Brushless ALTERNATOR Customer Training

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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

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AL. BODY ALTERNATOR ( 160 FR: 15 - 30KVA)

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AL. BODYALTERNATOR(200 FR: 35 -90kVA)

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AL.BODY ALTERNATOR(250 FR: 100-200kVA )

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FAB. BODY ALTERNATOR(315/355&400FR:250-1010kVA)

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WHAT IS ALTERNATOR..?

Alternator or AC Generator is a Electrical Rotating M/c,which converts Mechanical INPUT power into Electricaloutput Power.

TYPES OF ATERNATOR

1. Brush less Alternator :- As the name indicatesthere is no slip ring & brushes for feeding the theDC power to Field winding.

2. Slip-ring Alternator :- There is slip ring &brushes for feeding the the DC power to Fieldwinding.

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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 ofcompetitors)- Ease of service.

Epoxy gel treatment on Winding overhangs : Offers better suitability fortropical environment.

Life long lubricated sealed bearings.

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DECODING OF MACHINES ANDEXCISE REF. NO.

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STD./OPTIONAL TECHNICAL SPECN

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OPERATION PRINCIPLE OFBRUSHLESS ALTERNATOR

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FEW COMPONENTS

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SHAFT

Exciter Rotor & Main Rectifier Assembly

Exciter Rotor 3 Phase

with Internal Star Point

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Exciter Rotor & Main Rectifier Assembly

To Main Rotor

Exciter Rotor with Internal Star Point

Rectifier Assembly

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+VE

0

-VE

Main Rectifier Assembly- Operation of a Diode

R Rectifier Diode

Positive Heatsink

Cathode Stud

R Rectifier Diode

Negative Heatsink

Anode Stud

+VE

0

-VE

+VE

0

-VE

R A.C Input to Rectifier Diodes

+

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Main Rectifier Assembly- 3 Phase Rectification

R Full wave 3 Phase rectification will produce a D.C output

R A.C Input to Rectifier Diodes

R D.C output to Main Rotor+

-

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Metal Oxide Varistor (Surge Suppressor)

Diode Protection Device

For Transient Suppression

Main Rotor

ConnectionsSHAFT

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SHAFT

Main Rectifier Connections to Main Rotor

D.C

Main Rotor

R The Rectifier Output is a smooth D.C Supply across the Aluminium bus bars

R This is fed to the Main Rotor windings

Main RectifierR Aluminium

bus bar

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What does What does What does What does BRUSHLESSBRUSHLESSBRUSHLESSBRUSHLESS Generator mean? Generator mean? Generator mean? Generator mean?

R Long back CG Generators were designed with SLIPRINGS and CARBON BRUSHES, totransfer power from the rotating component of the Generator.

R BRUSHLESS Generators are designed to allow output to be taken from the GeneratorWITHOUT SLIP-RINGS AND BRUSHES.

R These had a tendency to wear out, spark, burn, with vibration or high transient loadcurrents.

SLIPRINGS

CARBONBRUSHES

BEARINGS

NOW LETS LOOK AT A BRUSHLESS GENERATOR !!

OUTPUT

SHAFTA.C.ARMATURE

D.C. FIELD POLES

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Bearings are sealed for life. Rotating rectifier assly is fitted to the non drive end of the Exciter rotor

Double Bearing Main Rotor Assembly

FanMain Rotor

BearingsExciter Rotor

Rectifier

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Single Bearing Main Rotor Assembly

R Drive End of Generator Shaft is supported by the Engine FlywheelRSealed bearing for life time

Main Rotor Fan

Rectifier

Exciter

Rotor Bearing

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Wound Main Stator Assembly

R Core built from high grade Electrical Steel, to reduce Iron losses (heat).

R Each lamination is electrically insulated to minimise Eddy Currents in the core.

R 12 Ends Out Re-connectable, 6 Ends out Star / Delta, or Dedicated Windings.

R Class H Insulation as standard, 125 C Temperature rise in 40 Ambient.

R 2/3rds Pitch windings, Multiple of 3 ( 3rd, 6th, 9th ect.), Harmonics are eliminated.

R VPI Impregnation with Class H resin as standard.

