29 0 2MB
1
ALTERNATOR RANGE Brushless 5KVA To 1010KVA,1500rpm,3-Ph,415Volt Brushless 5KVA To 50KVA,1500rpm,1-Ph,240Volt Brushless 5KVA To 30KVA, 3000rpm,3-Ph,415Volt Brushless 5KVA To 15KVA,3000rpm,1-Ph,240-Volt
2
AL. BODY ALTERNATOR ( 160 FR: 15 - 30KVA)
3
AL. BODYALTERNATOR(200 FR: 35 -90kVA)
4
AL.BODY ALTERNATOR(250 FR: 100-200kVA )
5
FAB. BODY ALTERNATOR(315/355&400FR:250-1010kVA)
6
WHAT IS ALTERNATOR..? Alternator or AC Generator is a Electrical Rotating M/c, which converts Mechanical INPUT power into Electrical output Power.
TYPES OF ATERNATOR 1. Brush less Alternator :- As the name indicates there is no slip ring & brushes for feeding the the DC power to Field winding. 2. Slip-ring Alternator :- There is slip ring & brushes for feeding the the DC power to Field winding. 7
SALIENT FEATURES OF CGL ALTERNATORS
Al. alloy gravity die cast stator body - Pleasing look & light in weight.
2/3 rd pitch windings : Offers better suitability for Non-linear loads.
Efficiencies - Better/ at par with competitors.
Spacious Terminal box with provision of double side entry – Flexibility & Ease of Al. customer cables termination inside the box.
Out-board Diode board assembly (as against inboard in case of competitors)- Ease of service.
Epoxy gel treatment on Winding overhangs : Offers better suitability for tropical environment.
Life long lubricated sealed bearings.
8
DECODING OF MACHINES AND EXCISE REF. NO.
9
STD./OPTIONAL TECHNICAL SPECN
10
OPERATION PRINCIPLE OF BRUSHLESS ALTERNATOR
11
FEW COMPONENTS
12
Exciter Rotor & Main Rectifier Assembly Exciter Rotor 3 Phase with Internal Star Point
SHAFT
13
Exciter Rotor & Main Rectifier Assembly Exciter Rotor with Internal Star Point
Rectifier Assembly
To Main Rotor
14
Main Rectifier Assembly- Operation of a Diode +VE ✲ A.C Input to Rectifier Diodes ✲ Rectifier Diode Positive Heatsink Cathode Stud
+
0 -VE +VE 0 -VE
✲ Rectifier Diode Negative Heatsink Anode Stud
+VE 0 -VE
15
Main Rectifier Assembly- 3 Phase Rectification ✲ A.C Input to Rectifier Diodes
+
✲ D.C output to Main Rotor
✲ Full wave 3 Phase rectification will produce a D.C output
16
Metal Oxide Varistor (Surge Suppressor)
Diode Protection Device For Transient Suppression
SHAFT
Main Rotor Connections
17
Main Rectifier Connections to Main Rotor
Main Rectifier ✲ Aluminium bus bar
SHAFT
Main Rotor
D.C
✲ The Rectifier Output is a smooth D.C Supply across the Aluminium bus bars ✲ This is fed to the Main Rotor windings
18
What does “BRUSHLESS BRUSHLESS” BRUSHLESS Generator mean? D.C. FIELD POLES
OUTPUT
CARBON BRUSHES
A.C.ARMATURE
SHAFT
SLIPRINGS BEARINGS
✲ Long back CG Generators were designed with SLIPRINGS and CARBON BRUSHES, to transfer power from the rotating component of the Generator. ✲ These had a tendency to wear out, spark, burn, with vibration or high transient load currents. ✲ ‘BRUSHLESS’ Generators are designed to allow output to be taken from the Generator WITHOUT SLIP-RINGS AND BRUSHES.
