Type

[A]

D306 3KL50 3KL52 3KL53 3KL55 3KL57 3KL61

35 63 125 160 250 400 630

1/4 / 1/2 1 1 2 2 2 3

Device

Rated current

Withdrawable unit size

Type

[A]

3RV101 3RV102 3RV103 3RV104 3VF3 3VF4 3VF5 3VF6

12 25 50 160 160 250 400 630

6

7

8

9

Rated currents – non-fused and withdrawable unit sizes of cable feeders

10 I

Withdrawable unit size

1/4 / 1/2 1/4 / 1/2 / 1 1/2 / 1 1 1 2 2 4

Fig. 14

4/10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

Power ratings – fused and withdrawable unit sizes of motor feeders

1

FVNR

FVR

Star-delta starters

2

3

4

5 Full-voltage non-reversing (FVNR) motor starters Normal-duty start [kW]

Full-voltage non-reversing (FVNR) motor starters Heavy-duty start [kW]

Full-voltage reversing (FVR) motor starters Reversing circuit [kW]

Star-delta starters [kW]

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

11 18.5 22 75 160 250 – –

11 22 22 90 200 355

11 22 37 90 160 500

7.5 15 22 45 90 160 – –

7.5 15 30 55 132 200

11 22 37 90 132 375

5.5 18.5 22 45 110 250 – –

5.5 22 22 55 132 315

5.5 22 22 55 160 375

– – 30 55 132 – 250 355

– – 37 75 160 – 315 355

– – 55 90 160 – 400 500

Withdrawable unit size

6

1/4 1/2 1 2 3 4 3+3 4+4

7

8

Fig. 15

9

10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

4/11

Low-Voltage Switchboards

1

Power ratings – non-fused with overload relay and withdrawable unit sizes of motor feeders

FVNR

FVR

Star-delta starters

2

3

I

I

I

4

5 Coordination type 1

6

7

8

Full-voltage non-reversing (FVNR) motor starters Normal-duty start [kW]

Full-voltage non-reversing (FVNR) motor starters Heavy-duty start [kW]

Full-voltage reversing (FVR) motor starters Reversing circuit [kW]

Star-delta starters [kW]

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

11 18.5 22 75 160 250

11

– – – – – –

4 11 11 37 132 160

3 15 15 45 160 200

– – – – – –

5.5

5.5 11 30 90 200 315

– – – – – –

– – 22 55 110 200

– – 30 75 132 250

– – – – – –

18.5 30 90 200 250

11 22 75 160 250

Withdrawable unit size

1/4 1/2 1 2 3 4

Coordination type 2

9

10

Full-voltage non-reversing (FVNR) motor starters Normal-duty start [kW]

Full-voltage non-reversing (FVNR) motor starters Heavy-duty start [kW]

Full-voltage reversing (FVR) motor starters Reversing circuit [kW]

Star-delta starters [kW]

400 V

500 V

690 V

400 V

7.5 18.5 22 75 160 250

7.5 18.5 30 90 200 315

– – – – –

4 11 11 37 132 160

Withdrawable unit size

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

0.37 11 15 45 160 200

– – – – – –

0.55 7.5 22 55 160 250

0.75 7.5 30 75 200 315

– – – – – –

– – 22 55 110 160

– – 30 75 132 100

– – – – – –

1/4 1/2 1 2 3 4

Fig. 16

4/12

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

In-line plug-in design The in-line plug-in design represents a lowpriced alternative to both the classic fixedmounted and the convenient withdrawable unit design. By virtue of the supply-side plug-in contact, the modules provide the facility for quick interchangeability without the switchboard having to be isolated. This design is therefore used wherever changing requirements are imposed on operation, if for example motor ratings have to be changed or new loads connected. In-line plug-in modules, a cost-effective, compact design for: ■ Load outgoing feeders up to 45 kW ■ 3RV outgoing circuit-breaker units up to 100 A The modules are fitted with the new SIRIUSTM 3R switching devices. The compact overall width of the SIRIUS 3R devices, as well as the facility for lining them up with connecting modules, are particulary noticeable in the extremely narrow construction of the in-line modules. A lateral guide rail in the cubicle facilitates handling when replacing a module and at the same time ensures positive contact with the plug-in bus system.

Rated currents – non fused and modulheight of cable feeders

1 Rated current

Modulheight

Type

[A]

[mm]

3RV101 3RV102 3RV103 3RV104

12 25 50 100

50 50 100 100

Device

I

2

3

Fig. 18

4

Power ratings – non-fused with overload relay and module height of motor feeders

FVNR

FVR

5

I

6

I

7

Coordination type 1

Full-voltage non-reversing (FVNR) motor starters Normal-duty start [kW]

Full-voltage reversing (FVR) motor starters Reversing circuit [kW]

400 V 11 45 –

400 V – 11 45

Modulheight [mm]

9

50 100 200

Coordination type 2

Fig. 17: In-line plug-in design combined with plug-in fuse strips 3NJ6

10

Full-voltage non-reversing (FVNR) motor starters Normal-duty start [kW]

Full-voltage reversing (FVR) motor starters Reversing circuit [kW]

400 V 7.5 45 –

400 V – 7.5 45

Modulheight [mm]

50 100 200

Fig. 19

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

8

4/13

Low-Voltage Switchboards

In-line-type plug-in design 3NJ6 1

2

3

4

5

6

7

8

9

In-line-type switching devices allow spacesaving installation of cable feeders in a cubicle and are particularly notable for their compact design (Fig. 20). The in-line-type switching devices feature plug-in contacts on the incoming side. They are alternatively available for cable feeders up to 630 A as: ■ Fuse module ■ Fuse-switch disconnectors (single-break) ■ Fuse-switch disconnectors (double-break) with or without solid-state fuse monitoring ■ Switch disconnectors

The single- or double-break in-line-type switching devices allow fuse changing in dead state. The main switch is actuated by pulling a vertical handle to the side. The modular design allows quick reequipping and easy replacement of in-line-type switching devices under operating conditions. The in-line-type switching devices have a height of 50 mm, 100 mm or 200 mm. A cubicle can consequently be equipped with up to 35 in-line-type switching devices. Vertical distribution bus (plug-on bus) The vertical plug-on bus with the phase conductors L1, L2 and L3 is located at the back in the cubicle and can be additionally fitted with a shock-hazard protection. The vertical PE, PEN and N busbars are on the right-hand side of the cubicle in a separate, 400 mm wide cable connection compartment, equipped with variable cable brackets.

Fig. 20: Cubicle with in-line-type switching devices

Fuse-switch disconnector (single break)

10

Device

Rated current

In-linetype size

Type

[A]

Height [mm]

3NJ6110

160

50

3NJ6120

250

100

3NJ6140

400

200

3NJ6160

630

200

Fig. 21: Rated currents and installation data of in-line-type switching devices

4/14

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

Fixed-mounted design 1

In certain applications, e.g. in building installation systems, either there is no need to replace components under operating conditions or short standstill times do not result in exceptional costs. In such cases the fixed-mounted design (Fig. 22) offers excellent economy, high reliability and flexibility by virtue of: ■ Any combination of modular function units ■ Easy replacement of function units after deenergizing the switchboard ■ Brief modification or standstill times by virtue of lateral vertical cubicle busbars ■ Add-on components for subdivision and even compartmentalization in accordance with requirements.

2

3

4

Modular function units

5

The modular function units enable versatile and efficient installation, above all whenever operationally required changes or adaptations to new load data are necessary (Fig. 23). The subracks can be equipped as required with switching devices or combinations thereof; the function units can be combined as required within one cubicle. When the function modules are fitted in the cubicle they are first attached in the openings provided and then bolted to the cubicle. This securing system enables uncomplicated ”one-man assembly“.

6

7

Vertical distribution bus (cubicle busbar) The vertical cubicle busbar with the phase conductors L1, L2 and L3 is fastened to the left-hand side wall of the cubicle and offers many connection facilities (without the need for drilling or perforation) for cables and bars. It can be subdivided at the top or bottom once per cubicle (for group circuits or couplings). The connections are easily accessible and therefore equally easy to check. A transparent shock-hazard protection allows visual inspection and assures a very high degree of personnel safety. The vertical PE, PEN and N busbars are on the right-hand side of the cubicle in a separate, up to 400 mm wide cable connection compartment, equipped with variable cable brackets.

8 Fig. 22: Variable fixed-mounted design

9

10

Fig. 23: Fused modular function unit with direct protection, 45 kW

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

4/15

Low-Voltage Switchboards

1

2

3

4

Communication with PROFIBUS® -DP With SIMOCODE®-DP for motor and cable feeders and the interface DP/3WN for circuit-breakers type 3WN, SIVACON offers an economical possibility of exchanging data with automation systems. The widespread standardized, cross-manufacturer-PROFIBUS®-DP serves as the bus system, offering links to a very diverse range of programmable controllers. ■ Easy installation planning ■ Saving in wiring Communication-capable circuit-breaker 3WN (Fig. 25) ■ Remote-control for opening and closing ■ Remote diagnostics for preventive main-

tenance

5

6

■ Signalling of operating states ■ Transmission of current values e.g. for

Fig. 25: 3WN circuit-breaker

Fig. 26: SIMOCODE-DP in size 1/4 withdrawable unit

Fig. 27: AS-interface modules 41

power management Communication-capable motor protection and control device SIMOCODE-DP (Fig. 26) ■ ■ ■ ■

7

Fig. 24

Integrated full motor protection Extensive control functions Convenient diagnostics possibilities Autonomous operation of each feeder via an operator control block

AS-interface (Fig. 27) ■ Status messages via AS-I modules

8

(On/Off/Control)

9

10

4/16

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

Frame and enclosure The galvanized SIVACON cubicle frames are of solid wall design and ensure reliable cubicle-to-cubicle separation. The enclosure is made of powder-coated steel sheets (Fig. 28 and 29). A cubicle front features one or more doors, depending on requirements and cubicle type. These doors are of 2 mm thick, powder-coated sheet steel and are hinged on the right or left (attached to the frame). Spring-loaded door locks prevent the doors from flying open unintentionally, and also ensure safe pressure equalization in the event of an arcing fault.

1

Top busbar system

2

3

4

Degree of protection (against foreign bodies/water, and personnel safety) A distinction is made between ventilated and non-ventilated cubicles. Ventilated cubicles are provided with slits in the base space door and in the top plate and attain degree of protection in relation to the operating area of IP 20/21 or IP 40/41, respectively. Non-ventilated cubicles attain degree of protection IP 54. In relation to the cable compartment, degree of protection IP 00 or IP 40, is generally attained.

5 Rear busbar system

6 Fig. 28: Rear and top busbar system

Fig. 29: Device compartment can be separated from interconnected busbar

7

Cubicle dimensions and average weights

Height [mm]

Width [mm]

Depth [mm]

500 600 500 600 600 800 1000 1000

400

Rated current [A]

Approx. weight [kg]

up to 1600 up to 2000 up to 1600 up to 1600 up to 2500 up to 3200 up to 4000 up to 6300

285 390 325 335 440 540 700 1200

Circuit-breaker design 2200

8 600

1200

9

Withdrawable-unit design/plug-in design 2200

10

1000

400 600 1000

420 480 690

1000

400 600 1000

320 380 550

Fixed-mounted design 2200

Fig. 30: Cubicle dimensions and average weights

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

4/17

Low-Voltage Switchboards

Form of internal separation 1

Form 1 In accordance with IEC 60439-1, (Fig. 32) Depending on requirements, the function compartments can be subdivided as per the following table:

Functional unit

1

2

3

4

4

4 4

Form 1 2a 2b 3a 3b 4a 4b

4

5

1 2 3 4

4

2

3

2

Terminal for external conductors Main busbar Busbar Incoming circuit Outgoing circuit

4 4

Circuitbreaker design Withdrawableunit design

Form 2a

Form 2b

1

2

1

2

2

4

Plug-in design – 3 NJ6 – In-line

3

4

2 4

4

4

3

4

4

4

4

4 4

6

7

Fixedmounted design – Modular – Compensation Fig. 31

4

4

4

Form 3a

Form 3b

1

2

1

2

2

4 3

4

2 4

4

4

3

4

4

4

4

4

8

4

4

4

4

9 Form 4a

Form 4b

1

2

10

1

2

2

4 3

4

4

4

2 4

4

3

4

4

4 4

4 4

4 4

Fig. 32: Forms of internal separation to IEC 60439-1

4/18

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Low-Voltage Switchboards

Installation details

Floor penetrations

Transport units

The cubicles feature floor penetrations for leading in cables for connection, or for an incoming supply from below (Fig. 35).

For transport purposes, individual cubicles of a switchboard are combined to form a transport unit, up to a maximum length of 2400 mm. The transport base is 200 mm longer than the transport unit and is 190 mm high. The transport base depth is:

Cubicle depth 400 mm 25

[mm]

Transport base depth [mm]

400

600 1000 1200

2

Diameter 14.1

323

Cubicle depth

1

400

215

3

75

38.5 Cubicle width - 100

900 1050 1460 1660

4

Cubicle width Fig. 33

Cubicle depth 600 mm If the busbar is at the top, the main busbars between two transport units are connected via lugs which are bolted to the busbar system. If the busbar is at the rear, the individual bars can be bolted together via connection elements, as the conductors of the right-hand transport unit are offset to the left and protrude beyond the cubicle edge. Mounting

25

Diameter 14.1

523 323

6

250 600 75

38.5

Cubicle depths 400 mm and 600 mm: ■ Wall- or ■ Floor-mounting Cubicle depths 1000 mm and 1200 mm: ■ Floor-mounting The following minimum clearances between the switchboard and any obstacles must be observed:

5

Cubicle width - 100

7

Cubicle width

Cubicle depth 1000 mm, 1200 mm 25

8

Diameter 14.1 75

Clearances

250

9 100 mm

75 mm

100 mm

1000 or 1200

Cubicle depth - 77

Switchboard

75

38.5 Fig. 34

10

250

Cubicle width - 100 Cubicle width

There must be a minimum clearance of 400 mm between the top and sides of the cubicle and any obstacles.

Free space for cables and bar penetrations Fig. 35: Floor penetrations

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

4/19

Low-Voltage Switchboards

Operating and maintenance gangways All doors of a SIVACON switchboard can be fitted such that they close in the direction of an escape route or emergency exit. If they are fitted differently, care must be taken that when doors are open, there is a minimum gangway of 500 mm (Fig. 36). In general, the door width must be taken into account, i.e. a door must open through at least 90°. (In circuit-breaker and fixedmounted designs the maximum door width is 1000 mm.) If a lifting truck is used to install a circuitbreaker, the gangway widths must suit the dimensions of the lifting truck.

1

2

20001)

3

600

4

700

700

600 700

700

Dimensions of lifting truck [mm] 1)

Minimum gangway height under covers or enclosures

Height Width Depth

5

2000 680 920

Minimum gangway width [mm] Approx.

6

1500

Fig. 37

7 Min. gangway width Escape route 600 or 700 mm

Free min. width 500 mm1)

2)

8

9

10

1) Where

switchboard fronts face each other, narrowing of the gangway as a result of open doors (i.e. doors that do not close in the direction of the escape route) is reckoned with only on one side 2) Note door widths, i.e. it must be possible to open the door through at least 90° Dimensions in mm

Fig. 36: Reduced gangways in area of open doors

4/20

For further information please contact: Fax: ++ 49 - 3 41- 4 47 04 00 www.ad.siemens.de

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Transformers

Contents

Page

Introduction ....................................... 5/2 Product Range .................................. 5/3 Electrical Design .............................. 5/4 Transformer Loss Evaluation ......... 5/6 Mechanical Design ......................... 5/8 Connection Systems ....................... 5/9 Accessories and Protective Devices ........................ 5/11 Technical Data Distribution Transformers ............ 5/13 Technical Data Power Transformers ...................... 5/18 On-load Tap Changers .................. 5/26 Cast-resin Dry-type Transformers, GEAFOL .................. 5/27 Technical Data GEAFOL Cast-resin Dry-type Transformers .................. 5/31 Special Transformers .................... 5/35

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Introduction

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2

3

4

5

6

Transformers are one of the primary components for the transmission and distribution of electrical energy. Their design results mainly from the range of application, the construction, the rated power and the voltage level. The scope of transformer types starts with generator transformers and ends with distribution transformers. Transformers which are directly connected to the generator of the power station are called generator transformers. Their power range goes up to far above 1000 MVA. Their voltage range extends to approx. 1500 kV. The connection between the different highvoltage system levels is made via network transformers (network interconnecting transformers). Their power range exceeds 1000 MVA. The voltage range exceeds 1500 kV. Distribution transformers are within the range from 50 to 2500 kVA and max. 36 kV. In the last step, they distribute the electrical energy to the consumers by feeding from the high-voltage into the low-voltage distribution network. These are designed either as liquid-filled or as dry-type transformers. Transformers with a rated power up to 2.5 MVA and a voltage up to 36 kV are referred to as distribution transformers; all transformers of higher ratings are classified as power transformers.

7

In addition, there are various specialpurpose transformers such as converter transformers, which can be both in the range of power transformers and in the range of distribution transformers as far as rated power and rated voltage are concerned. As special elements for network stabilization, arc-suppression coils and compensating reactors are available. Arc-suppression coils compensate the capacitive current flowing through a ground fault and thus guarantee uninterrupted energy supply. Compensating reactors compensate the capacitive power of the cable networks and reduce overvoltages in case of load rejection; the economic efficiency and stablility of the power transmission are improved. The general overview of our manufacturing/delivery program is shown in the table ”Product Range“.