Laminated Steel core Copper Windings

Output Leads

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Wound Main Rotor - Coil Group connections

S

S

N N

D.C InputFrom Main

Rectifier

R The Rotor coils are connected in Series (4 Pole Rotor shown).

R Each coil is reversed to the adjacent coil, producing the required polarity

ANTI CLOCK

ANTI CLOCK

CLOCK CLOCK

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S

N NS

SHAFT

4 Pole 2 Pole

Generator Frequency (HZ) = Speed (N) X Pairs of poles (P)

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S

SHAFT

N

Wound Main Rotor - Poles & Frequency

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S

N N

S

SHAFT

RDamper Bars RAluminium Damper Bars Welded to End Plates

Main Rotor- Damper Windings

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R Stabilises the mechanical systems during large load changes.

R Stabilises load sharing with other Generators in Parallel.

R Improves Harmonic Distortion in the Generator waveform

R Helps dampen speed oscillations resulting from cyclic irregularities in

the engine, (cause of light flicker).

Main Rotor- Amortisseur (Damper) Windings

SN N

S

SHAFT

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Exciter

Stator

Excitation System - Exciter Stator

Exciter

Rotor

& Stator

Main Stator

Bearing

Shaft

RectifierFan

Main Rotor

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R High-remanence steel coreR Stores Residual Magnetism

R High frequency Generator

To A.V.R TerminalsXX- (F2)

X+ (F1)

Excitation System - Wound Exciter Stator

N S N S

COIL CONNECTIONS

FOR 132/160/200 FRAME = 6 POLES

FOR 250/280 FRAME = 6 POLES

FOR 315 / 355 FRAME = 12 POLES

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AL Series Double Bearing Alternator

V1V1 W1U1

Laminated Steel core

Main RotorAssembly

Main StatorAssembly

CoversTerminal

BlockAVR

Exciter Rotor With RRA

Exciter Stator

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AL Series Single Bearing Alternator

Assembled Alternator with Single Bearing Rotor

Coupling Disc / Flex Plate

Disc Tightening Bolts

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EXCITATION SYSTEM

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AVR SR-7/3(5 TO 40KVA) &7/6 (45 TO 200 KVA) SPECIALFEATURES

SR-7/6SR-7/3

SR-7/3-1-ph

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UVR7 (180 to 1010 KVA)SPECIAL FEATURES

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UVR7 (180 to 1010 KVA)SPECIAL FEATURES

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AVR-SPECIFICATIONS

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DOs & DONTs

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DOS

ENSURE RATED VOLTAGE ON NO-LOAD AT 52 Hz (ENGINE SPEEDFOR 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 ARETIGHTNED PROPERLY TO AVOID VIBRATIONS.

ENSURE PROPER AIR CIRCULATION INSIDE THE DG-SET ROOM SOTHAT AMBIENT TEMP. IS NOT MORE THAN 40 C .

ENSURE THAT MEGGER VALUE OF THE WINDING IS MORE THAN 2-MEG-OHMS. (REMOVE ALL THE CONNECTIONS

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DONTS

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)

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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

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COMMISIONING & INSTALLATION CHECK POINTS

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

ON LOAD PARAMETERS

Vibration normal or abnormal

If any abnormality in sound

GENERAL OBSERVATIONS

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

NO-LOAD ELECTRICALPARAMETERS

Check the voltage on No-load b/w body and neutral-it should be less than 3

volts

ENSURE PROPER EARTHING

Proper tightening of all screws including base frame

There should be no loose connection

VISUAL OBSERVATION

CHECK POINTSPOINT OF OBSERVATION

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TROUBLE SHOOTING

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VOLTAGE FAULTS

1. Reset the speed to the nominal

2. Replace the Rotating rectifier

3. Check the wdg. Resistance

Rewind if required

1. Low speed

2. Faulty Rotating rectifier

3. Faulty Winding

Low no-load

voltage

1.Excite the exc.stator using a battery

2. Correct the connection

3. Reset the speed to the nominal


Rewind if required

5. Replace the rotating rectifier

6. Replace the AVR

1.Insufficient residual voltage

2. Improper connection

3. Low speed

4. Faulty Winding

5.Rotating rectifier failure

6. Faulty AVR

No voltage built-up

REPAIRCAUSEFAULT

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1. Correct the load

2. Tightend the loose connections


Rewind if required

1. Unbalance Load

2. Loose connections

3. Stator winding faulty

Unbalance

voltage

1. Set the AVR stability pot

2. Reduce the Tghyristor load

1. In correct AVR setting

2. Thyristor load more

than specified limits

Voltage

Oscillations

REPAIRCAUSEFAULT

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1. Adjust the speed1. Excessive speedToo high