NOW LET’S LOOK AT A BRUSHLESS GENERATOR !! 19
Double Bearing Main Rotor Assembly Main Rotor Exciter Rotor
Fan
Bearings
Rectifier
Bearings are sealed for life. Rotating rectifier assly is fitted to the non drive end of the Exciter rotor
20
Single Bearing Main Rotor Assembly Main Rotor Exciter Rotor
Fan
Bearing
Rectifier
✲ Drive End of Generator Shaft is supported by the Engine Flywheel ✲Sealed bearing for life time
21
Wound Main Stator Assembly ✲ ✲ ✲ ✲ ✲ ✲
Core built from high grade Electrical Steel, to reduce Iron losses (heat). Each lamination is electrically insulated to minimise Eddy Currents in the core. 12 Ends Out Re-connectable, 6 Ends out Star / Delta, or Dedicated Windings. Class ‘H’ Insulation as standard, 125 º C Temperature rise in 40º Ambient. 2/3rds Pitch windings, Multiple of 3 ( 3rd, 6th, 9th ect.), Harmonics are eliminated. VPI Impregnation with Class H resin as standard.
Laminated Steel core
Copper Windings
Output Leads
22
Wound Main Rotor - Coil Group connections ANTI CLOCK
D.C Input From Main Rectifier
S CLOCK
N
N
CLOCK
S ANTI CLOCK
✲ The Rotor coils are connected in Series (4 Pole Rotor shown). ✲ Each coil is reversed to the adjacent coil, producing the required polarity
23
Wound Main Rotor - Poles & Frequency Generator Frequency (HZ) = Speed (N) X Pairs of poles (P) 60
2 Pole
4 Pole
SHAFT
S
N N
N
S
SHAFT
S
24
Main Rotor- Damper Windings
SHAFT
✲Damper Bars ✲Aluminium Damper Bars Welded to End Plates
N
N
S
S
25
Main Rotor- Amortisseur (Damper) Windings
SHAFT
N
N
S
S ✲ Helps dampen speed oscillations resulting from cyclic irregularities in the engine, (cause of ‘light flicker’). ✲ Stabilises the mechanical systems during large load changes. ✲ Stabilises load sharing with other Generators in Parallel. ✲ Improves Harmonic Distortion in the Generator waveform
26
Excitation System - Exciter Stator Exciter Stator
Main Stator Exciter Rotor & Stator Bearing
Main Rotor
Shaft
Rectifier Fan
27
Excitation System - Wound Exciter Stator X+ (F1) XX- (F2)
To A.V.R Terminals
COIL CONNECTIONS
N
S
N
S
✲ High-remanence steel core ✲ Stores Residual Magnetism ✲ High frequency Generator FOR 132/160/200 FRAME = 6 POLES FOR 250/280 FRAME = 6 POLES FOR 315 / 355 FRAME = 12 POLES
28
AL Series Double Bearing Alternator Terminal Block
Covers
AVR Main Stator Assembly
V1 W1 U1 V1
Main Rotor Assembly Exciter Rotor Laminated Steel core With RRA
Exciter Stator
29
AL Series Single Bearing Alternator Assembled Alternator with Single Bearing Rotor
Coupling Disc / Flex Plate
Disc Tightening Bolts
30
EXCITATION SYSTEM
31
32
33
AVR SR-7/3(5 TO 40KVA) &7/6 (45 TO 200 KVA) SPECIAL FEATURES
SR-7/3
SR-7/6
SR-7/3-1-ph
34
UVR7 (180 to 1010 KVA) SPECIAL FEATURES
35
UVR7 (180 to 1010 KVA)SPECIAL FEATURES
36
AVR-SPECIFICATIONS
37
DO’s & DON’T’s
38
DO’S
ENSURE RATED VOLTAGE ON NO-LOAD AT 52 Hz (ENGINE SPEED FOR 1560 RPM) ENSURE THAT ENGINE SPEED IS NEVER BELOW 50 Hz.(1500 RPM) FROM NO-LOAD TO FULL LOAD. ENSURE THAT ALTERNATOR NEUTRAL IS EARTHED PROPERLY ENSURE THAT ALL CONNECTIONS & FOOT FIXING HOLE ARE TIGHTNED PROPERLY TO AVOID VIBRATIONS. ENSURE PROPER AIR CIRCULATION INSIDE THE DG-SET ROOM SO THAT AMBIENT TEMP. IS NOT MORE THAN 40 ‘C . ENSURE THAT MEGGER VALUE OF THE WINDING IS MORE THAN 2MEG-OHMS. (REMOVE ALL THE CONNECTIONS
39