The transformers comply with the relevant VDE specifications, i.e. DIN VDE 0532 ”Transformers and reactors“ and the ”Technical conditions of supply for threephase transformers“ issued by VDEW and ZVEI. Therefore they also satisfy the requirements of IEC Publication 76, Parts 1 to 5 together with the standards and specifications (HD and EN) of the European Union (EU). Enquiries should be directed to the manufacturer where other standards and specifications are concerned. Only the US (ANSI/NEMA) and Canadian (CSA) standards differ from IEC by any substantial degree. A design according to these standards is also possible. Important additional standards ■ DIN 42 500, HD 428: oil-immersed

Rated power

Max. operating voltage

[MVA]

[kV]

Figs. on page

■

5/13– 5/17

2.5–3000 36–1500 Power transformers

5/18– 5/25

≤ 36

■ ■

0.05–2.5 ≤ 36 Oil distribution transformers

0.10–20 GEAFOLcast-resin transformers

8

Standards and specifications, general

5/27– 5/34

■ ■ ■ ■ ■

three-phase distribution transformers 50–2500 kVA DIN 42 504: oil-immersed three-phase transformers 2–10 MVA DIN 42 508: oil-immersed three-phase transformers 12.5–80 MVA DIN 42 523, HD 538: three-phase dry-type transformers 100–2500 kVA DIN 45 635 T30: noise level IEC 289: reactance coils and neutral grounding transformers IEC 551: measurement of noise level IEC 726: dry-type transformers RAL: coating/varnish

Fig. 1: Transformer types

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Product Range

Oil-immersed distribution transformers, TUMETIC, TUNORMA

50 to 2 500 kVA, highest voltage for equipment up to 36 kV, with copper or aluminum windings, hermetically sealed (TUMETIC®) or with conservator (TUNORMA®) of three- or single-phase design

1

2 Generator and power transformers

Above 2.5 MVA up to more than 1000 MVA, above 30 kV up to 1500 kV (system and system interconnecting transformers, with separate windings or auto-connected), with on-load tap changers or off-circuit tap changers, of three- or single-phase design

3

Cast-resin distribution and power transformers GEAFOL

100 kVA to more than 20 MVA, highest voltage for equipment up to 36 kV, of three- or single-phase design GEAFOL®-SL substations

Special transformers for industry, traction and HVDC transmission systems

Furnace and converter transformers Traction transformers mounted on rolling stock and appropriate on-load tap-changers Substation transformers for traction systems Transformers for train heating and point heating Transformers for HVDC transmission systems Transformers for audio frequencies in power supply systems Three-phase neutral electromagnetic couplers and grounding transformers Ignition transformers

4

5

6

7 Reactors

Accessories

Liquid-immersed shunt and current-limiting reactors up to the highest rated powers Reactors for HVDC transmission systems

8

Buchholz relays, oil testing equipment, oil flow indicators and other monitoring devices Fan control cabinets, control cabinets for parallel operation and automatic voltage control Sensors (PTC, Pt 100)

9

10 Service

Advisory services for transformer specifications Organization, coordination and supervision of transportation Supervision of assembly and commissioning Service/inspection troubleshooting services Training of customer personnel Investigation and assessment of oil problems

Fig. 2

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Electrical Design

Power ratings and type of cooling

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2

3

All power ratings in this guide are the product of rated voltage (times phase-factor for three-phase transformers) and rated current of the line side winding (at center tap, if several taps are provided), expressed in kVA or MVA, as defined in IEC 76-1. If only one power rating and no cooling method are shown, natural oil-air cooling (ONAN or OA) is implied for oil-immersed transformers. If two ratings are shown, forced-air cooling (ONAF or FA) in one or two steps is applicable. For cast resin transformers, natural air cooling (AN) is standard. Forced air cooling (AF) is also applicable.

I

Dy1

5

6

7

8

9

1

ii

III

i

iii

II III

I

Dy5

ii

I

iii i

iii

ii

II III

5

II

ii

Yd5

Temperature rise

II

i 5

In accordance with IEC-76 the standard temperature rise for oil-immersed power and distribution transformers is: ■ 65 K average winding temperature (measured by the resistance method) ■ 60 K top oil temperature (measured by thermometer) The standard temperature rise for Siemens cast-resin transformers is ■ 100 K (insulation class F) at HV and LV winding. Whereby the standard ambient temperatures are defined as follows: ■ 40 °C maximum temperature, ■ 30 °C average on any one day, ■ 20 °C average in any one year, ■ –25 °C lowest temperature outdoors, ■ –5 °C lowest temperature indoors. Higher ambient temperatures require a corresponding reduction in temperature rise, and thus affect price or rated power as follows: ■ 1.5% surcharge for each 1 K above standard temperature conditions, or ■ 1.0% reduction of rated power for each 1 K above standard temperature conditions. These adjustment factors are applicable up to 15 K above standard temperature conditions.

10

11

Dy11

I

Yd11

The transformers are suitable for operation at altitudes up to 1000 meters above sea level. Site altitudes above 1000 m necessitate the use of special designs and an increase/or a reduction of the transformer ratings as follows (approximate values):

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I 11

i

i

ii III

iii

ii

II

III

iii

II

Fig. 3: Most commonly used vector groups

■ 2% increase for every 500 m altitude (or

part there of) in excess of 1000 m, or ■ 2% reduction of rated power for each 500 m altitude (or part there of) in excess of 1000 m. Transformer losses and efficiencies Losses and efficiencies stated in this guide are average values for guidance only. They are applicable if no loss evaluation figure is stated in the inquiry (see following chapter) and they are subject to the tolerances stated in IEC 76-1, namely +10% of the total losses, or +15% of each component loss, provided that the tolerance for the total losses is not exceeded. If optimized and/or guaranteed losses without tolerances are required, this must be stated in the inquiry.

Altitude of installation

Ohne Namen-1

I

i

iii

III

4

Yd1

1

Connections and vector groups Distribution transformers The transformers listed in this guide are all three-phase transformers with one set of windings connected in star (wye) and the other one in delta, whereby the neutral of the star-connected winding is fully rated and brought to the outside.

The primary winding (HV) is normally connected in delta, the secondary winding (LV) in wye. The electrical offset of the windings in respect to each other is either 30, 150 or 330 degrees standard (Dy1, Dy5, Dy11). Other vector groups as well as single-phase transformers and autotransformers on request (Fig. 3). Power transformers Generator transformers and large power transformers are usually connected in Yd. For HV windings higher than 110 kV, the neutral has a reduced insulation level. For star/star-connected transformers and autotransformers normally a tertiary winding in delta, whose rating is a third of that of the transformer, has to be added. This stabilizes the phase-to phase voltages in the case of an unbalanced load and prevents the displacement of the neutral point. Single-phase transformers and autotransformers are used when the transportation possibilities are limited. They will be connected at site to three-phase transformer banks.

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Electrical Design

Insulation level Power-frequency withstand voltages and lightning-impulse withstand voltages are in accordance with IEC 76-3, Para. 5, Table II, as follows:

Highest voltage for equipment Um (r. m. s.)

[kV] ≤ 1.1

Rated lightningimpulse withstand voltage (peak)

Rated shortduration powerfrequency withstand voltage (r. m. s.)

List 1 [kV]

[kV] 3

List 2 [kV]

–

Conversion to 60 Hz – possibilities All ratings in the selection tables of this guide are based on 50 Hz operation. For 60 Hz operation, the following options apply: ■ 1. Rated power and impedance voltage are increased by 10%, all other parameters remain identical. ■ 2. Rated power increases by 20%, but no-load losses increase by 30% and noise level increases by 3 dB, all other parameters remain identical (this layout is not possible for cast-resin transformers). ■ 3. All technical data remain identical, price is reduced by 5%. ■ 4. Temperature rise is reduced by 10 K, load losses are reduced by 15%, all other parameters remain identical.

Transformer cell (indoor installation) The transformer cell must have the necessary electrical clearances when an open air connection is used. The ventilation system must be large enough to fulfill the recommendations for the maximum temperatures according to IEC. For larger power transformers either an oil/water cooling system has to be used or the oil/air cooler (radiator bank) has to be installed outside the transformer cell. In these cases a ventilation system has to be installed also to remove the heat caused by the convection of the transformer tank.

1

2

3

4

–

Overloading 3.6

10

20

40

7.2

20

40

60

12.0

28

60

75

17.5

38

75

95

24.0

50

95

125

36.0

70

145

170

52.0

95

250

72.5

140

325

123.0

185

450

230

550

275

650

325

750

360

850

395

950

Overloading of Siemens transformers is guided by the relevant IEC-354 ”Loading guide for oil-immersed transformers“ and the (similar) ANSI C57.92 ”Guide for loading mineral-oil-immersed power transformers“. Overloading of GEAFOL cast-resin transformers on request.

5

6

Routine and special tests

145.0

170.0

245.0

All transformers are subjected to the following routine tests in the factory: ■ Measurement of winding resistance ■ Measurement of voltage ratio and check of polarity or vector group ■ Measurement of impedance voltage ■ Measurement of load loss ■ Measurement of no-load loss and no-load current ■ Induced overvoltage withstand test ■ Seperate-source voltage withstand test ■ Partial discharge test (only GEAFOL cast-resin transformers). The following special tests are optional and must be specified in the inquiry: ■ Lightning-impulse voltage test (LI test), full-wave and chopped-wave (specify) ■ Partial discharge test ■ Heat-run test at natural or forced cooling (specify) ■ Noise level test ■ Short-circuit test. Test certificates are issued for all the above tests on request.

7

8

9

10

Higher test voltage withstand requirements must be stated in the inquiry and may result in a higher price.

Fig. 4: Insulation level

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Transformer Loss Evaluation

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The sharply increased cost of electrical energy has made it almost mandatory for buyers of electrical machinery to carefully evaluate the inherent losses of these items. In case of distribution and power transformers, which operate continuously and most frequently in loaded condition, this is especially important. As an example, the added cost of loss-optimized transformers can in most cases be recovered via savings in energy use in less than three years. Low-loss transformers use more and better materials for their construction and thus initially cost more. By stipulating loss evaluation figures in the transformer inquiry, the manufacturer receives the necessary incentive to provide a loss-optimized transformer rather than the lowcost model. Detailed loss evaluation methods for transformers have been developed and are described accurately in the literature, taking the project-specific evaluation factors of a given customer into account. The following simplified method for a quick evaluation of different quoted transformer losses is given, making the following assumptions: ■ The transformers are operated continuously ■ The transformers operate at partial load, but this partial load is constant ■ Additional cost and inflation factors are not considered ■ Demand charges are based on 100% load. The total cost of owning and operating a transformer for one year is thus defined as follows: ■ A. Capital cost Cc taking into account the purchase price Cp, the interest rate p, and the depreciation period n ■ B. Cost of no-load loss CP0, based on the no-load loss P0, and energy cost Ce ■ C. Cost of load loss Cpk, based on the copper loss Pk, the equivalent annual load factor a, and energy cost Ce ■ D. Demand charges Cd, based on the amount set by the utility, and the total kW of connected load. These individual costs are calculated as follows:

A. Capital cost

Cc = Cp

Cp · r

amount year

100

= purchase price

p · qn = depreciation factor qn – 1 p q= + 1 = interest factor 100

r=

p n

= interest rate in % p.a. = depreciation period in years

B. Cost of no-load loss

CP0 = Ce · 8760 h/year · P0 Ce

= energy charges

P0

= no-load loss [kW]

amount year

amount kWh

C. Cost of load loss

CPk = Ce · 8760 h/year · α2 · Pk

amount year

constant operation load rated load

α

=

Pk

= copper loss [kW]

D. Cost resulting from demands charges

CD = Cd (P0 + Pk) Cd

amount year

= demand charges

amount kW · year

Fig. 5

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Transformer Loss Evaluation

To demonstrate the usefulness of such calculations, the following arbitrary examples are shown, using factors that can be considered typical in Germany, and neglecting the effects of inflation on the rate assumed:

1

2 Example: 1600 kVA distribution transformer

Depreciation period Interest rate Energy charge

n = 20 years Depreciation factor p = 12% p. a. r = 13.39 Ce = 0.25 DM/kWh

Demand charge

Cd = 350

Equivalent annual load factor

α

A. Low-cost transformer

P0 = 2.6 kW Pk = 20 kW Cp = DM 25 000

3

DM kW · yr

4

= 0.8

B. Loss-optimized transformer

no-load loss load loss purchase price

Cc = 25000 · 13.39 100

P0 = 1.7 kW Pk = 17 kW Cp = DM 28 000

5

no-load loss load loss purchase price

6

Cc = 28000 · 13.39 100

= DM 3348/year

= DM 3 749/year

CP0 = 0.25 · 8760 · 2.6 = DM 5694/year

CP0 = 0.25 · 8760 · 1.7 = DM 3 723/year

CPk = 0.25 · 8760 · 0.64 · 20 = DM 28 032/year

CPk = 0.25 · 8760 · 0.64 · 17 = DM 23 827/year

CD = 350 · (2.6 + 20) = DM 7910/year

CD = 350 · (1.7 + 17) = DM 6 545/year

Total cost of owning and operating this transformer is thus:

Total cost of owning and operating this transformer is thus:

7

8

9 DM 44 984.–/year

DM 37 844.–/year

10 The energy saving of the optimized distribution transformer of DM 7140 per year pays for the increased purchase price in less than one year.

Fig. 6

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Mechanical Design

1

General mechanical design for oil-immersed transformers: ■ Iron core made of grain-oriented

2

■

3

■ ■

4

■ ■

■

5

6

7

8

9

10

electrical sheet steel insulated on both sides, core-type. Windings consisting of copper section wire or copper strip. The insulation has a high disruptive strength and is temperature-resistant, thus guaranteeing a long service life. Designed to withstand short circuit for at least 2 seconds (IEC). Oil-filled tank designed as tank with strong corrugated walls or as radiator tank. Transformer base with plain or flanged wheels (skid base available). Cooling/insulation liquid: Mineral oil according to VDE 0370/IEC 296. Silicone oil or synthetic liquids are available. Standard coating for indoor installation. Coatings for outdoor installation and for special applications (e.g. aggressive atmosphere) are available.

Tank design and oil preservation system Sealed-tank distribution transformers, TUMETIC® In ratings up to 2500 kVA and 170 kV LI this is the standard sealed-tank distribution transformer without conservator and gas cushion. The TUMETIC transformer is always completely filled with oil; oil expansion is taken up by the flexible corrugated steel tank (variable volume tank design), whereby the maximum operating pressure remains at only a fraction of the usual. These transformers are always shipped completely filled with oil and sealed for their lifetime. Bushings can be exchanged from the outside without draining the oil below the top of the active part. The hermetically sealed system prevents oxygen, nitrogen, or humidity from contact with the insulating oil. This improves the aging properties of the oil to the extent that no maintenance is required on these transformers for their lifetime. Generally the TUMETIC transformer is lower than the TUNORMA transformer. This design has been in successful service since 1973. A special TUMETIC-Protection device has been developed for this transformer.

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Distribution transformers with conservator, TUNORMA® This is the standard distribution transformer design in all ratings. The oil level in the tank and the top-mounted bushings is kept constant by a conservator vessel or expansion tank mounted at the highest point of the transformer. Oil-level changes due to thermal cycling affect the conservator only. The ambient air is prevented from direct contact with the insulating oil through oiltraps and dehydrating breathers. Tanks from 50 to approximately 4000 kVA are preferably of the corrugated steel design, whereby the sidewalls are formed on automatic machines into integral cooling pockets. Suitable spot welds and braces render the required mechanical stability. Tank bottom and cover are fabricated from rolled and welded steel plate. Conventional radiators are available. Power transformers Power transformers of all ratings are equipped with conservators. Both the open and closed system are available. With the closed system ”TUPROTECT®“ the oil does not come into contact with the surrounding air. The oil expansion is compensated with an air bag. (This design is also available for greater distribution transformers on request). The sealing bag consists of strong nylon braid with a special double lining of ozone and oil-resistant nitrile rubber. The interior of this bag is in contact with the ambient air through a dehydrating breather; the outside of this bag is in direct contact with the oil. All tanks, radiators and conservators (incl. conservator with airbag) are designed for vacuum filling of the oil. For transformers with on-load tap changers a seperate smaller conservator is necessary for the diverter switch compartment. This seperate conservator (without air bag) is normally an integrated part of the main conservator with its own magnetic oil level indicator. Power transformers up to 10 MVA are fitted with weld-on radiators and are shipped extensively assembled; shipping conditions permitting. Ratings above 10 MVA require detachable radiators with individual butterfly valves, and partial dismantling of components for shipment. All the usual fittings and accessories for oil treatment, shipping and installation of these transformers are provided as standard. For monitoring and protective devices, see the listing on page 5/11.

Fig. 7: Cross section of a TUMETIC three-phase distribution transformer

Fig. 8: 630 kVA, three-phase, TUNORMA 20 kV ± 2.5 %/0.4 kV distribution transformer

Fig. 9: Practically maintenancefree: transformer with the TUPROTECT air-sealing system built into the conservator

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Connection Systems

Distribution transformers 1

All Siemens transformers have top-mounted HV and LV bushings according to DIN in their standard version. Besides the open bushing arrangement for direct connection of bare or insulated wires, three basic insulated termination systems are available:

2

Fully enclosed terminal box for cables (Fig. 11) Available for either HV or LV side, or for both. Horizontally split design in degree of protection IP 44 or IP 54. (Totally enclosed and fully protected against contact with live parts, plus protection against drip, splash, or spray water.) Cable installation through split cable glands and removable plates facing diagonally downwards. Optional conduit hubs. Suitable for single-core or three-phase cables with solid dielectric insulation, with or without stress cones. Multiple cables per phase are terminated on auxiliary bus structures attached to the bushings. Removal of transformer by simply bending back the cables.