No-load voltage

1. Disconnect the PF improvement

capacitor

1. Capacitor on the load sideHigh voltage on

load

1. Set the rated speed of the Engine


Rewind if required

3. Operate on specified load.

1. Low speed at full load.

2. Faulty rotor Winding

3. Over load on Alternator

Low voltage on

load

REPAIRCAUSEFAULT

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HOW TO SELECT

ALTERNATOR RATING

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DERATING FACTORS

No deration upto Std. Amb : 40c .

DERATION FOR AMB. TEMP.

0.75

0.8

0.85

0.9

0.95

1

1.05

AMB. TEMP

DE

RA

TIN

G F

AC

TO

R

D.Factor 1 0.96 0.92 0.88 0.84

40 45 50 55 60

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No deration upto Std. Altitude level : 1000 M .

DERATION FOR ALTITUDE.

0

0.2

0.4

0.6

0.8

1

1.2

ALTITUDE

DE

RA

TIN

G F

AC

TO

R

D.Factor 1 0.96 0.92 0.88 0.84 0.8

1000 1500 2000 2500 3000 3500

DERATING FACTORS CONTD..

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No deration for UPF to 0.8 Pf

DERATION FOR POWER FACTOR( LAG)

0.75

0.8

0.85

0.9

0.95

1

1.05

POWER FACTOR

DE

RA

TIN

G F

AC

TO

R

D.Factor 1 0.95 0.91 0.88 0.86 0.85 0.84 0.84 0.84

0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

DERATING FACTORS CONTD..

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SELECTION OF ALT. FOR VARIOUSLOADS

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.

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SELECTION OF ALT. FOR VARIOUSLOADSCONTD..

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

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SELECTION OF ALT. FOR VARIOUSLOADS

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,sorequired derating.

Alternator KVA rating = 1.5 X + Y

Where X is thyristor load & Y is linear load.

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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,

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GUIDELINES FORNON-LINEAR LOADS

Non linear load should not exceed 35%of the alternator rating

UPS & TELECOM LOAD CONTROLLED BY ATHREE PULSE THYRISTOR BRIDGE PLUS AFILTER


VARIABLE SPEED 6 PULSE THYRISTORBRIDGE CONTROL DRIVE.


UPS & TELECOM LOAD CONTROLLED BY ASIX PULSE THYRISTOR BRIDGE PLUS AFILTER


UPS & TELECOM LOAD CONTROLLED BY ATWELVE PULSE THYRISTOR BRIDGE PLUSA FILTER

No derating required.FLOURESCENT LIGHTING LOAD

GUIDELINESLOAD

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REMEDIES FORNON-LINEAR LOAD

Oversize of the neutral conductor (200% of the phaseconductor).

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.

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REMEDIES FORNON-LINEAR LOAD

Oversize of the neutral conductor (200% of the phaseconductor).

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.

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RELATION B/T STARTING METHOD &STARTING CURRENT

1.2 times the full load current



AUTO TRANSFORMER STARTING

40% Tapping

60% Tapping

80% Tapping

1.5-2 times the full load currentROTOR RESISTANCE

2-2.5 times of the full load currentSTAR/DELTA STARTING

6-7 times of the rated full load current

( If starting current is not given than startingKVA is 7 times HP rating)

DIRECT ON-LINE STARTING (DOL)

STARTING CURRENTMETHOD OF STARTING

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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

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HOW TO SELECT ENGINE RATING..?

ENGINE HP IS GIVEN BY:-

(KVA * PF) /( 0.735 * Efficiency of alternator)

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Thank you

Brushless ALTERNATOR Customer Training

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Transcript of Brushless ALTERNATOR Customer Training