DONT’S DONOT DISTURB AVR POTENTIOMETER SETTING EXCEPT VOLT. POTENTIOMETER DONOT CHARGE THE ALTERNATOR WHEN AVR IS IN CONNECTED CONDITION & ALTERNATOR IS RUNNING DO NOT OVER LOAD THE ALTERNATOR . DO NOT OPERATE THE ALTERNATOR ON LESS THAN 0.8 LAG PF DO NOT OPERATE ON LEADING POWER FACTOR (CAPACITOR LOAD) DO NOT MEGGER/HV TEST WINDINGS BEFORE REMOVING THE CONNECTIONS TO AVR DO NOT OPERATE ON LESS THAN 1500 RPM. (50 Hz)
40
1-BRG.SET.ASLY CHECK POINTS DO NOT APPLY ANY FORCE TO THE ALTERNATOR FAN. DO NOT REMOVE ANY COUPLING DISC FROM THE SET. ENSURE “WA” DIMN. AN ENGINE & ALTERNATOR (i.e The dist. from coupling disc face to alternator Flange spigot face. It should be within 0.5mm) USE ONLY 8.8 CL. SCREWS & HARDEDNED WASHERS DO NOT USE SPRING WASHERS ON COUPLING DISC DISC SCREWS TO BE TIGHTEND WITH SPECIFIED TORQUE AS BELOW M10-6 kg-m ,
M12 –10 kg-m ,
M16- 24 kg-m , M20- 48 kg-m
41
COMMISIONING & INSTALLATION CHECK POINTS POINT OF OBSERVATION
CHECK POINTS
VISUAL OBSERVATION
ENSURE PROPER EARTHING
Check the voltage on No-load volts
NO-LOAD ELECTRICAL PARAMETERS
No-load freq For brushless 51.5 to 52 hz For capacitor type 50-51 hz No-load voltage For 1-phase 230 or 240 as per N/p For 3-ph 415v Voltage variation Should be less than 1volt on digital voltmeter having 1digit accuracy
ON LOAD PARAMETERS
Voltage to be measured Load current to be seen (it should be well within the n/p data) Freq should not go down below 50hz
GENERAL OBSERVATIONS
Vibration normal or abnormal If any abnormality in sound
Proper tightening of all screws including base frame There should be no loose connection b/w body and neutral-it should be less than 3
42
TROUBLE SHOOTING
43
VOLTAGE FAULTS FAULT No voltage built-up
CAUSE 1.Insufficient residual voltage 2. Improper connection 3. Low speed 4. Faulty Winding 5.Rotating rectifier failure 6. Faulty AVR
Low no-load voltage
1. Low speed 2. Faulty Rotating rectifier 3. Faulty Winding
REPAIR 1.Excite the exc.stator using a battery 2. Correct the connection 3. Reset the speed to the nominal 4. Check the wdg. Resistance Rewind if required 5. Replace the rotating rectifier 6. Replace the AVR 1. Reset the speed to the nominal 2. Replace the Rotating rectifier 3. Check the wdg. Resistance Rewind if required
44
FAULT
CAUSE
REPAIR
Voltage Oscillations
1. In correct AVR setting 2. Thyristor load more than specified limits
1. Set the AVR stability pot 2. Reduce the Tghyristor load
Unbalance voltage
1. Unbalance Load 2. Loose connections 3. Stator winding faulty
1. Correct the load 2. Tightend the loose connections 3. Check the wdg. Resistance Rewind if required
45
FAULT Low voltage on load
CAUSE 1. Low speed at full load. 2. Faulty rotor Winding 3. Over load on Alternator
REPAIR 1. Set the rated speed of the Engine 2. Check the wdg. Resistance Rewind if required 3. Operate on specified load.
High voltage on load
1. Capacitor on the load side
1. Disconnect the PF improvement capacitor
Too high No-load voltage
1. Excessive speed
1. Adjust the speed
46
HOW TO SELECT ALTERNATOR RATING
47
DERATING FACTORS DERATION FOR AMB. TEMP. DERATING FACTOR
1.05 1 0.95 0.9 0.85 0.8 0.75
D.Factor
40
45
50
55
60
1
0.96
0.92
0.88
0.84
AMB. TEMP
No deration upto Std. Amb : 40°c .
48
DERATING FACTORS
CONTD…..
DERATION FOR ALTITUDE. DERATING FACTOR
1.2 1 0.8 0.6 0.4 0.2 0
D.Factor
1000
1500
2000
2500
3000
3500
1
0.96
0.92
0.88
0.84
0.8
ALTITUDE
No deration upto Std. Altitude level : 1000 M . 49
DERATING FACTORS
CONTD…..