3

4 Fig. 11: Fully enclosed cable connection box

5

6

Insulated plug connectors (Fig. 12) For substation installations, suitable HV can be attached via insulated elbow connectors in LI ratings up to 170 kV.

7

Flange connection (Fig. 13) Air-insulated bus ducts, insulated busbars, or throat-connected switchgear cubicles are connected via standardized flanges on steel terminal enclosures. These can accommodate either HV, LV, or both bushings. Fiberglass-reinforced epoxy partitions are available between HV and LV bushings if flange/flange arrangements are chosen. The following combinations of connection systems are possible besides open bushing arrangements:

HV

LV

Cable box

Cable box

Cable box

Flange/throat

Flange

Cable box

Flange

Flange/throat

Elbow connector

Cable box

Elbow connector

Flange/throat

Fig. 10: Combination of connection systems

8 Fig. 12: Grounded metal-elbow plug connectors

9

10

Fig 13: Flange connection for switchgear and bus ducts

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Connection Systems

Power transformers 1

2

3

4

5

The most frequently used type of connection for transformers is the outdoor bushing. Depending on voltage, current, system conditions and transport requirements, the transformers will be supplied with bushings arranged vertically, horizontally or inclined. Up to about 110 kV it is usual to use oil-filled bushings according to DIN; condenser bushings are normally used for higher voltages. Limited space or other design considerations often make it necessary to connect cables directly to the transformer. For voltages up to 30 kV air-filled cable boxes are used. For higher voltages the boxes are oil-filled. They may be attached to the tank cover or to its walls (Fig. 14). The space-saving design of SF6-insulated switchgear is one of its major advantages. The substation transformer is connected directly to the SF6 switchgear. This eliminates the need for an intermediate link (cable, overhead line) between transformer and system (Fig. 15).

6 Fig. 14: Transformers with oil-filled HV cable boxes

7

8

9

10

Fig. 15: Direct SF6-connection of the transformer to the switchgear

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Accessories and Protective Devices Accessories not listed completely. Deviations are possible.

Double-float Buchholz relay (Fig. 16) For sudden pressure rise and gas detection in oil-immersed transformer tanks with conservator. Installed in the connecting pipe between tank and conservator and responding to internal arcing faults and slow decomposition of insulating materials. Additionally, backup function of oil alarm. The relay is actuated either by pressure waves or gas accumulation, or by loss of oil below the relay level. Seperate contacts are installed for alarm and tripping. In case of a gas accumulation alarm, gas samples can be drawn directly at the relay with a small chemical testing kit. Discoloring of two liquids indicates either arcing byproducts or insulation decomposition products in the oil. No change in color indicates an air bubble.

1

2

3

4

Fig. 16: Double-float Buchholz relay

Dial-type contact thermometer (Fig. 17) Indicates actual top-oil temperature via capillary tube. Sensor mounted in well in tank cover. Up to four separately adjustable alarm contacts and one maximum pointer are available. Installed to be readable from the ground. With the addition of a CT-fed thermal replica circuit, the simulated hot-spot winding temperature of one or more phases can be indicated on identical thermometers. These instruments can also be used to control forced cooling equipment.

5

6

7

8

Fig. 17: Dial-type contact thermometer

Magnetic oil-level indicator (Fig. 18) The float position inside of the conservator is transmitted magnetically through the tank wall to the indicator to preserve the tank sealing standard device without contacts; devices supplied with limit (position) switches for high- and low-level alarm are available. Readable from the ground.

9

10

Fig. 18: Magnetic oil-level indicator

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Accessories and Protective Devices

Protective device (Fig. 19) for hermetically sealed transformers (TUMETIC)

1

For use on hermetically sealed TUMETIC distribution transformers. Gives alarm upon loss of oil and gas accumulation. Mounted directly at the (permanently sealed) filler pipe of these transformers.

2 Pressure relief device (Fig. 20) Relieves abnormally high internal pressure shock waves. Easily visible operation pointer and alarm contact. Reseals positively after operation and continues to function without operator action.

3

Dehydrating breather (Fig. 21, 22) A dehydrating breather removes most of the moisture from the air which is drawn into the conservator as the transformer cools down. The absence of moisture in the air largely eliminates any reduction in the breakdown strength of the insulation and prevents any buildup of condensation in the conservator. Therefore, the dehydrating breather contributes to safe and reliable operation of the transformer.

4

5

6

Fig. 19: Protective device for hermetically sealed transformers (TUMETIC)

Fig. 20: Pressure relief device with alarm contact and automatic resetting

Bushing current transformer Up to three ring-type current transformers per phase can be installed in power transformers on the upper and lower voltage side. These multiratio CTs are supplied in all common accuracy and burden ratings for metering and protection. Their secondary terminals are brought out to shortcircuiting-type terminal blocks in watertight terminal boxes.

7

8

Additional accessories Besides the standard accessories and protective devices there are additional items available, especially for large power transformers. They will be offered and installed on request. Examples are: ■ Fiber-optic temperature measurements ■ Permanent gas-in-oil analysis ■ Permanent water-content measurement ■ Sudden pressure rise relay, etc.

9

10

Fig. 21: Dehydrating breather A DIN 42 567 up to 5 MVA

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Fig. 22: Dehydrating breather L DIN 42 562 over 5 MVA

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Technical Data Distribution Transformers TUNORMA and TUMETIC

Oil-immersed TUMETIC and TUNORMA three-phase distribution transformers

12 11 10

3

1

8 2N 2U 2V 2W

■ ■ ■ ■ ■ ■

■

■

■ ■ ■

Standard: DIN 42500 Rated power: 50–2500 kVA Rated frequency: 50 Hz HV rating: up to 36 kV Taps on ± 2.5 % or ± 2 x 2.5 % HV side: LV rating: 400–720 V (special designs for up to 12 kV can be built) Connection: HV winding: delta LV winding: star (up to 100 kVA: zigzag) Impedance 4 % (only up to HV voltage at rated rating 24 kV and current: ≤ 630 kVA) or 6 % (with rated power ≥ 630 kVA or with HV rating > 24 kV) Cooling: ONAN Protection class: IP00 Final coating: RAL 7033 (other colours are available)

H1

1U 2U 1W

B1

2

7 9 E 2 3 6 7 8

6

8

2

Oil drain plug Thermometer pocket Adjustment for off-load tap changer Rating plate (relocatable) Grounding terminals

E

A1

9 10 11 12

Towing eye, 30 mm dia. Lashing lug Filler pipe Mounting facility for protective device

3

4

Fig. 24: TUMETIC distribution transformer (sealed tank)

5

4

1

5 10

3 8 2N 2U 2V 2W

H1

1U 2U 1W

B1

6

7

Um

LI

AC

[kV]

[kV]

[kV]

1.1

–

3

12

75

28

24

125

50

36

170

70

LI Lightning-impulse test voltage AC Power-frequency test voltage Fig. 23: Insulation level (IP00)

9 2 E 1 2 3 4 5

A1

E

Oil level indicator Oil drain plug Thermometer pocket Buchholz relay (optional extra) Dehydrating breather (optional extra)

6 7 8 9 10

13

7

Adjustment for off-load tap changer Rating plate (relocatable) Grounding terminals Towing eye, 30 mm dia. Lashing lug

Notes: Tank with strong corrugated walls shown in illustration is the preferred design. With HV ratings up to 24 kV and rated power up to 250 kVA (and with HV ratings > 24-36 kV and rated power up to 800 kVA), the conservator is fitted on the long side just above the LV bushings.

8

Fig. 25: TUNORMA distribution transformer (with conservator)

Losses The standard HD 428.1.S1 (= DIN 42500 Part 1) applies to three-phase oil-immersed distribution transformers 50 Hz, from 50 kVA to 2500 kVA, Um to 24 kV. For load losses (Pk), three different listings (A, B and C) were specified. There were also three listings (A’, B’ and C’) for no-load losses (P0) and corresponding sound levels. Due to the different requirements, pairs of values were proposed which, in the national standard, permit one or several combinations of losses. DIN 42500 specifies the combinations A-C’, C-C’ and B-A’ as being most suitable.

The combinations B-A’ (normal losses) and A-C’ (reduced losses) are approximately in line with previous standards. In addition there is the C-C’ combination. Transformers of this kind with additionally reduced losses are especially economical with energy (maximum efficiency > 99%). The higher costs of these transformers are counteracted by the energy savings which they make. Standard HD 428.3.S1 (= DIN 42500-3) specifies the losses for oil distribution transformers up to Um = 36 kV. For load losses the listings D and E, for no-load losses the listings D’ and E’ were specified. In order to find the most efficient transformer, please see part ”Transformer loss evaluation“.

5/13

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22.09.1999, 16:23 Uhr

9

10

Technical Data Distribution Transformers TUNORMA and TUMETIC

TUMETIC

TUNORMA

TUMETIC

TUNORMA

TUMETIC

TUNORMA

1350

42

55

340 350

860

980 660

660 1210 1085 520

..4744-3RB

A-C'

125

1100

34

47

400 430

825 1045 660

660 1210 1085 520

4

..4744-3TB

C-C'

125

875

34

47

420 440

835

985 660

660 1220 1095 520

4

..4767-3LB

B-A'

190

1350

42

55

370 380

760

860 660

660 1315 1235 520

4

..4767-3RB

A-C'

125

1100

34

47

430 460

860

860 660

660 1300 1220 520

4

..4767-3TB

C-C'

125

875

33

47

480 510

880 1100 685

660 1385 1265 520

36

6

..4780-3CB

E-D´

230

1450

x

52

500

12

4

..5044-3LB

B-A'

320

2150

45

59

500 500

4

..5044-3RB

A-C'

210

1750

35

49

570 570

980

980 660

660 1315 1145 520

4

..5044-3TB

C-C'

210

1475

35

49

600 620

1030

930 660

660 1320 1150 520

4

..5067-3LB

B-A'

320

2150

45

59

520 530

1020 1140 685

660 1360 1245 520

4

..5067-3RB

A-C'

210

1750

35

49

600 610

1030 1030 690

660 1400 1280 520

4

..5067-3TB

C-C'

210

1475

35

49

640 680

960 1060 695

660 1425 1305 520

36

6

..5080-3CB

E-D´

380

2350

x

56

660

12

4

..5244 -3LA

B-A'

460

3100

47

62

620 610

1140 1140 710

710 1350 1185 520

4

..5244-3RA

A-C'

300

2350

37

52

700 690

1130 1010 660

660 1390 1220 520

4

..5244-3TA

C-C'

300

2000

38

52

760 780

985 1085 660

660 1380 1215 520

4

..5267-3LA

B-A'

460

3100

47

62

660 640

1150 1150 695

660 1440 1320 520

4

..5267-3RA

A-C'

300

2350

37

52

730 730

1030

930 695

660 1540 1420 520

4

..5267-3TA

C-C'

300

2000

37

52

800 820

1120 1120 710

660 1475 1355 520

36

6

..5280-3CA

E-D´

520

3350

x

59

900

1120

12

4

..5344-3LA

B-A'

550

3600

48

63

720 710

1190 1190 680

680 1450 1285 520

4

..5344-3RA

A-C'

360

2760

38

53

840 830

1070 1120 660

660 1470 1300 520

4

..5344-3TA

C-C'

360

2350

38

53

900 920

1130 1130 660

680 1450 1285 520

4

..5367-3LA

B-A'

550

3600

48

63

800 780

1290 1290 820

800 1595 1425 520

4

..5367-3RA

A-C'

360

2760

38

53

890 910

1110 1230 755

680 1630 1460 520

4

..5367-3TA

C-C'

360

2350

38

53

950 980

1080 1180 705

690 1595 1430 520

6

..5380-3CA

E-D´

600

3800

x

61

..4744-3LB

4

4

24

6

24

10

TUMETIC

190

4

(200)

Dist. between wheel centers

B-A'

12

9

Height H1

Width B1

[kg]

50

8

Length A1

LWA [dB]

4JB… 4HB…

160

Dimensions

Total weight

LPA [dB]

U2 [%]

24

7

Sound power level

Pk 75* [W]

Um [kV]

100

CENELEC

Sound press. level 1m tolerance + 3 dB

P0 [W]

Sn [kVA]

3

5

Combi- No-load Load nation of losses losses losses acc.

Type

TUNORMA

Max. Imperated dance volt. voltage HV side

TUMETIC

2

Rated power

TUNORMA

1

24

36

Dimensions and weights are approximate values. Rated power figures in parentheses are not standardized.

1000

[mm]

x

x

x

x

1000

[mm]

x 710

1090 1020 660

1050

1250

x 780

x 800

x 800

[mm]

x 1530

E [mm]

x 520

660 1275 1110 520

x 1600

x 1700

x 1700

x 520

x 520

x 520

x: on request

* In case of short-circuits at 75 °C

Fig. 26: Selection table: oil-immersed distribution transformers 50 to 2500 kVA

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14

22.09.1999, 16:23 Uhr

Technical Data Distribution Transformers TUNORMA and TUMETIC

P0 [W]

Height H1

Dist. between wheel centers

TUMETIC

TUNORMA

TUMETIC

LWA [dB]

Width B1 TUNORMA

LPA [dB]

Length A1 TUMETIC

Pk 75* [W]

CENELEC

Dimensions

Total weight

TUNORMA

Sound power level

TUNORMA

Sound press. level 1m tolerance + 3 dB

TUMETIC

Combi- No-load Load nation of losses losses losses acc.

Type

TUMETIC

Max. Imperated dance volt. voltage HV side

TUNORMA

Rated power

Sn [kVA]

Um [kV]

U2 [%]

250

12

4

..5444-3LA B-A'

650

4200

50

65

830 820 1300 1300

810 810 1450 1285 520

4

..5444-3RA A-C'

425

3250

40

55

940 920 1260 1260

670 820 1480 1415 520

4

..5444-3TA C-C'

425

2750

40

55

1050 1070 1220 1220

690 700 1530 1310 520

4

..5467-3LA B-A'

650

4200

49

65

920 900 1340 1340

800 760 1620 1450 520

4

..5467-3RA A-C'

425

3250

39

55

1010 1010 1140 1190

760 680 1675 1510 520

4

..5467-3TA C-C'

425

2750

40

55

1120 1140 1220 1340

715 710 1640 1475 520

36

6

..5480-3CA E-E´

650

4250

x

62

1100

800

12

4

..5544-3LA B-A'

780

5000

50

66

980 960 1440 1330

820 820 1655 1385 670

4

..5544-3RA A-C'

510

3850

40

56

1120 1100 1400 1250

820 820 1690 1415 670

4

..5544-3TA C-C'

510

3250

40

56

1240 1260 1380 1260

820 820 1665 1390 670

4

..5567-3LA B-A'

780

5000

50

66

1050 1030 1450 1350

840 840 1655 1510 670

4

..5567-3RA A-C'

510

3850

40

56

1170 1150 1410 1270

820 820 1755 1610 670

4

..5567-3TA C-C'

510

3250

40

56

1250 1280 1395 1290

820 820 1675 1540 670

36

6

..5580-3CA E-E´

760

5400

x

64

1220

960

12

4

..5644-3LA B-A'

930

6000

52

68

1180 1160 1470 1390

930 930 1700 1425 670

4

..5644-3RA A-C'

610

4600

42

58

1320 1310 1400 1360

820 820 1700 1430 670

4

..5644-3TA C-C'

610

3850

42

58

1470 1470 1410 1390

820 820 1695 1420 670

4

..5667-3LA B-A'

930

6000

52

68

1240 1220 1570 1570

940 940 1655 1510 670

4

..5667-3RA A-C'

610

4600

42

58

1370 1350 1475 1400

820 820 1760 1615 670

4

..5667-3TA C-C'

610

3850

42

58

1490 1520 1440 1400

820 820 1765 1540 670

36

6

..5580-3CA E-E´

930

6200

x

65

1480

990

12

4

..5744-3LA B-A'

1100

7100

53

69

1410 1380 1500 1430

840 840 1710 1440 670

4

..5744-3RA A-C'

720

5450

42

59

1650 1620 1560 1550

890 890 1745 1470 670

4

..5744-3TA C-C'

720

4550

43

59

1700 1710 1500 1470

820 820 1745 1470 670

4

..5767-3LA B-A'

1100

7100

53

69

1460 1440 1470 1530

835 850 1755 1610 670

4

..5767-3RA A-C'

720

5450

42

59

1650 1620 1495 1420

835 820 1815 1665 670

4

..5767-3TA C-C'

720

4550

43

59

1860 1910 1535 1500

820 820 1860 1645 670

6

..5780-3CA E-E´

1050

7800

x

66

1680

24

(315)

24

400

24

(500)

24

36

4JB… 4HB…

Dimensions and weights are approximate values. Rated power figures in parentheses are not standardized.

[kg]

[mm]

x 1350

x 1420

x 1470

x 1510

[mm]

x

x

x

x 1030

[mm]

x 1680

x 1700

x 1830

x 1900

2

E [mm]

3

4

x 520

5

6

x 670

7

8

x 670

9

10

x 670

x: on request

* In case of short-circuits at 75 °C

Fig. 27: Selection table: oil-immersed distribution transformers 50 to 2500 kVA

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Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Ohne Namen-1

15

22.09.1999, 16:23 Uhr

1

Technical Data Distribution Transformers TUNORMA and TUMETIC

Um [kV]

U2 [%]

630

12

4

..5844-3LA B-A'

4

Dist. between wheel centers

TUMETIC

TUNORMA

TUMETIC

TUNORMA

TUMETIC

TUNORMA

TUMETIC

Height H1

Width B1

E [mm]

LWA [dB]

1300

8400

53

70

1660 1660 1680 1480

880 880 1755 1585 670

..5844-3RA A-C'

860

6500

43

60

1850 1810 1495 1420

835 820 1785 1510 670

4

..5844-3TA C-C'

860

5400

43

60

2000 1990 1535 1380

820 820 1860 1520 670

6

..5844-3PA B-A'

1200

8700

53

70

1750 1760 1720 1560

890 890 1920 1685 670

6

..5844-3SA A-C'

800

6750

43

60

1950 1920 1665 1600

870 870 1740 1400 670

6

..5844-3UA C-C'

800

5600

43

60

2160 2130 1670 1560

830 830 1840 1500 670

4

..5867-3LA B-A'

1300

8400

53

70

1690 1650 1665 1640

860 860 1810 1595 670

4

..5867-3RA A-C'

860

6500

43

60

1940 1920 1685 1680

870 870 1910 1695 670

4

..5867-3TA C-C'

860

5400

43

60

2100 2130 1600 1490

820 820 1940 1725 670

6

..5867-3PA B-A'

1200

8700

53

70

1730 1720 1780 1580

880 880 1760 1610 670

6

..5867-3SA A-C'

800

6750

43

60

1970 1960 1645 1640

830 830 1810 1595 670

6

..5867-3UA C-C'

800

5600

43

60

2240 2210 1740 1670

880 880 1840 1625 670

36

6

..5880-3CA E-E´

1300

8800

x

67

1950

12

6

..5944-3PA B-A'

1450

10700

55

72

1990 1960 1780 1540 1000 1000 1905 1660 670

6

..5944-3SA A-C'

950

8500

45

62

2210 2290 1720 1830

900 960 1935 1630 670

6

..5944-3UA C-C'

950

7400

44

62

2520 2490 1760 1710

920 920 1975 1730 670

6

..5967-3PA B-A'

1450

10700

55

72

2000 1950 1720 1710 1000 1000 1885 1670 670

6

..5967-3SA A-C'

950

8500

45

62

2390 2340 1760 1710

960 960 1945 1730 670

6

..5967-3UA C-C'

950

7400

44

62

2590 2550 1770 1700

930 930 1985 1780 670

36

6

..5980-3CA E-E´

1520

11000

x

68

2400

12

6

..6044-3PA B-A'

1700

13000

55

73

2450 2640 1790 1630 1000 1000 2095 2070 820

6

..6044-3SA A-C'

1100

10500

45

63

2660 2610 1830 1830 1040 1040 2025 1770 820

6

..6044-3UA C-C'

1100

9500

45

63

2800 2750 1830 1830 1040 1040 2105 1840 820

6

..6067-3PA B-A'

1700

13000

55

73

2530 2720 1830 1670 1090 1010 2095 2120 820

6

..6067-3SA A-C'

1100

10500

45

63

2750 2690 1790 1740 1050 1050 2055 1840 820

6

..6067-3UA C-C'

1100

9500

45

63

2830 2810 1725 1770

6

..6080 -3CA E-E´

1700

13000

x

68

2850

5

6

7 24

8

24

10

Length A1

LPA [dB]

24

1000

Dimensions

Total weight

Pk 75* [W]

4

(800)

P0 [W]

Sound Sound press. power level level 1m tolerance + 3 dB

TUNORMA

CENELEC

Sn [kVA]

3

9

Combi- No-load Load nation of losses losses losses acc.

Type

TUMETIC

2

Max. Imperated dance volt. voltage HV side

TUNORMA

1

Rated power

36

4JB… 4HB…

Dimensions and weights are approximate values. Rated power figures in parentheses are not standardized.

[kg]

[mm]

x 1740

x 1800

x 2120

[mm]

x 1080

x 1100

[mm]

x 1940

x 2030

x 670

x 670

990 990 2065 1850 820

x 1160

x 2220

x 820

x: on request

* In case of short-circuits at 75 °C

Fig. 28: Selection table: oil-immersed distribution transformers 50 to 2500 kVA

5/16

Ohne Namen-1

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

16

22.09.1999, 16:23 Uhr

Technical Data Distribution Transformers TUNORMA and TUMETIC

Height H1

Dist. between wheel centers

TUMETIC

TUNORMA

TUMETIC

TUNORMA

Width B1

TUMETIC

TUNORMA

TUMETIC

TUMETIC

Length A1

LPA [dB]

LWA [dB]

..6144-3PA B-A'

2100

16000

56

74

2900 3080 1930 1850 1260 1100 2110 2070 820

6

..6144-3SA A-C'

1300

13200

46

64

3100 3040 1810 1780

6

..6144-3UA C-C'

1300

11400

46

64

3340 3040 1755 1720 1015 1000 2235 1970 820

6

..6167-3PA B-A'

2100

16000

56

74

2950 3200 2020 1780 1260 1100 2110 2220 820

6

..6167-3SA A-C'

1300

13200

46

64

3190 3120 1840 1810 1060 1060 2115 1900 820

6

..6167-3UA C-C'

1300

11400

46

64

3390 3330 1810 1780 1015

36

6

..6180-3CA E-E´

2150

16400

x

70

3360

12

6

..6244-3PA B-A'

2600

20000

57

76

3450 3590 1970 1870 1220 1140 2315 2095 820

6

..6244-3SA A-C'

1700

17000

47

66

3640 3590 2030 1760 1080 1090 2315 2010 820

6

..6244-3UA C-C'

1700

14000

47

66

3930 3880 2020 1900 1110 1100 2395 2070 820

6

..6267-3PA B-A'

2600

20000

57

76

3470 3690 2070 1830 1280 1120 2335 2320 820

6

..6267-3SA A-C'

1700

17000

47

66

3670 3850 2030 2000 1230 1070 2265 2120 820

6

..6267-3UA C-C'

1700

14000

47

66

4010 3950 2000 1850 1030 1030 2305 2010 820

36

6

..6280-3CA E-E´

2600

19200

x

71

3930

12

6

..6344-3PA B-A'

2900

25300

58

78

4390 4450 2100 1890 1330 1330 2555 2540 1070

6

..6344-3SA A-C'

2050

21200

49

68

4270 4430 2080 1840 1330 1330 2455 2250 1070

6

..6344-3UA C-C'

2050

17500

49

68

4730 4710 2020 1730 1330 1330 2495 2170 1070

6

..6367-3PA B-A'

2900

25300

58

78

4480 4500 2020 1860 1330 1330 2655 2660 1070

6

..6367-3SA A-C'

2050

21200

49

68

4290 4490 2190 2030 1330 1330 2425 2280 1070

6

..6367-3UA C-C'

2050

17500

49

68

4910 4840 2110 1980 1330 1330 2475 2180 1070

36

6

..6380-3CA E-E´

3200

22000

x

75

5100

12

6

..6444-3PA B-A'

3500

29000

61

81

5200 5090 2115 2030 1345 1330 2685 2550 1070

6

..6444-3SA A-C'

2500

26500

51

71

5150 5110 2195 1950 1345 1330 2535 2450 1070

6

..6444-3UA C-C'

2500

22000

51

71

5790 5660 2190 2190 1330 1330 2565 2240 1070

6

..6467-3PA B-A'

3500

29000

61

81

5420 5220 2115 2030 1335 1330 2785 2675 1070

6

..6467-3SA A-C'

2500

26500

51

71

5260 5220 2195 2030 1335 1335 2585 2580 1070

6

..6467-3UA C-C'

2500

22000

51

71

5640 5470 2160 2080 1330 1330 2605 2305 1070

6

..6480-3CA E-E´

3800

29400

x

76

5900

U2 [%]

(1250)

12

6

24

24

24

2500

Dimensions

Total weight

Pk 75* [W]

Um [kV]

(2000)

CENELEC

Sound Sound press. power level level 1m tolerance + 3 dB

P0 [W]

Sn [kVA]

1600

Combi- No-load Load nation of losses losses losses acc.

Type

TUNORMA

Max. Imperated dance volt. voltage HV side

TUNORMA

Rated power

24

36

4JB… 4HB…

Dimensions and weights are approximate values. Rated power figures in parentheses are not standardized.

[kg]

[mm]

x 2150

x 2170

x 2260

x 2320

[mm]

990

x 1250

x 1340

x 1380

x 1390

[mm]

2

E [mm]

990 2145 1880 820

3

4

990 2245 2030 820 x 2350

x 2480

x 2560

x 2790

x 820

5

6

x 820

7

8

x 1070

9

10

x 1070

x: on request

* In case of short-circuits at 75 °C

Fig. 29: Selection table: oil-immersed distribution transformers 50 to 2500 kVA

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Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Ohne Namen-1

17

22.09.1999, 16:23 Uhr

1

Power Transformers – General

1

Oil-immersed three-phase power transformers with offand on-load tap changers

Rated power

HV range

Type of tap changer

Figure/ page

[MVA]

[kV]

3.15 to 10

25 to 123

off-load

Fig. 31, page 5/19

3.15 to 10

25 to 123

on-load

Fig. 33, page 5/20

10/16 to 20/31.5

up to 36

off-load

Fig. 35, page 5/21

10/16 to 20/31.5

up to 36

on-load

Fig. 38, page 5/22

10/16 to 63/100

72.5 to 145

on-load

Fig. 41, page 5/23

Cooling methods

2

3

4

5

6

Transformers up to 10 MVA are designed for ONAN cooling. By adding fans to these transformers, the rating can be increased by 25%. However, in general it is more economical to select higher ONAN ratings rather than to add fans. Transformers larger than 10 MVA are designed with ONAN/ONAF cooling. Explanation of cooling methods: ■ ONAN: Oil-natural, air-natural cooling ■ ONAF: Oil-natural, air-forced cooling (in one or two steps) The arrangement with the attached radiators, as shown in the illustrations, is the preferred design. However, other arrangements of the cooling equipment are also possible. Depending on transportation possibilities the bushings, radiators and expansion tank have be removed. If necessary, the oil has to be drained and shipped separately.

Note: Off-load tap changers are designed to be operated de-energized only.

Fig. 30: Types of power transformers

7

8

9

10

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Ohne Namen-1

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

18

22.09.1999, 16:23 Uhr

Power Transformers – Selection Tables Technical Data, Dimensions and Weights

Oil-immersed three-phase power transformers with off-load tap changer 3 150–10 000 kVA, HV rating: up to 123 kV

1

2 ■ Taps on

HV side:

H

± 2 x 2.5 %

■ Rated frequency: 50 Hz ■ Impedance 6-10 %

3

voltage: ■ Connection:

HV winding: stardelta connection alternatively available up to 24 kV LV winding: star or delta

E

L

E W

4

Fig. 31

Rated power

HV rating

LV rating

No-load loss

Load loss Total at 75 °C weight

Oil weight

Dimensions L/W/H

E

[kVA] ONAN

[kV]

[kV]

[kW]

[kW]

[kg]

[mm]

[mm]

3150

6.1–36

3–24

4.6

28

7200

1600

2800/1850/2870

1070

4000

7.8–36

3–24

5.5

33

8400

1900

3200/2170/2940

1070

50–72.5

3–24

6.8

35

10800

3100

3100/2300/3630

1070

9.5–36

4–24

6.5

38

9800

2300

2550/2510/3020

1070

50–72.5

4–24

8.0

41

12200

3300

3150/2490/3730

1070

90–123

5–36

9.8

46

17500

6300

4560/2200/4540

1505 1505

5000

6300

8000

10000

[kg]

12.2–36

5–24

7.7

45

11700

2500

2550/2840/3200

50–72.5

5–24

9.3

48

13600

3700

3200/2690/3080

1505

90–123

5–36

11.0

53

18900

6600

4780/2600/4540

1505

12.2–36

5–24

9.4

54

14000

3300

2580/2770/3530

1505

50–72.5

5–24

11.0

56

15900

4200

3250/2850/4000

1505

90–123

5–36

12.5

62

21500

7300

4880/2630/4590

1505

15.2–36

6–24

11.0

63

16600

3900

2670/2900/3720

1505

50–72.5

6–24

12.5

65

18200

4700

4060/2750/4170

1505

90–123

5–36

14.0

72

25000

8600

4970/2900/4810

1505

5

6

7

8

9

10

Fig. 32

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Power Transformers – Selection Tables Technical Data, Dimensions and Weights

1

Oil-immersed three-phase power transformers with on-load tap changer 3 150–10 000 kVA, HV rating: up to 123 kV H

2 ± 16 % in ± 8 steps HV side: of 2 % ■ Rated frequency: 50 Hz ■ Impedance 6–10 % voltage: ■ Connection: HV winding: star LV winding: star or delta ■ Taps on

3

4 HV rating

LV rating

No-load loss

Load loss at 75 °C

Total weight

Oil weight

Dimensions L/W/H

E

[kVA] ONAN

[kV]

[kV]

kW

[kW]

[kg]

[kg]

[mm]

[mm]

3150

10.9–36

3–24

4.8

29

9100

2300

3400/2300/2900

1070

4000

9.2–36

3–24

5.8

35

10300

2600

3500/2700/3000

1070

50–72.5

4–24

7.1

37

13700

4100

4150/2350/3600

1070

11.5–36

4–24

6.8

40

12300

3100

3600/2400/3200

1070

50–72.5

5–24

8.4

43

15200

4500

4200/2700/3700

1070

90–123

5–36

9.8

49

21800

8000

5300/2700/4650

1505

14.4–36

5–24

8.1

47

14000

3600

3700/2700/3300

1505

50–72.5

5–24

9.8

50

17000

5000

4300/2900/3850

1505

90–123

5–36

11.5

56

23000

8500

5600/2900/4650

1505

18.3–36

5–24

9.9

57

17000

4500

3850/2500/3500

1505

50–72.5

5–24

11.5

59

19700

6000

4600/2800/4050

1505

90–123

5–36

13.1

65

25500

9000

5650/2950/4650

1505

22.9–36

6–24

11.5

66

20000

5200

4400/2600/3650

1505

50–72.5

6–24

13.1

68

22500

6500

5200/2850/4100

1505

90–123

5–36

14.7

76

29500

10250

5750/2950/4700

1505

5000

9

10

L

Rated power

7

8

E W

Fig. 33

5

6

E

6300

8000

10000

Fig. 34

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Power Transformers – Selection Tables Technical Data, Dimensions and Weights

Oil-immersed three-phase power transformers with off-load tap changer 10/16 to 20/31.5 MVA HV rating: up to 36 kV

1

H

2

Hs ■ Rated frequency: 50 Hz, tapping range ■ Connection of

± 2 x 2.5 % star

HV winding: ■ Connection of

star or delta LV winding: ■ Cooling method: ONAN/ONAF ■ LV range: 6 kV to 36 kV

3

L Ls

E W Ws

E

Fig. 35

4

Rated power at ONAF ONAN

No-load loss

Load loss at ONAN ONAF

Impedance voltage of ONAN ONAF

[MVA]

[MVA]

[kW]

[kW]

[kW]

[%]

[%]

10

16

12

31

80

6.3

10

12.5

20

14

37

95

6.3

10

16

25

16

45

110

6.4

10

20

31.5

19

52

130

6.4

10

5

6

7

Fig. 36

Rated power at ONAN ONAF [MVA]

[MVA]

10

16

12.5

Dimensions L x W x

H

Total weight

Oil weight

Shipping dimensions Ls x Ws

x Hs

Shipping weight incl. oil

[kg]

[kg]

[mm]

[kg]

3700 2350 3900

22

4200

3600 1550 2650

22000

20

3800 2350 4000

25

4500

3700 1600 2800

23000

16

25

3900 2400 4100

30

5000

3800 1600 2800

27000

20

31.5

4200 2450 4600

35

5700

3900 1650 3000

31500

[mm]

Fig. 37

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8

9

10

Power Transformers – Selection Tables Technical Data, Dimensions and Weights

1

Oil-immersed three-phase power transformer with on-load tap changer 10/16 to 20/31.5 MVA, HV rating: up to 36 kV

H

2

Hs

■ Rated frequency: 50 Hz, tapping range ■ Connection of

3

± 16 % in ± 9 steps star

HV winding: ■ Connection of

star or delta LV winding: ■ Cooling method: ONAN/ONAF ■ LV range: 6 kV to 36 kV

Ls

Ws W

L

Fig. 38

4

Rated power at ONAN ONAF

No-load loss

Load loss at ONAN ONAF

Impedance voltage of ONAN ONAF

[MVA]

[MVA]

[kW]

[kW]

[kW]

[%]

[%]

10

16

12

31

80

6.3

10

12.5

20

14

37

95

6.3

10

16

25

16

45

111

6.4

10

20

31.5

19

52

130

6.4

10

5

6

7

Fig. 39

Rated power at ONAN ONAF

8

9

10

[MVA]

[MVA]

10

16

12.5

Dimensions L x W x

H

Total weight [kg]

Oil weight

Shipping dimensions Ls x Ws

x Hs

Shipping weight incl. oil

[kg]

[mm]

[kg]

4800 2450 3900 27000

6200

4400 1550 2600

24000

20

4900 2500 4000 30000

6700

4500 1600 2650

27000

16

25

5050 2500 4100 34000

7000

4650 1650 2650

31000

20

31.5

5300 2550 4600 41 000

9000

5000 1700 3000

37000

[mm]

Fig. 40

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Power Transformers – Selection Tables Technical Data, Dimensions and Weights

Oil-immersed three-phase power transformers with on-load tap changer 10/16 to 63/100 MVA, HV rating: from 72.5 to 145 kV ■ Rated frequency: 50 Hz, tapping range ■ Connection of

± 16 % in ± 9 steps star

HV winding: ■ Connection star or delta of LV winding: ■ Cooling method: ONAN/ONAF

Rated power at ONAN ONAF

No-load loss

Load loss at ONAN

ONAF

Impedance voltage of ONAN ONAF

[MVA] [MVA]

[kW]

[kW]

[kW]

[%]

[%]

10

16

13

42

108

9.6

15.4

12.5

20

15

45

115

9.4

15.0

16

25

17

51

125

9.6

15.0

20

31.5

20

56

140

9.6

15.1

25

40

24

63

160

9.5

15.2

31.5

50

28

71

180

9.5

15.0

40

63

35

86

214

9.8

15.5

50

80

41

91

232

10.0

16.0

63

100

49

113

285

10.5

16.7

1

2

3

4

5

Fig. 41

Rated power at Dimensions ONAN ONAF L x W x [MVA]

[MVA]

H

[mm]

Total weight

Oil weight

Shipping dimensions Ls x Ws x Hs

Shipping weight incl. oil

[kg]

[kg]

[mm]

[kg]

10

16

6600 2650 4700

39000

12000

5200 1900

3000

35000

12.5

20

6700 2700 4800

43000

12500

5300 1950

3100

39000

16

25

6750 2750 5300

48000

13500

5400 2000

3000

43000

20

31.5

6800 2800 5400

54000

14000

5500 2000

3100

49000

25

40

6900 2900 5400

61000

14500

5700 2100

3150

56000

31.5

50

7050 2950 5500

70000

17000

5850 2150

3350

65000

40

63

7100 3000 5700

82000

18000

6100 2200

3450

75000

50

80

7400 3100 5800

97000

20500

6250 2300

3700

90000

63

100

7800 3250 6100

118000

25500

6800 2450

4000

109000

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7

8

9

10

Fig. 42

Ohne Namen-1

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Power Transformers above 100 MVA

The power rating range above 100 MVA comprises mainly generator transformers and system-interconnecting transformers with off-load and/or on-load tap changers. Depending on the on-site requirements, they can be designed as transformers with separate windings or as autotransformers, threeor single-phase, for power ratings up to over 1000 MVA and voltages up to 1500 kV. We manufacture these units according to IEC 76, VDE 0532 or other national specifications. Offers for transformers larger than 100 MVA only on request.