DERATION FOR POWER FACTOR( LAG) DERATING FACTOR
1.05 1 0.95 0.9 0.85 0.8 0.75
D.Factor
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
1
0.95
0.91
0.88
0.86
0.85
0.84
0.84
0.84
POWER FACTOR
No deration for UPF to 0.8 Pf 50
SELECTION OF ALT. FOR VARIOUS LOADS
LINEAR LOAD
Includes Resistance,Inductance & Capacitance.
Estimate connected load in KW & operating power factor
Our alternators are suitable for 0.8 lag to Unity pf.
51
SELECTION OF ALT. FOR VARIOUS LOADSCONTD….. UNBALANCE LOAD
Maximum unbalance allowed is 25% I.e.( ( I Max – I Min ) / I Max ) * 100 = 25%
Any phase current should not exceed rated current
WELDING LOAD
3 phase welding load should be < 50% KVA rating
1 phase welding load should be < 33% KVA rating
52
SELECTION OF ALT. FOR VARIOUS LOADS INDUCTION MOTOR LOAD
Capable of starting 1HP with 1 kVA (upto 10kVA)
Capable of delivering 3.5 times of rated current for 10 Sec.
THYRISTOR LOAD
Generates harmonics which is harmful to alternator,so required derating.
Alternator KVA rating = 1.5 X + Y Where X is thyristor load & Y is linear load. 53
WHY ?… DERATING REQUIRED FOR NON-LINEAR LOADS Due to excess heating because of:
High Hysterisis loss.
High Eddy-Current loss.
Skin effect in armature winding.
NOTE:- NO STANDARD IS AVALIABLE FOR DERATING,
54
GUIDELINES FOR NON-LINEAR LOADS LOAD
GUIDELINES
FLOURESCENT LIGHTING LOAD
No derating required.
UPS & TELECOM LOAD CONTROLLED BY A TWELVE PULSE THYRISTOR BRIDGE PLUS A FILTER
Non linear load should not exceed 90% of the alternator rating
UPS & TELECOM LOAD CONTROLLED BY A SIX PULSE THYRISTOR BRIDGE PLUS A FILTER
Non linear load should not exceed 66% of the alternator rating
UPS & TELECOM LOAD CONTROLLED BY A THREE PULSE THYRISTOR BRIDGE PLUS A FILTER
Non linear load should not exceed 35% of the alternator rating
VARIABLE SPEED 6 PULSE THYRISTOR BRIDGE CONTROL DRIVE.
Non linear load should not exceed 50% of the alternator rating
55
REMEDIES FOR NON-LINEAR LOAD
Oversize of the neutral conductor (200% of the phase conductor).
Location of isolation transformer close to the load.
Derating of Alternator & Transformer.
Use of true RMS sensing meters & relay.
Select power source with low o/p Impendence.
Provide line filters.
56
REMEDIES FOR NON-LINEAR LOAD
Oversize of the neutral conductor (200% of the phase conductor).
Location of isolation transformer close to the load.
Derating of Alternator & Transformer.
Use of true RMS sensing meters & relay.
Select power source with low o/p Impendence.
Provide line filters.
57
RELATION B/T STARTING METHOD & STARTING CURRENT METHOD OF STARTING
STARTING CURRENT
DIRECT ON-LINE STARTING (DOL)
6-7 times of the rated full load current ( If starting current is not given than starting KVA is 7 times HP rating)
STAR/DELTA STARTING
2-2.5 times of the full load current
ROTOR RESISTANCE
1.5-2 times the full load current
AUTO TRANSFORMER STARTING 40% Tapping 60% Tapping 80% Tapping
1.2 times the full load current 4.0 times the full load current 4.5 times the full load current
58
HOW TO SELECT AN ALTERNATOR…? STEPS
Estimate total KW say-’’X’’
Estimate total power factor say-’’Y’’
Provide 10-15% allowance Alternator KVA rating = ( X/Y ) * 1.15 For Non-linear load contact manufacturer
59
HOW TO SELECT ENGINE RATING…..?
ENGINE HP IS GIVEN BY:-
(KVA * PF) /( 0.735 * Efficiency of alternator)
60
Thank you
61