1

2

3

4

5

6 Fig. 43: Coal-fired power station in Germany with two 850-MVA generator transformers: Low-noise design, extended setting range and continuous overload capacity up to 1100 MVA

7 7

8

9

10

1 2 3 4 5 6 7 8 9 10 11 12 13

12 Five-limb core LV winding HV winding Tapped winding Tap leads LV bushings HV bushings Clamping frame On-load tap changer Motor drive Schnabel-car-tank Conservator Water-cooling system 9 1

6

8

11

13

10 3 2

5 4

Fig. 44: View into an 850/1100-MVA generator transformer

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Power Transformers Monitoring System

Siemens Monitoring System: Efficient Condition Recording and Diagnosis for Power Transformers

1

2

Complete acquisition and evaluation of up to 45 measured variables, automatic trend analysis, diagnosis and early warning – the new Siemens Monitoring System makes use of all possible ways of monitoring power transformers: Round the clock, with precision sensors for voltage, temperature or quality of insulation, and with powerful software for measured data processing, display or documentation – with on-line communication over any distance. Maintenance and utilization of power transformers are made more efficient all-round. Because the comprehensive information provided on the condition of the equipment and auxiliaries ensures that maintenance is carried out just where it's needed, costly routine inspections are a thing of the past. And because the maintenance is always preventive, faults are reliably ruled out. All these advantages enhance availability – and thus ensure a long service life of your power transformers. This applies equally to new and old transformers. Equipping new transformers with the Siemens Monitoring System ensures that right from the start the user is in possession of all essential data–for quick, comprehensive analysis. And retrofitting on transformers already in service for considerable periods pays off as well. Particularly in the case of old transformers, constant monitoring significantly reduces the growing risk of failure. Offers for transformers larger 100 MVA only on request.

3

4

5

6

7

8

9 Fig. 45: An integrated solution – the complete Monitoring System housed in a cubicle of the transformer itself

10

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On-load Tap Changers

1

2

3

4

5

6

7

8

9

10

The on-load tap changers installed in Siemens power transformers are manufactured by Maschinenfabrik Reinhausen (MR). MR is a supplier of technically advanced on-load tap changers for oil-immersed power transformers covering an application range from 100 A to 4,500 A and up to 420 kV. About 90,000 MR high-speed resistor-type tap changers are succesfully in service worldwide. The great variety of tap changer models is based on a modular system which is capable of meeting the individual customer’s specifications for the respective operating conditions of the transformer. Depending on the required application range selector, switches or diverter switches with tap selectors can be used, both available for neutral, delta or single-pole connection. Up to 107 operating positions can be achieved by the use of a multiple course tap selector. In addition to the well-known on-load tapchanger for installation in oil-immersed transformers, MR offers also a standardized gas-insulated tap changer for indoor installation which will be mounted on drytype transformers up to approx. 30 MVA and 36 kV, or SF6-type transformers up to 40 MVA and 123 kV. The main characteristics of MR products are: ■ Compact design ■ Optimum adaption and economic solutions offered by the great number of variants ■ High reliability ■ Long life ■ Reduced maintenance ■ Service friendliness The tap changers are mechanically driven – via the drive shafts and the bevel gear – by a motor drive attached to the transformer tank. It is controlled according to the step-by-step principle. Electrical and mechanical safety devices prevent overrunning of the end positions. Further safety measures, such as the automatic restart function, a safety circuit to prevent false phase sequence and running through positions, ensure the reliable operation of motor drives.

For operation under extremely onerous conditions an oil filter unit is available for filtering or filtering and drying of the switching oil. Voltage monitoring is effected by microprocessor-controlled operation control systems or voltage regulators which include a great variety of data input and output facilities. In combination with a parallel control unit, several transformers connected in parallel can be automatically controlled and monitored. Furthermore, Maschinenfabrik Reinhausen offers a worldwide technical service to maintain their high quality standard. Inspections at regular intervals with only small maintenance requirements guarantee the reliable operation expected with MR products.

Type VT Fig. 46: MR motor drive ED 100 S

Type V

Type H

Fig. 47: Gas-insulated on-load tap changer

Type M

Type G

Fig. 48: Selection of on-load tap changers from the MR product range

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Cast-resin Dry-type Transformers, GEAFOL

Standards and regulations GEAFOL® cast-resin dry-type transformers comply with IEC recommendation No. 726, CENELEC HD 464, HD 538 and DIN 42 523. Advantages and applications GEAFOL distribution and power transformers in ratings from 100 to more than 20 000 kVA and LI values up to 170 kV are full substitutes for oil-immersed transformers with comparable electrical and mechanical data. GEAFOL transformers are designed for indoor installation close to their point of use at the center of the major consumers.

They only make use of flame-retardent inorganic insulating materials which free these transformers from all restrictions that apply to oil-filled electrical equipment, such as oil-collecting pits, fire walls, fireextinguishing equipment, etc. GEAFOL transformers are installed wherever oil-filled units cannot be used: inside buildings, in tunnels, on ships, cranes and offshore platforms, in ground-water catchment areas, in food processing plants, etc. Often they are combined with their primary and secondary switchgear and distribution boards into compact substations that are installed directly at their point of use. As thyristor-converter transformers for variable speed drives they can be installed together with the converters at the drive

location. This reduces civil works, cable costs, transmission losses, and installation costs. GEAFOL transformers are fully LI-rated. They have similar noise levels to comparable oil-filled transformers. Taking the above indirect cost reductions into account, they are also frequently cost-competitive. By virtue of their design, GEAFOL transformers are completely maintenance-free for their lifetime. GEAFOL transformers have been in successful service since 1965. A lot of licenses have been granted to major manufactures throughout the world since.

1

2

3

4 Three-leg core

LV terminals Normal arrangement: Top, rear Special version: Bottom, available on request at extra charge

Made of grain-oriented, low-loss electrolaminations insulated on both sides

HV terminals

To insulate core and windings from mechanical vibrations, resulting in low noise emissions

Resilient spacers

Variable arrangements, for optimal station design. HV tapping links on lowvoltage side for adjustment to system conditions, reconnectable in de-energized state Permitting a 50% increase in the rated power

LV winding Temperature monitoring

Made of aluminum strip. Turns firmly glued together by means of insulating sheet wrapper material

By PTC thermistor detectors in the LV winding

Paint finish on steel parts Multiple coating, RAL 5009. On request: Two-component varnish or hot-dip galvanizing (for particularly aggressive environments)

Insulation: Mixture of epoxy resin and quartz powder Makes the transformer maintenance-free, moisture-proof, tropicalized, flame-resistant and selfextinguishing

Ambient class E2 Climatic category C2 (If the transformer is installed outdoors, degree of protection IP 23 must be assured)

Clamping frame and truck Rollers can be swung around for lengthways or sideways travel

Fire class F1

* on-load tap changers on request.

Fig. 49: GEAFOL cast-resin dry-type transformer

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6

HV winding Consisting of vacuumpotted single foil-type aluminum coils. See enlarged detail in Fig. 50

Cross-flow fans

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22.09.1999, 16:25 Uhr

7

8

9

10

Cast-resin Dry-type Transformers, GEAFOL

HV winding

1

2

3

4

5

6

7

8

9

10

The high-voltage windings are wound from aluminum foil, interleaved with highgrade polypropylene insulating foil. The assembled and connected individual coils are placed in a heated mold, and are potted in a vaccum furnace with a mixture of pure silica (quartz sand) and specially blended epoxy resins. The only connections to the outside are copper bushings, which are internally bonded to the aluminum winding connections. The external star or delta connections are made of insulated copper connectors to guarantee an optimal installation design. The resulting high-voltage windings are fire-resistant, moistureproof, corrosionproof, and show excellent aging properties under all indoor operating conditions. (For outdoor use, specially designed sheetmetal enclosures are available.) The foil windings combine a simple winding technique with a high degree of electrical safety. The insulation is subjected to less electrical stress than in other types of windings. In a conventional round-wire winding, the interturn voltage can add up to twice the interlayer voltage, while in a foil winding it never exeeds the voltage per turn because a layer consists of only one winding turn. Result: a high AC voltage and impulse-voltage withstand capacity. Why aluminum? The thermal expansion coefficients of aluminum and cast resin are so similar that thermal stresses resulting from load changes are kept to a minimum (see Fig. 50).

8 8

U

7

1

7 6 5

LV winding

4

The standard low-voltage winding with its considerably reduced dielectric stresses is wound from single aluminum sheets with interleaved cast-resin impregnated fiberglass fabric. The assembled coils are then oven-cured to form uniformly bonded solid cylinders that are impervious to moisture. Through the single-sheet winding design, excellent dynamic stability under short-circuit conditions is achieved. Connections are submerged-arc-welded to the aluminum sheets and are extended either as aluminum or copper busbars to the secondary terminals.

Round-wire winding

6 4

3

3

2

2

2

8

3

7

4

6 5

1

Strip winding

U

2 4 6 8

2

3

4

5

6

7

8

1

2

3

4

5

6

7

1 3 5 7

Fig. 50: High-voltage encapsulated winding design of GEAFOL cast-resin transformer and voltage stress of a conventional round-wire winding (above) and the foil winding (below)

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Cast-resin Dry-type Transformers, GEAFOL

Fire safety GEAFOL transformers use only flameretardent and self-extinguishing materials in their construction. No additional substances, such as aluminum oxide trihydrate, which could negatively influence the mechanical stability of the cast-resin molding material, are used. Internal arcing from electrical faults and externally applied flames do not cause the transformers to burst or burn. After the source of ignition is removed, the transformer is self-extinguishing. This design has been approved by fire officials in many countries for installation in populated buildings and other structures. The environmental safety of the combustion residues has been proven in many tests. Categorization of cast-resin transformers Dry-type transformers have to be categorized under the sections listed below: ■ Environmental category ■ Climatic category ■ Fire category These categories have to be shown on the rating plate of each dry-type transformer.

The properties laid down in the standards for ratings within the approximate category relating to environment (humidity), climate and fire behavior have to be demonstrated by means of tests. These tests are described for the environmental category (code number E0, E1 and E2) and for the climatic category (code number C1, C2) in DIN VDE 0532 Part 6 (corresponding to HD 464). According to this standard, they are to be carried out on complete transformers. The tests of fire behavior (fire category code numbers F0 and F1) are limited to tests on a duplication of a complete transformer. It consists of a core leg, a low-voltage winding and a high-voltage winding. The specifications for fire category F2 are determined by agreement between the manufacturer and the customer. Siemens have carried out a lot of tests. The results for our GEAFOL transformers are something to be proud of: ■ Environmental category E2 ■ Climatic category C2 ■ Fire category F1 This good behavior is solely due to the GEAFOL cast-resin mix which has been used successfully for decades.

Insulation class and temperature rise The high-voltage winding and the lowvoltage winding utilize class F insulating materials with a mean temperature rise of 100 K (standard design).

1

Overload capability

2

GEAFOL transformers can be overloaded permanently up to 50% (with a corresponding increase in impedance voltage) if additional radial cooling fans are installed. (Dimensions increase by approximately 200 mm in length and width.) Short-time overloads are uncritical as long as the maximum winding temperatures are not exceeded for extended periods of time.

4

Temperature monitoring Each GEAFOL transformer is fitted with three temperature sensors installed in the LV winding, and a solid-state tripping device with relay output. The PTC thermistors used for sensing are selected for the applicable maximum hot-spot winding temperature. Additional sets of sensors with lower temperature points can be installed for them and for fan control purposes. Additional dial-type thermometers and Pt100 are available, too. For operating voltages of the LV winding of 3.6 kV and higher, special temperature measuring equipment can be provided. Auxiliary wiring is run in protective conduit and terminated in a central LV terminal box (optional). Each wire and terminal is identified, and a wiring diagram is permanently attached to the inside cover of this terminal box.

Indoor installation in electrical operating rooms or in various sheet-metal enclosures is the preferred method of installation. The transformers need only be protected against access to the terminals or the winding surfaces, against direct sunlight, and against water. Sufficient ventilation must be provided by the installation location or the enclosure. Otherwise forced-air cooling must be specified or provided by others.

Fig. 51: Flammability test of cast-resin transformer

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5

6

7

8

Installation and enclosures

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

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9

10

Cast-resin Dry-type Transformers, GEAFOL

1

2

3

4

5

6

7

Instead of the standard open terminals, insulated plug-type elbow connectors can be supplied for the high-voltage side with LI ratings up to 170 kV. Primary cables are usually fed to the transformer from trenches below, but can also be connected from above. Secondary connections can be made by multiple insulated cables, or by busbars, from either below or above. Secondary terminals are either aluminum or copper busbar stubs, drilled to specification. A variety of indoor and outdoor enclosures in different protection classes are available for the transformers alone, or for indoor compact substations in conjunction with high- and low-voltage switchgear cubicles. Recycling of GEAFOL transformers Of all the GEAFOL transformers manufactured since 1965, even the oldest units are not about to reach the end of their service life expectancy. In spite of this, a lot of experiences have been made over the years with the recycling of coils that have become unusable due to faulty manufacture or damage. These experiences show that all the metallic components, i.e. approx. 90% of all materials, can be fully recovered economically. The recycling method used by Siemens does not pollute the environment. In view of the value of the secondary raw materials, the procedure can be economical even considering the currently small amounts.

Fig. 52: GEAFOL transformer with plug-type cable connections

8

9

10

Fig. 53: Radial cooling fans on GEAFOL transformer for AF cooling

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Fig. 54: GEAFOL transformer in protective housing to IP 20/40

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GEAFOL Cast-resin Selection Tables, Technical Data, Dimensions and Weights

■ ■ ■ ■ ■

■ ■ ■

■ ■ ■

Standard: DIN 42523 Rated power: 100–20000 kVA* Rated frequency: 50 Hz HV rating: up to 36 kV LV rating: up to 780 V; special designs for up to 12 kV are possible Tappings on ± 2.5 % or ± 2 x 2.5 % HV side: Connection: HV winding: delta LV winding: star Impedance 4–8 % voltage at rated current: Insulation class: HV/LV = F/F Temperature HV/LV = 100/100 K rise: Color of metal RAL 5009 (other parts: colors are available)

Um [kV]

LJ [kV]

AC [kV]

1.1

–

3

12

75

28

24

95**

50

36

145**

70

1

* power rating > 2.5 MVA upon request ** other levels upon request

2

Fig. 55: Insulation level

2U

2V

2N

2W

3 H1

4 E B1

E A1

5

Fig. 56: GEAFOL cast-resin transformer

Rated power

Rated Impevoltage dance voltage

Type

Sound power level

Total weight

Pk 75* [W]

Sound Load losses press. level 1m tolerance + 3 dB Pk 120** LPA [W] [dB]

LWA [dB]

GGES [kg]

A1 [mm]

B1 [mm]

No-load Load losses losses

Width

Height

Distance between wheel centers

6

Sn [kVA]

Um [kV]

U2 [%]

4GB…

100

12

4

.5044-3CA

440

1600

1900

45

59

630

1210

705

835

without wheels

4

.5044-3GA

320

1600

1900

37

51

760

1230

710

890

without wheels

6

.5044-3DA

360

2000

2300

45

59

590

1190

705

860

without wheels

6

.5044-3HA

300

2000

2300

37

51

660

1230

710

855

without wheels

4

.5064-3CA

600

1500

1750

45

59

750

1310

755

935

without wheels

4

.5064-3GA

400

1500

1750

37

51

830

1300

755

940

without wheels

6

.5064-3DA

420

1800

2050

45

59

660

1250

750

915

without wheels

6

.5064-3HA

330

1800

2050

37

51

770

1300

755

930

without wheels

4

.5244-3CA

610

2300

2600

47

62

770

1220

710

1040

520

4

.5244-3GA

440

2300

2600

39

54

920

1290

720

1050

520

6

.5244-3DA

500

2300

2700

47

62

750

1270

720

990

520

6

.5244-3HA

400

2300

2700

39

54

850

1300

725

985

520

4

.5264-3CA

800

2200

2500

47

62

910

1330

725

1090

520

4

.5264-3GA

580

2200

2500

39

54

940

1310

720

1095

520

6

.5264-3DA

600

2500

2900

47

62

820

1310

725

1075

520

6

.5264-3HA

480

2500

2900

39

54

900

1350

765

1060

520

24

160

12

24

P0 [W]

Dimensions Length

H1 [mm]

E [mm]

7

Dimensions and weights are approximate values and valid for 400 V on the secondary side, vector-group can be Dyn 5 or Dyn 11. * In case of short-circuits at 75 °C ** In case of short-circuits at 120 °C

Fig. 57: GEAFOL cast-resin transformers 50 to 2500 kVA

Ohne Namen-1

31

5/31

22.09.1999, 16:26 Uhr

9

10

Rated power figures in parentheses are not standardized.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

8

GEAFOL Cast-resin Selection Tables, Technical Data, Dimensions and Weights

1

2

Rated power

Rated Impevoltage dance voltage

Sn [kVA]

Um [kV]

U2 [%]

250

12

4

.5444-3CA

4

.5444-3GA

6 6

Sound power level

Total weight

Pk 75* [W]

LWA [dB]

GGES [kg]

820

3000

3500

50

65

600

3000

3400

42

57

.5444-3DA

700

2900

3300

50

.5444-3HA

570

2900

3300

4

.5464-3CA

1050

2900

4

.5464-3GA

800

2900

6

.5464-3DA

880

6

.5464-3HA

36

6

12

4

24

4

5 24

6

7

400

9 (500)

Dimensions Length

Width

Height

Distance between wheel centers

A1 [mm]

B1 [mm]

H1 [mm]

E [mm]

1040

1330

730

1110

520

1170

1330

730

1135

520

65

990

1350

740

1065

520

42

57

1120

1390

745

1090

520

3300

50

65

1190

1390

735

1120

520

3300

41

57

1230

1400

735

1150

520

3100

3600

50

65

990

1360

735

1140

520

650

3100

3600

41

57

1180

1430

745

1160

520

.5475-3DA

1300

3800

4370

50

65

1700

1900

900

1350

520

.5544-3CA

980

3300

3800

52

67

1160

1370

820

1125

670

4

.5544-3GA

720

3300

3800

43

59

1320

1380

820

1195

670

6

.5544-3DA

850

3400

3900

51

67

1150

1380

830

1140

670

6

.5544-3HA

680

3400

3900

43

59

1290

1410

830

1165

670

4

.5564-3CA

1250

3400

3900

51

67

1250

1410

820

1195

670

4

.5564-3GA

930

3400

3900

43

59

1400

1440

825

1205

670

6

.5564-3DA

1000

3600

4100

51

67

1190

1410

825

1185

670

4GB…

P0 [W]

6

.5564-3HA

780

3600

4100

43

59

1300

1460

830

1195

670

36

6

.5575-3DA

1450

4500

5170

51

67

1900

1950

920

1400

670

12

4

.5644-3CA

1150

4300

4900 52

68

1310

1380

820

1265

670

4

.5644-3GA

880

4300

4900 44

60

1430

1380

820

1290

670

6

.5644-3DA

1000

4300

4900 52

68

1250

1410

825

1195

670

6

.5644-3HA

820

4300

4900 44

60

1350

1430

830

1195

670

4

.5664-3CA

1450

3900

4500 52

68

1410

1440

825

1280

670

4

.5664-3GA

1100

3900

4500 44

60

1570

1460

830

1280

670

6

.5664-3DA

1200

4100

4700 52

68

1350

1480

835

1275

670

6

.5664-3HA

940

4100

4700 44

60

1460

1480

835

1280

670

36

6

.5675-3DA

1700

5100

5860 52

68

2100

2000

920

1440

670

12

4

.5744-3CA

1350

4900

5600 53

69

1520

1410

830

1320

670

4

.5744-3GA

1000

4900

5600 45

61

1740

1450

835

1345

670

6

.5744-3DA

1200

5600

6400 53

69

1470

1460

845

1275

670

6

.5744-3HA

980

5600

6400 45

61

1620

1490

845

1290

670

4

.5764-3CA

1700

4800

5500 53

69

1620

1500

835

1330

670

4

.5764-3GA

1270

4800

5500 44

61

1830

1540

840

1350

670

6

.5764-3DA

1400

5000

5700 53

69

1580

1540

850

1305

670

6

.5764-3HA

1100

5000

5700 45

61

1720

1560

850

1320

670

6

.5775-3DA

1900

6000

6900 53

69

2600

2050

940

1500

670

24

8

No-load Load losses losses

Sound Load losses press. level 1m tolerance + 3 dB Pk 120** LPA [W] [dB]

3

(315)

Type

10 24

36

Dimensions and weights are approximate values and valid for 400 V on the secondary side, vector-group can be Dyn 5 or Dyn 11.

Rated power figures in parentheses are not standardized.

* In case of short-circuits at 75 °C ** In case of short-circuits at 120 °C

Fig. 58: GEAFOL cast-resin transformers 50 to 2500 kVA

5/32

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32

22.09.1999, 16:26 Uhr

GEAFOL Cast-resin Selection Tables, Technical Data, Dimensions and Weights

Rated power

Rated Impevoltage dance voltage

Sound power level

Total weight

Sn [kVA]

Um [kV]

U2 [%]

4GB…

P0 [W]

LWA [dB]

630

12

4

.5844-3CA

1500

6400

7300

54

4

.5844-3GA

1150

6400

6

.5844-3DA

1370

6400

7300 7400

6

.5844-3HA

1150

6400

4

.5864-3CA

1950

4 6

.5864-3GA .5864-3DA

6 36

6

12

24

(800)

24

1000

No-load Load losses losses

Length

Width

Height

Distance between wheel centers

GGES [kg]

A1 [mm]

B1 [mm]

H1 [mm]

E [mm]

70

1830

1510

840

1345

670

45

62

2070

1470

835

1505

670

54

70

1770

1550

860

1295

670

7400

45

62

1990

1590

865

1310

670

6000

6900

53

70

1860

1550

845

1380

670

1500

6000

6900

45

62

2100

1600

850

1400

670

1650

6400

7300

53

70

1810

1580

855

1345

670

.5864-3HA

1250

6400

7300

45

62

2050

1620

860

1370

670

.5875-3DA

2200

7000

8000

53

70

2900

2070

940

1650

670

4

.5944-3CA

1850

7800

9000

55

72

2080

1570

850

1560

670

4

.5944-3GA

1450

7800

9000

47

64

2430

1590

855

1640

670

6

.5944-3DA

1700

7600

8700

55

72

2060

1560

865

1490

670

6

.5944-3HA

1350

7600

8700

47

64

2330

1600

870

1530

670

4

.5964-3CA

2100

7500

8600

55

72

2150

1610

845

1580

670

4

.5964-3GA

1600

7500

8600

47

64

2550

1650

855

1620

670

6

.5964-3DA

1900

7900

9100

55

71

2110

1610

860

1590

670

6

.5964-3HA

1450

7900

9100

47

64

2390

1630

865

1595

670

Pk 75* [W]

Sound Load losses press. level 1m tolerance + 3 dB Pk 120** LPA [W] [dB]

Dimensions

36

6

.5975-3DA

2600

8200

9400

55

72

3300

2140

950

1850

670

12

4

.6044-3CA

2200

8900 10200

55

73

2480

1590

990

1775

820

4

.6044-3GA

1650

8900 10200

47

65

2850

1620

990

1795

820

6

.6044-3DA

2000

8500

9700

56

73

2420

1620

990

1560

820

6

.6044-3HA

1500

8500

9700

47

65

2750

1660

990

1560

820

4

.6064-3CA

2400

8700 10000

55

73

2570

1660

990

1730

820

4

..6064-3GA

1850

8700 10000

47

65

3060

1680

990

1815

820

6

.6064-3DA

2300

9200 10500

55

73

2510

1680

990

1620

820

24

(1250)

Type

6

.6064-3HA

1750

9600 11000

47

65

2910

1730

990

1645

820

36

6

.6075-3DA

3000

9500 10900

55

73

3900

2200

1050

1900

820

12

6

.6144-3DA

2400

9600 11000

57

75

2900

1780

990

1605

820

6

.6144-3HA

1850

10500 12000

49

67

3370

1790

990

1705

820

6

.6164-3DA

2700

10000 11500

57

75

3020

1820

990

1635

820

6

.6164-3HA

2100

10500 12000

49

67

3490

1850

990

1675

820

6

.6175-3DA

3500

11000 12600

57

75

4500

2300

1060

2000

520

24 36

Dimensions and weights are approximate values and valid for 400 V on the secondary side, vector-group can be Dyn 5 or Dyn 11.

1

2

3

4

5

6

7

8

9

10

Rated power figures in parentheses are not standardized.

* In case of short-circuits at 75 °C ** In case of short-circuits at 120 °C

Fig. 59: GEAFOL cast-resin transformers 50 to 2500 kVA

5/33

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Ohne Namen-1

33

22.09.1999, 16:26 Uhr

GEAFOL Cast-resin Selection Tables, Technical Data, Dimensions and Weights

1

2

Total weight

LWA [dB]

58

11400 13000

3100 2400

.6275-3DA

6

No-load Load losses losses

Sound Load losses press. level 1m tolerance + 3 dB

Length

Height

Distance between wheel centers

GGES [kg]

A1 [mm]

B1 [mm]

H1 [mm]

E [mm]

76

3550

1840

995

2025

1070

50

68

4170

1880

1005

2065

1070

11800 13500

58

76

3640

1880

995

2035

1070

12300 14000

49

68

4080

1900

1005

2035

1070

4300

12700 14600

58

76

5600

2500

1100

2400

1070

.6344-3DA

3600

14000 16000

59

78

4380

1950

1280

2150

1070

6

.6344-3HA

2650

14500 16500

51

70

5140

1990

1280

2205

1070

6

.6364-3DA

4000

14500 16500

59

78

4410

2020

1280

2160

1070

6

.6364-3HA

3000

14900 17000

51

70

4920

2040

1280

2180

1070

36

6

.6375-3DA

5100

15400 17700

59

78

6300

2500

1280

2400

1070

12

6

.6444-3DA

4300

17600 20000

62

81

5130

2110

1280

2150

1070

6

.6444-3HA

3000

18400 21000

51

71

6230

2170

1280

2205

1070

6

.6464-3DA

5000

17600 20000

61

81

5280

2170

1280

2160

1070

6

.6464-3HA

3600

18000 20500

51

71

6220

2220

1280

2180

1070

6

.6475-3DA

6400

18700 21500

61

81

7900

2700

1280

2400

1070

Sn [kVA]

Um [kV]

U2 [%]

4GB…

P0 [W]

Pk 75* Pk 120** LPA [W] [W] [dB]

1600

12

6

.6244-3DA

2800

11000 12500

6

.6244-3HA

2100

6

.6264-3DA

6

.6264-3HA

36

6

12

24

(2000)

4 24

2500

24

6

36

Dimensions and weights are approximate values and valid for 400 V on the secondary side, vector-group can be Dyn 5 or Dyn 11.

7

Dimensions Width

ImpeRated voltage dance voltage

3

5

Sound power level

Type

Rated power

Rated power figures in parentheses are not standardized.

* In case of short-circuits at 75 °C ** In case of short-circuits at 120 °C Rated power >2500 kVA to 20 MVA on request.

Fig. 60: GEAFOL cast-resin transformers 50 to 2500 kVA

8

9

10

5/34

Ohne Namen-1

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22.09.1999, 16:26 Uhr

Special Transformers

GEAFOL cast-resin transformers with oil-free tap-changers The voltage-regulating cast-resin transformers connected on the load side of the medium-voltage power supply system feed the plant-side distribution transformers. The tap-changer-controlled transformers used in these medium-voltage systems need to have appropriately high ratings. Siemens offers suitable transformers in its GEAFOL design which has proved successful over many years and is available in ratings of up to 20 MVA. With forced cooling it is even possible to increase the power ratings still further by 40%. The range of rated voltage extends to 36 kV and the maximum impulse voltage is 200 kV. The main applications of this type of transformer are in modern industrial plants, hospitals, office and appartment blocks and shopping centers.

Linking single-pole tap-changer modules together in threes by means of insulating shafts produces a triple-pole tap-changer in either star or delta connection for regulating the output voltage of GEAFOL transformers. In its nine operating positions, this type of tap-changer has a rated through-current of 500 A and a rated voltage of 900 V per step. This allows voltage fluctuations of up to 8100 V to be kept under control. However, the maximum control range utilizes only 20% of the rated voltage.

1

2

3

4

5

6

7

8

9

10

Fig. 61: 16/22-MVA GEAFOL cast-resin transformer with oil-free on-load tap changer

5/35

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Ohne Namen-1

35

22.09.1999, 16:26 Uhr

Special Transformers

1

2

3

4

5

6

Transformers for thyristor converters These are special oil-immersed or castresin power transformers that are designed for the special demands of thyristor converter or diode rectifier operation. The effects of such conversion equipment on transformers and additional construction requirements are as follows: ■ Increased load by harmonic currents ■ Balancing of phase currents in multiple winding systems (e.g. 12-pulse systems) ■ Overload factor up to 2.5 ■ Types for 12-pulse systems, if required. Siemens supplies oil-filled converter transformers of all ratings and configurations known today, and dry-type cast-resin converter transformers up to more than 20 MVA and 200 kV LI. To define and quote for such transformers, it is necessary to know considerable details on the converter to be supplied and on the line feeding it. These transformers are almost exclusively inquired together with the respective drive or rectifier system and are always custom-engineered for the given application.

Neutral grounding transformers 7

8

9

10

When a neutral grounding reactor or ground-fault neutralizer is required in a three-phase system and no suitable neutral is available, a neutral must be provided by using a neutral grounding transformer. Neutral grounding transformers are available for continuous operation or short-time operation. The zero impedance is normally low. The standard vector groups are zigzag or wye/delta. Some other vector groups are also possible. Neutral grounding transformers can be built by Siemens in all common power ratings. Normally, the neutral grounding transformers are built in oil-immersed design, however, they can also be built in cast-resin design.

5/36

Ohne Namen-1

Fig. 62: Dry-type converter transformer GEAFOL

For further information please contact: Distribution transformers: Fax: ++49-7021-508548 Power transformers: Fax: ++49-911-4342147

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

36

22.09.1999, 16:27 Uhr

Protection and Substation Control Contents

Page

Local and Remote Control Introduction ................................. 6/71 SINAUT LSA Overview ...................................... 6/74 SINAUT LSA Substation automation distributed structure .................. 6/78 SINAUT LSA Substation automation centralized structure (Enhanced RTU) .......................... 6/91 SINAUT LSA Compact remote terminal units .............................. 6/93 SICAM Overview ........................ 6/96 SICAM RTU Remote terminal units (RTUs) ................................. 6/97 SICAM SAS Substation automation ............ 6/108 SICAM PCC Substation automation ............ 6/118

Contents

Device dimensions .................. 6/125

Page

General overview ........................ 6/2

Power Quality

Application hints ......................... 6/4

Introduction ............................... 6/131

Power System Protection

Measuring and recording ...... 6/132

Introduction ................................... 6/8

Compensation systems Introduction ............................... 6/146

Relay selection guide ................ 6/22

Passive compensation systems ...................................... 6/147

Relay portraits ............................ 6/25 Typical protection schemes ..... 6/42

Active compensation systems ...................................... 6/154

Protection coordination ............ 6/62

6

Protection and Substation Control General Overview

General overview 1

2

3

Three trends have emerged in the sphere of substation secondary equipment: intelligent electronic devices (IEDs), open communication and operation with a PC. Numerical relays and cumputerized substation control are now state-of-the-art. The multitude of conventional, individual devices prevalent in the past as well as comprehensive parallel wiring are being replaced by a small number of multifunctional devices with serial connections.

System control centers IEC 60870-5-101 SICAM WinCC

SICAM plusTools

GPS

Monitoring and control PROFIBUS

Engineering, Parameterizing

Automation

Wire RS485

IEC 60 870-5-103 SIPROTEC-IEDs: – Relays O.F. – Bay control units – Transducers – etc.

One design for all applications

4

5

6

7

In this respect, Siemens offers a uniform, universal technology for the entire functional scope of secondary equipment, both in the construction and connection of the devices and in their operation and communication. This results in uniformity of design, coordinated interfaces and the same operating concept being established throughout, whether in power system and generator protection, in measurement and recording systems, in substation control and protection or in telecontrol. All devices are highly compact and immune to interference, and are therefore also suitable for direct installation in switchgear cells. Furthermore, all devices and systems are largely self-monitoring, which means that previously costly maintenance can be reduced considerably.

Fig. 1: The digital substation control system SICAM implements all of the control, measurement and automation functions of a substation. Protection relays are connected serially

“Complete technology from one partner“

8

9

10

The Protection and Substation Control Systems Division of the Siemens Power Transmission and Distribution Group supplies devices and systems for: ■ Power System Protection ■ Substation Control ■ Remote Control (RTUs) ■ Measurement and Recording ■ Monitoring and Conditioning of Power Quality This covers all of the measurement, control, automation and protection functions for substations*. Furthermore, our activities cover: ■ Consulting ■ Planning ■ Design ■ Commissioning and Service This uniform technology ”all from one source“ saves the user time and money in the planning, assembly and operation of his substations. *An exception is revenue metering. Meters are separate products of our Metering Division.

6/2

Fig. 2a: Protection and control in HV GIS switchgear

Fig. 2b: Protection and control in bay dedicated kiosks of an EHV switchyard

Rationalization of operation

by means of SCADA-like operation control and high-performance, uniformly operable PC tools

Savings in terms of space and costs

by means of integration of many functions into one unit and compact equipment design

Simplified planning and operational reliability

by means of uniform design, coordinated interfaces and universally identical EMC

Efficient parameterization and operation

by means of PC tools with uniform operator interface

High levels of reliability and availability

by means of type-tested system technology, complete self-monitoring and the use of proven technology – 20 years of practical experience with digital protection, more than 150,000 devices in operation (1999) – 15 years of practical experience with substation automation (SINAUT LSA and SICAM), over 1500 substations in operation (1999)

Fig. 3: For the user, “complete technology from one source” has many advantages

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Protection and Substation Control General Overview

1

Protection and substation automation

Substation automation SICAM/SINAUT LSA

SINAUT LSA

SICAM SAS

Substation automation systems, centralized and decentralized

Substation automation systems, LAN-based (Profibus)

Protection SIPROTEC

Power quality SIMEAS/SIPCON

Feeder protection overcurrent/overload relays

SIMEAS R

7SJ5 and 7SJ6

Energy automation based on PC and LAN (Profibus)

SICAM RTU Enhanced RTU 6MD2010

SINAUT LSA

3

4

Power quality recorders

7SA5

SICAM PCC

Fault recorders (Oscillostores)

SIMEAS Q, M, N

Line protection distance relays Remote terminal units

2

Line protection pilot protection relays

SIMEAS T

7SD5

Measuring transducers

Transformer protection

SIPCON

7UT5

Power conditioners

5

6

Compact unit

6MB552

Generator/motor protection

Minicompact unit

7UM5

6MB553

7 Busbar protection 7SS5 and 7VH8

8

Fig. 4: Siemens Protection and Substation Control comprises these systems and product ranges

System Protection Siemens offers a complete spectrum of multifunctional, numerical relays for all applications in the field of network and machine protection. Uniform design and electromagnetic-interference-free construction in metal housings with conventional connection terminals in accordance with public utility requirements assure simple system design and usage just as with conventional relays. Numerical measurement techniques ensure precise operation and necessitate less maintenance thanks to their continuous self-monitoring capability.

The integration of additional protection and other functions, such as real-time operational measurements, event and fault recording, all in one unit economizes on space, design and wiring costs. Setting and programming of the devices can be performed through the integral, plaintext, menu-guided operator display or by using the comfortable PC program DIGSI for Windows*. Open serial interfaces, IEC 870-5-103-compliant, allow free communication with higher level control systems, including those from other manufacturers. Connection to a Profibus substation LAN is optionally possible.

Thus the on-line measurements and fault data registered in the protective relays can be used for local and remote control or can be transmitted via telephone modem connections to the workplace of the service engineer. Siemens supplies individual devices as well as complete protection systems in factory finished cubicles. For complex applications, for example, in the field of extrahigh-voltage transmission, type and design test facilities are available together with an extensive and comprehensive network model using the most modern simulation and evaluation techniques.

* Windows is a registered product of Microsoft

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

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Protection and Substation Control General Overview

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Substation control

Switchgear interlocking

Advantages for the user

The digital substation control systems SICAM and SINAUT LSA provide all control, measurement and automation functions (e.g. transformer tap changing) required by a switching station. They operate with distributed intelligence. Communication between feeder-located devices and central unit is made via interferencefree fiber optic connections. Devices are extremely compact and can be built directly into medium and high-voltage switchgear. To input data, set and program the system, the unique PC programs SICAM PlusTools and LSA-TOOLS are available. Parameters and values are input at the central unit and downloaded to the field devices, thus ensuring error-free and consistent data transfer. The operator interface is menu-guided, with SCADA comparable functions, that is, with a level of convenience which was previously only available in a network control center. Optional telecontrol functions can be added to allow coupling of the system to one or more network control centers. In contrast to conventional controls, digital technology saves enormously on space and wiring. SICAM and LSA systems are subjected to full factory tests and are delivered in fully functional condition.

The digital interlocking system 8TK is used for important substations in particular with multiple busbar arrangements. It prevents false switching and provides an additional local bay control function which allows failsafe switching, even when the substation control system is not available. Therefore the safety of operating personnel and equipment is considerabely enhanced. The 8TK system can be used as a standalone interlocked control, or as back-up system together with the digital 6MB substation control.

The concept of ”Complete technology from one partner“ offers the user many advantages: ■ High-level security for his systems and operational rationalization possibilities – powerful system solutions with the most modern technology – compliance with international standards ■ Integration in the overall system SIPROTEC-SICAM-SIMATIC ■ Space and cost savings – integration of many functions into one unit and compact equipment packaging ■ Simple planning and secure operation – unified design, matched interfaces and EMI security throughout ■ Rationalized programming and handling – menu-guided PC Tools and unified keypads and displays ■ Fast, flexible mounting, reduced wiring ■ Simple, fast commissioning ■ Effective spare part stocking, high flexibility ■ High-level operational security and availability – continuous self-monitoring and proven technology: – 20 years digital relay experience (more than 150,000 units in operation) – 10 years of SINAUT LSA and SICAM substation control (more than 1500 systems in operation) ■ Rapid problem solving – comprehensive advice and fast response from local sales and workshop facilities worldwide.

Remote control Siemens remote control equipment 6MB55* and 6MD2010 fulfills all the classic functions of remote measurement and control. Furthermore, because of the powerful microprocessors with 32-bit technology, they provide comprehensive data preprocessing, automation functions and bulk storage of operational and fault information. In the classic case, connections to the switchgear are made through coupling relays and transducers. This method allows an economically favorable solution when modernizing or renewing the secondary systems in older installations. Alternatively, especially for new installations, direct connection is also possible. Digital protection devices can be connected by serial links through fiber-optic conductors. In addition, the functions ”operating and monitoring“ can be provided by the connection of a PC, thus raising the telecontrol unit to the level of a central station control system. Using the facility of nodal functions, it is also possible to build regional control points so that several substations can be controlled from one location.

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Power Quality (Measurement, recording and power compensation) The SIMEAS product range offers equipment for the superversion of power supply quality (harmonic content, distortion factor, peak loads, power factor, etc.), fault recorders (Oscillostore), data logging printers and measurement transducers. Stored data can be transmitted manually or automatically to PC evaluation systems where it can be analyzed by intelligent programs. Expert systems are also applied here. This leads to rapid fault analysis and valuable indicators for the improvement of network reliability. For local bulk data storage and transmission, the central processor DAKON can be installed at substation level. Data transmission circuits for analog telephone or digital ISDN networks are incorporated as standard. Connection to local or wide-area networks (LAN, WAN) is equally possible. We also have the SIMEAS T series of compact and powerful measurement transducers with analog and digital outputs. The SIPCON Power Conditioner solves numerous system problems. It compensates (for example) unbalanced loads or system voltage dips and suppresses system harmonics. It performs these functions so that sensitive loads are assured of suitable voltage quality at all times. In addition, the system ist also capable of eliminating the perturbation produced by irregular loads. The use of SIPCON can enable energy suppliers worldwide to provide the end consumer with distinctive quality of supply.

Application hints All named devices and systems for protection, metering and control are designed to be used in the harsh environment of electrical substations, power plants and the various industrial application areas. When the devices were developed, special emphasis was placed on EMI. The devices are in accordance with IEC 60 255 standards. Detailed information is contained in the device manuals. Reliable operation of the devices is not affected by the usual interference from the switchgear, even when the device is mounted directly in a low-voltage compartment of a medium-voltage cubicle.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Protection and Substation Control Application Hints

It must, however, be ensured that the coils of auxiliary relays located on the same panel, or in the same cubicle, are fitted with suitable spike quenching elements (e.g. free-wheeling diodes). When used in conjunction with switchgear for 100 kV or above, all external connection cables should be fitted with a screen grounded at both ends and capable of carrying currents. That means that the cross section of the screen should be at least 4 mm2 for a single cable and 2.5 mm2 for multiple cables in one cable duct. All equipment proposed in this guide is built-up either in closed housings (type 7XP20) or cubicles with protection degree IP 51 according to IEC 60 529: ■ Protected against access to dangerous parts with a wire ■ Sealed against dust ■ Protected against dripping water

Electromagnetic compatibility

All Siemens protection and control products recommended in this guide comply with the EMC Directive 99/336/EEC of the Council of the European Community and further relevant IEC 255 standards on electromagnetic compatibility. All products carry the CE mark.

Vibration and shock during operation ■ Standards:

IEC 60 255-21 and IEC 60068-2 ■ Vibration – sinusoidal IEC 60 255-21-1, class 1 – 10 Hz to 60 Hz: ± 0.035 mm amplitude; IEC 600 68-2-6 – 60 Hz to 150 Hz: 0.5 g acceleration sweep rate 10 octaves/min 20 cycles in 3 orthogonal axes

3

■ Standards:

■

■

■ Permissible temperature during

Mechanical stress

2

EMC tests; immunity (type tests)

Climatic conditions: service –5 °C to +55 °C permissible temperature during storage –25 °C to +55 °C permissible temperature during transport –25 °C to +70 °C Storage and transport with standard works packaging ■ Permissible humidity Mean value per year ≤ 75% relative humidity; on 30 days per year 95% relative humidity; Condensation not permissible We recommend that units be installed such that they are not subjected to direct sunlight, nor to large temperature fluctuations which may give rise to condensation.

1

EC Conformity declaration (CE mark):

■

Fig. 5: Installation of the numerical protection in the door of the low-voltage section of medium-voltage cell ■

Vibration and shock during transport ■ Standards:

IEC 60255-21and IEC 60068-2 ■ Vibration

– sinusoidal IEC 60255-21-1, class 2 – 5 Hz to 8 Hz: ± 7.5 mm amplitude; IEC 60068-2-6 – 8 Hz to 150 Hz: 2 g acceleration sweep rate 1 octave/min 20 cycles in 3 orthogonal axes ■ Shock IEC 60255 -21-2, class 1 IEC 60068 -2-27

■

■

■

Insulation tests ■ Standards:

IEC 60255-5 – High-voltage test (routine test) 2 kV (rms), 50 Hz – Impulse voltage test (type test) all circuits, class III 5 kV (peak); 1.2/50 µs; 0.5 J; 3 positive and 3 negative shots at intervals of 5 s

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

■

IEC 60255-22 (product standard) EN 50082-2 (generic standard) High frequency IEC 60255-22-1 class III – 2.5 kV (peak); 1 MHz; τ = 15 µs; 400 shots/s; duration 2 s Electrostatic discharge IEC 60255-22-2 class III and EN 61 000-4-2 class III – 4 kV contact discharge; 8 kV air discharge; both polarities; 150 pF; Ri = 330 Ohm Radio-frequency electromagnetic field, nonmodulated; IEC 60255-22-3 (report) class III – 10 V/m; 27 MHz to 500 MHz Radio-frequency electromagnetic field, amplitude-modulated; ENV 50140, class III – 10 V/m; 80 MHz to 1000 MHz, 80%; 1 kHz; AM Radio-frequency electromagnetic field, pulse-modulated; ENV 50140/ENV 50 204, class III – 10 V/m; 900 MHz; repetition frequency 200 Hz; duty cycle 50% Fast transients IEC 60255-22-4 and EN 61000-4-4, class III – 2 kV; 5/50 ns; 5 kHz; burst length 15 ms; repetition rate 300 ms; both polarities; Ri = 50 Ohm; duration 1 min Conducted disturbances induced by radio-frequency fields HF, amplitude-modulated ENV 50141, class III – 10 V; 150 kHz to 80 MHz; 80%; 1kHz; AM Power-frequency magnetic field EN 61000-4-8, class IV – 30 A/m continuous; 300 A/m for 3 s; 50 Hz

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7

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10

Protection and Substation Control Application Hints

1

EMC tests; emission (type tests)

Cores for revenue metering

■ Standard:

In this case, class 0.2 M is normally required.

EN 50081-2 (generic standard) ■ Interference field strength CISPR 11,

2

3

4

EN 55011, class A – 30 MHz to 1000 MHz ■ Conducted interference voltage, aux. voltage CISPR 22, EN 55022, class B – 150 kHz to 30 MHz Instrument transformers Instrument transformers must comply with the applicable IEC recommendations IEC 60044, formerly IEC 60185 (c.t.) and 186 (p.t.), ANSI/IEEE C57.13 or other comparable standards. Potential transformers

5

6

Potential transformers (p.t.) in single- or double-pole design for all primary voltages have single or dual secondary windings of 100, 110 or 120 V/ 3, with output ratings between 10 and 300 VA, and accuracies of 0.2, 0.5 or 1% to suit the particular application. Primary BIL values are selected to match those of the associated switchgear. Current transformers

7

8

9

Current transformers (c.t.) are usually of the single-ratio type with wound or bartype primaries of adequate thermal rating. Single, dual or triple secondary windings of 1 or 5 A are standard. 1 A rating however should be preferred, particularly in HV and EHV stations, to reduce the burden of the connecting leads. Output power (rated burden in VA), accuracy and saturation characteristics (accuracy limiting factor) of the cores and secondary windings must meet the particular application. The c.t. classification code of IEC is used in the following: Measuring cores

10

They are normally specified with 0.5% or 1.0% accuracy (class 0.5 M or 1.0 M), and an accuracy limiting factor of 5 or 10. The required output power (rated burden) must be higher than the actually connected burden. Typical values are 5, 10, 15 VA. Higher values are normally not necessary when only electronic meters and recorders are connected. A typical specification could be: 0.5 M 10, 15 VA.

Protection cores: The size of the protection core depends mainly on the maximum short-circuit current and the total burden (internal c.t. burden, plus burden of connecting leads, plus relay burden). Further, an overdimensioning factor has to be considered to cover the influence of the d.c. component in the short-circuit current. In general, an accuracy of 1% (class 5 P) is specified. The accuracy limiting factor KALF should normally be designed so that at least the maximum short-circuit current can be transmitted without saturation (d.c. component not considered). This results, as a rule, in rated accuracy limiting factors of 10 or 20 dependent on the rated burden of the c.t. in relation to the connected burden. A typical specification for protection cores for distribution feeders is 5P10, 15 VA or 5P20, 10 VA. The requirements for protective current transformers for transient performance are specified in IEC 60044-6. The recommended calculation procedure for saturation-free design, however, leads to very high c.t. dimensions. In many practical cases, the c.t.s cannot be designed to avoid saturation under all circumstances because of cost and space reasons, particularly with metal-enclosed switchgear. The Siemens relays are therefore designed to tolerate c.t. saturation to a large extent. The numerical relays proposed in this guide are particularly stable in this case due to their integral saturation detection function.

RBC + Ri KALF > RBN + Ri

K*ALF

Iscc.max. IN

Iscc.max. = Maximum short-circuit current IN = Rated primary c.t. current KOF = Overdimensioning factor Fig. 6: C.t. dimensioning formulae

6/6

C.t. design according to BS 3938 In this case the c.t. is defined by the kneepoint voltage UKN and the internal secondary resistance Ri. The design values according to IEC 60 185 can be approximately transferred into the BS standard definition by the following formula:

UKN =

(RNC + Ri) • I2N • KALF 1.3

I2N = Nominal secondary current Example: IEC 185 : 600/1, 15 VA, 5P10, Ri = 4 Ohm (15 + 4) • 1 • 10 BS : UKN = = 146 V 1.3 Ri = 4 Ohm Fig. 7: BS c.t. definition

C.t. design according to ANSI/IEEE C 57.13 Class C of this standard defines the c.t. by its secondary terminal voltage at 20 times nominal current, for which the ratio error shall not exceed 10%. Standard classes are C100, C200, C400 and C800 for 5 A nominal secondary current. This terminal voltage can be approximately calculated from the IEC data as follows:

Vs.t. max = 20 x 5 A x RBN •

KALF : Rated c.t. accuracy limiting factor K*ALF : Effective c.t. accuracy limiting factor RBN : Rated burden resistance RBC : Connected burden Ri : Internal c.t. burden (resistance of the c.t. secondary winding) with: K*ALF > KOF

The required c.t. accuracy-limiting factor KALF can be determined by calculation, as shown in Fig. 6. The overdimensioning factor KOF depends on the type of relay and the primary d.c. time constant. For the normal case, with short-circuit time constants lower than 100 ms, the necessary value for K*ALF can be taken from the table in Fig. 9. The recommended values are based on extensive type tests.

KALF 20

with:

RBN = PBN and INsec = 5 A , we get INsec2 Vs.t. max =

PBN • KALF 5

Example: IEC 185 : 600/5, 25 VA, 5P20, 25 • 20 = ANSI C57.13: Vs.t. max = 5 = 100, i.e. class C100 Fig. 8: ANSI c.t. definition

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Protection and Substation Control Application Hints

Relay type o/c protection 7SJ511, 512, 551, 7SJ60, 61, 62, 63

Example: Stability-verification of the numerical busbar protection 7SS50

Minimum K*ALF

=

IHigh set point

1

Given case: , at least 20

IN

2 Transformer differential protection 7UT51

> – 50 for each side

Line differential (fiber-optic) protection 7SD511/512

=

Iscc. max. (external fault) IN

[K*ALF . IN](line-end 2)

3

Line differential (pilot wire) protection 7SD502/503/600

=

Numerical busbar protection (low impedance type) 7SS5

I = 1 scc. max. (outflowing current for ext. fault) IN 2

Distance protection 7SA511, 7SA513, 7SA522

= a

Iscc. max. (external fault) IN

600/1 5 P 10, 15 VA, Ri = 4 Ohm

[K*ALF . IN](line-end 1) and 1 <

1 2

6

50 = 25

a = 3 for 7SA511 a = 2 for 7SA513 and 7SA522

and

= 10

Iscc. max. (line-end fault)

=

15 VA = 15 Ohm; 1 A2

RRelay =

1.5 VA = 1.5 Ohm 1 A2

RBN

7

IN

8

Fig. 9: Required effective accuracy limiting factor K*ALF

Relay burden

Burden of the connection leads

The c.t. burdens of the numerical relays of Siemens are below 0.1 VA and can therefore be neglected for a practical estimation. Exceptions are the busbar protection 7SS50 (1.5 VA) and the pilot wire relays 7SD502, 7SD600 (4 VA) and 7SD503 (3 VA + 9 VA per 100 Ohm pilot wire resistance). Intermediate c.t.s are normally no longer applicable as the ratio adaption for busbar and transformer protection is numerically performed in the relay. Analog static relays in gereral also have burdens below about 1 VA. Mechanical relays, however, have a much higher burden, up to the order of 10 VA. This has to be considered when older relays are connected to the same c.t. circuit. In any case, the relevant relay manuals should always be consulted for the actual burden values.

The resistance of the current loop from the c.t. to the relay has to be considered:

Rl =

l

Rl

RBC

= Rl + RRelay = = 0.3 + 1.5

2 ρ l Ohm A

= single conductor length from the c.t. to the relay in m.

2 0.0179 50 = 0.3 Ohm 6

=

KALF

>

1.8 + 4 15 + 4

9

= 1.8 Ohm

10

25 = 7.6

Result: Specific resistance: Ohm mm2 ρ = 0.0179 (copper wires) m A = conductor cross section in mm2 Fig. 10

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

The rated KALF-factor (10) is higher than the calculated value (7.6). Therefore, the stability criterium is fulfilled. Fig. 11

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Power System Protection Introduction

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Introduction

SIPROTEC 3

Siemens is one of the world’s leading suppliers of protective equipment for power systems. Thousands of our relays ensure first-class performance in transmission and distribution networks on all voltage levels, all over the world, in countries of tropical heat or arctic frost. For many years, Siemens has also significantly influenced the development of protection technology. ■ In 1976, the first minicomputer (process computer)-based protection system was commissioned: A total of 10 systems for 110/20 kV substations were supplied and are still operating satisfactorily today. ■ Since 1985, we have been the first to manufacture a range of fully numerical relays with standardized communication interfaces. Today, Siemens offers a complete program of protective relays for all applications including numerical busbar protection. To date (1999), more than 150,000 numerical protection relays from Siemens are providing successful service, as standalone devices in traditional systems or as components of coordinated protection and substation control. Meanwhile, the innovative SIPROTEC 4 series has been launched, incorporating the many years of operational experience with thousands of relays, together with users’ requirements (power authority recommendations).

Fig. 12: Numerical relay ranges of Siemens

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SIPROTEC 4

State of the art Mechanical and solid-state (static) relays have been almost completely phased out of our production because numerical relays are now preferred by the users due to their decisive advantages: ■ Compact design and lower cost due to integration of many functions into one relay ■ High availability even with less maintenance due to integral self-monitoring ■ No drift (aging) of measuring characteristics due to fully numerical processing ■ High measuring accuracy due to digital filtering and optimized measuring algorithms ■ Many integrated add-on functions, for example, for load-monitoring and event/fault recording ■ Local operation keypad and display designed to modern ergonomic criteria ■ Easy and secure read-out of information via serial interfaces with a PC, locally or remotely ■ Possibility to communicate with higherlevel control systems using standardized protocols (open communication)

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Power System Protection Introduction

1

52

21

67N

FL

79

25

SM

ER

FR

BM

2

85

3

Serial link to station – or personal computer to remote line end

21 67N FL 79 25 85 SM ER FR BM

Distance protection Directional ground-fault protection Distance-to-fault locator Autoreclosure Synchro-check Carrier interface (teleprotection) Self-monitoring Event recording Fault recording Breaker monitor

kA, kV, Hz, MW, MVAr, Load monitor MVA,

01.10.93

4

Fault report Fault record

5

Relay monitor Breaker monitor Supervisory control

6

Fig. 13: Numerical relays, increased information availability

Modern protection management All the functions, for example, of a line protection scheme can be incorporated in one unit: ■ Distance protection with associated add-on and monitoring functions ■ Universal teleprotection interface ■ Autoreclose and synchronism check Protection-related information can be called up on-line or off-line, such as: ■ Distance to fault ■ Fault currents and voltages ■ Relay operation data (fault detector pickup, operating times etc.) ■ Set values ■ Line load data (kV, A, MW, kVAr) To fulfill vital protection redundancy requirements, only those functions which are interdependent and directly associated with each other are integrated in the same unit. For back-up protection, one or more additional units have to be provided.

All relays can stand fully alone. Thus, the traditional protection concept of separate main and alternate protection as well as the external connection to the switchyard remain unchanged. ”One feeder, one relay“ concept Analog protection schemes have been engineered and assembled from individual relays. Interwiring between these relays and scheme testing has been carried out manually in the workshop. Data sharing now allows for the integration of several protection and protection related tasks into one single numerical relay. Only a few external devices may be required for completion of the total scheme. This has significantly lowered the costs of engineering, assembly, panel wiring, testing and commissioning. Scheme failure probability has also been lowered. Engineering has moved from schematic diagrams towards a parameter definition procedure. The documentation is provided by the relay itself. Free allocation of LED operation indicators and output contacts provides more application design flexibility.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

7

Measuring included For many applications, the protective-current transformer accuracy is sufficient for operational measuring. The additional measuring c.t. was more for protection of measuring instruments under system fault conditions. Due to the low thermal withstand ability of the measuring instruments, they could not be connected to the protection c.t.. Consequently, additional measuring c.t.s and measuring instruments are now only necessary where high accuracy is required, e.g. for revenue metering.

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Power System Protection Introduction

On-line remote data exchange

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2

3

A powerful serial data link provides for interrogation of digitized measured values and other information stored in the protection units, for printout and further processing at the substation or system control level. In the opposite direction, settings may be altered or test routines initiated from a remote control center. For greater distances, especially in outdoor switchyards, fiber-optic cables are preferably used. This technique has the advantage that it is totally unaffected by electromagnetic interference.

Recording

Personal computer DIGSI

Assigning

Protection

Laptop

DIGSI

Off-line dialog with numerical relays

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10

A simple built-in operator panel which requires no special software knowledge or codeword tables is used for parameter input and readout. This allows operator dialog with the protection relay. Answers appear largely in plaintext on the display of the operator panel. Dialog is divided into three main phases: ■ Input, alternation and readout of settings ■ Testing the functions of the protection device and ■ Readout of relay operation data for the three last system faults and the autoreclose counter.

Recording and confirmation

Fig. 14: PC-aided setting procedure

Substation level

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Coordinated protection & control

Modem (option)

Modern system protection management A more versatile notebook PC may be used for upgraded protection management. The MS Windows-compatible relay operation program DIGSI is available for entering and readout of setpoints and archiving of protection data. The relays may be set in 2 steps. First, all relay settings are prepared in the office with the aid of a local PC and stored on a floppy or the hard disk. At site, the settings can then be downloaded from a PC into the relay. The relay confirms the settings and thus provides an unquestionable record. Vice versa, after a system fault, the relay memory can be uploaded to a PC, and comprehensive fault analysis can then take place in the engineer’s office. Alternatively, the total relay dialog can be guided from any remote location through a modem-telephone connection (Fig. 15).

to remote control

System level

ERTU

RTU

Data concentrator

Bay level 52 Relay

Control

Fig. 15: Communication options

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Power System Protection Introduction

Relay data management Analog-distribution-type relays have some 20–30 setpoints. If we consider a power system with about 500 relays, then the number adds up to 10,000 settings. This requires considerable expenditure in setting the relays and filing retrieval setpoints. A personal computer-aided man-machine dialog and archiving program, e.g. DIGSI, assists the relay engineer in data filing and retrieval. The program files all settings systematically in substation-feeder-relay order. Corrective rather than preventive maintenance Numerical relays monitor their own hardware and software. Exhaustive self-monitoring and failure diagnostic routines are not restricted to the protective relay itself, but are methodically carried through from current transformer circuits to tripping relay coils. Equipment failures and faults in the c.t. circuits are immediately reported and the protective relay blocked. Thus, the service personnel are now able to correct the failure upon occurrence, resulting in a significantly upgraded availability of the protection system.

Setpoints

200 setpoints

20 setpoints

1200 flags p. a.

10 000 setpoints 1 system approx. 500 relays

300 faults p. a. approx. 6,000 km OHL (fault rate: 5 p. a. and 100 km)

2

system

3

1 sub

4 flags

4

1 bay

bay OH-Line

5

Fig. 16: System-wide setting and relay operation library

6 1000 1000

Adaptive relaying Numerical relays now offer secure, convenient and comprehensive matching to changing conditions. Matching may be initiated either by the relay’s own intelligence or from the outside world via contacts or serial telegrams. Modern numerical relays contain a number of parameter sets that can be pretested during commissioning of the scheme (Fig. 17). One set is normally operative. Transfer to the other sets can be controlled via binary inputs or serial data link. There are a number of applications for which multiple setting groups can upgrade the scheme performance, e.g. a) for use as a voltage-dependent control of o/c relay pickup values to overcome alternator fault current decrement to below normal load current when the AVR is not in automatic operation. b) for maintaining short operation times with lower fault currents, e.g. automatic change of settings if one supply transformer is taken out of service. c) for “switch-onto-fault” protection to provide shorter time settings when energizing a circuit after maintenance. The normal settings can be restored automatically after a time delay.

1

Relay operations

1000

Parameter

1100 ParameterLine data

D

C

1100 Line data O/C Phase settings 1200 Parameter

1000 1100

Line data O/C Phase settings 1200 1500 O/C EarthFault settings 2800 Recording O/C PhaseO/C settings 1500 settings 2800 Earth Fault Recording 3900 Breaker Fall O/C Ground settings 2800 Fault Recording 3900 Breaker Fall

1200 1500 2800 3900

7

B

1100 Line data O/C Phase settings 1200 Parameter 1500 O/C Earth settings

A

8

Fault recording 3900 Breaker Fall

9

Breaker fail

10 Fig. 17: Alternate parameter groups

d) for autoreclose programs, i.e. instantaneous operation for first trip and delayed operation after unsuccessful reclosure. e) for cold load pick-up problems where high starting currents may cause relay operation. f) for ”ring open“ or ”ring closed“ operation.

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

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Power System Protection Relay Design and Operation

Mode of operation

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6

7

8

9

10

Numerical protection relays operate on the basis of numerical measuring principles. The analog measured values of current and voltage are decoupled galvanically from the plant secondary circuits via input transducers (Fig. 18). After analog filtering, the sampling and the analog-to-digital conversion take place. The sampling rate is, depending on the different protection principles, between 12 and 20 samples per period. With certain devices (e.g. generator protection) a continuous adjustment of the sampling rate takes place depending on the actual system frequency. The protection principle is based on a cyclic calculation algorithm, utilizing the sampled current and voltage analog measured values. The fault detections determined by this process must be established in several sequential calculations before protection reactions can follow. A trip command is transferred to the command relay by the processor, utilizing a dual channel control. The numerical protection concept offers a variety of advantages, especially with regard to higher security, reliability and user friendliness, such as: ■ High measurement accuracy: The high ultilization of adaptive algorithms produce accurate results even during problematic conditions ■ Good long-term stability: Due to the digital mode of operation, drift phenomena at components due to ageing do not lead to changes in accuracy of measurement or time delays ■ Security against over and underfunction With this concept, the danger of an undetected error in the device causing protection failure in the event of a network fault is clearly reduced when compared to conventional protection technology. Cyclical and preventive maintenance services have therefore become largely obsolete. The integrated self-monitoring system (Fig. 19) encompasses the following areas: – Analog inputs – Microprocessor system – Command relays.

PC interface LSA interface

Meas. inputs

Input filter

Current inputs (100 x /N, 1 s)

Amplifier

Input/ output ports

V.24 FO Serial Interfaces

Binary inputs

Alarm relay

Command relay Voltage inputs (140 V continuous)

100 V/1 A, 5 A analog

A/D converter

Processor system

0001 0101 0011

10 V analog

Memory: RAM EEPROM EPROM

digital

Input/ output units

LED displays

Input/output contacts

Fig. 18: Block diagram of numerical protection

Plausibility check of input quantities e.g. iL1 + iL2 + iL3 = iE uL1 + uL2 + uL3 = uE

Check of analog-to-digital conversion by comparison with converted reference quantities

A D

Microprocessor system

Hardware and software monitoring of the microprocessor system incl. memory, e.g. by watchdog and cyclic memory checks

Relay

Monitoring of the tripping relays operated via dual channels Tripping check or test reclosure by local or remote operation (not automatic)

Fig. 19: Self-monitoring system

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Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

Power System Protection Relay Design and Operation

Implemented Functions SIOPROTEC relays are available with a variety of protective functions. See relay charts (page 6/20 and following). The high processing power of modern numerical devices allow further integration of non-protective add-on functions.

1

2

The question as to whether separate or combined relays should be used for protection and control cannot be uniformly answered. In transmission type substations, separation into independent hardware units is still preferred, whereas on the distribution level a trend towards higher function integration can be observed. Here, combined feeder relays for protection, monitoring and control are on the march (Fig. 20).

3

4

Most of the relays of this guide are standalone protection relays. The exception in the SIPROTEC 3 series is the distribution feeder relay 7SJ531 that also integrates control functions. Per feeder, only one relay package ist needed in this case leading to a considerable reduction in space und wiring.

5

With the new SIPROTEC 4 series (types 7SJ61, 62 and 63), Siemens supports both stand-alone and combined solutions on the basis of a single hardware and software platform. The user can decide within wide limits on the configuration of the control and protection functions in the feeder, without compromising the reliability of the protection functions (Fig. 21).

Fig. 20: Switchgear with numerical relay (7SJ62) and traditional control

Switchgear with combined protection and control relay (7SJ63)

The following solutions are available within one relay family: ■ Separate control and protection relays ■ Protection relays including remote control of the feeder breaker via the serial communication link

■ Combined feeder relays for protection,

monitoring and control Mixed use of the different relay types is readily possible on account of the uniform operation and communication procedures.

7

7SJ61/ 62/63

Busbar

7SJ62/63

52 Local/Remote control Commands/Feedback indications Motor control (only 7SJ63) HMI

50

51

Trip circuit supervision

PLC logic

Vf (option) Fault locator

Lockout

74TC

6

&

86

59

Rotating field monitoring

27

47 Fault recording

Communications module RS23/485 fiber optic IEC 60 870-5-103 PROFIBUS FMS

50N 51N 46

810/U

21FL

8

Directional (option)

Metering values I2 limit values Metered power values pulses

49

Auto reclosing

Inrush restrain

79M

60N 51N

Calculated

10

Motor protection (option) Starting time

50BF Breaker failure protection

37

48

14 Locked rotor

9

V, Watts, Vars f.p.f.

66/86 Start inhibit

67

67N

Directional groundfault detection (option)

67

64

Fig. 21: SIPROTEC 4 relays 7SJ61/62/63, implemented function

Siemens Power Engineering Guide · Transmission and Distribution · 4th Edition

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Power System Protection Relay Design and Operation

1

2

3

4

5

6

Integration of relays in the substation automation Basically, Siemens numerical relays are all equipped with an interface to IEC 60870-5-103 for open communication with substation control systems either from Siemens (SINAUT LSA or SICAM, see page 6/71 ff) or of any other supplier. The relays of the newer SIPROTEC 4 series, however, are even more flexible and equipped with communication options. SIPROTEC 4 relays may also be connected to the SINAUT LSA system or to a system of another supplier via IEC 60870-5-103. But, SICAM 4 relays were originally designed as components of the new SICAM substation automation system, and their common use offers the most technical and cost benefits. SIPROTEC 4 protection and SICAM station control, which is based on SIMATIC, are of uniform design, and communication is based on the Profibus standard. SIPROTEC 4 relays can in this case be connected to the Profibus substation LAN of the SICAM system via one serial interface. Through a second serial interface, e.g. IEC 60 870-5-103, the relay can separately communicate with a remote PC via a modem-telephone line (Fig. 22).

DIGSI 4

DIGSI 4 Telephone connection

SICAM SAS

PROFIBUS FMS Modem

IEC 60870-5-103 DIGSI 4

IEC 60870-5-103

Fig. 22: SIPROTEC 4 relays, communication options

1

1 2

2

3

3

4

4 5

6 7

6

Local relay operation

7

8

9

10

All operator actions can be executed and information displayed on an integrated user interface. Many advantages are already to be found on the clear and user-friendly front panel: ■ Positioning and grouping of the keys supports the natural operating process (ergonomic design) ■ Large non-reflective back-lit display ■ Programmable (freely assignable) LEDs for important messages ■ Arrows arrangement of the keys for easy navigation in the function tree ■ Operator-friendly input of the setting values via the numeric keys or with a PC by using the operating program DIGSI 4 ■ Command input protected by key lock (6MD63/7SJ63 only) or password ■ Four programmable keys for frequently used functions >at the press of a button