Day 1 Part 1 - AVR Concept

8/12/2019 Day 1 Part 1 - AVR Concept

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Questions on Electricity

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Who Invented Electricity?


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Who Discovered Electricity?

Benjamin Franklin

(1706 1790)

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1752 The Kite experiment 600 BC Thales of Miletus

Benjamin Franklin


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1752 The Kite experiment

600 BC Thales of MiletusAmber


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AMBER =!"#$%&'((Greek)

AMBER = Elector(Greek)


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1752 The Kite experiment

600 BC Thales of Miletus

Elector = Greek God, Awakener


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x 50,000

Electron

Elector = Greek God, Awakener

Generator

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How it all started?


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Generator How it all Started?

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Discovery of Electricity

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Discovery of Magnetism



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Discovery of Link Between Electricity & Magnetism


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For Motor

Discovery of Link Between Electricity & Magnetism


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Discovery of Electricity + Magnetism + Force


For Motor

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Force

(Motion)

Electricity

Magnetism

For Motor


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First Generator Built in 1663 By Otto von Guericke Work on Electrostatic

1663 Electrostatic Generator

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1791 Discovery of EMF By Alessandro Volta !

The voltage or electric potential difference across the

terminals of a cell when no current is drawn from it.

Definition:



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Tank

Battery

Switch

Bulb

Tap

Water

Wheel

Electrical vs Water Analogy

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Source

Source

Control

Load

Control

Load

Electrical vs Water Analogy


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Generator How it all Started?Analogy of Voltage

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Analogy of Current


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Generator How it all Started?Analogy of Voltage

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By Andr-Marie Ampre

!


1791 Discovery of EMF 1820 Link between Magnet & Current By Hans Christian ersted

Electromagnetism


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Electromagnetism

Relationship between Electric Current & Magnetic Field

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Electromagnetism

Relationship between Electric Current & Magnetic Field


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! 1663 Electrostatic Generator 1791 Discovery of EMF 1820 Electromagnetism

How it all started

1821 Electromagnetism and MotionMichael Faraday

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Current produces force on each others


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Motor or Generator ?

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Electromagnetism

Relationship Between Electromagnetism & Force

For Motor For Generator

Flemings Left Hand Rule


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Motor or Generator ?

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Curre

nt


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Motor

Curre

nt

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Generator


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Generator

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Generator


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Generator - Dynamo

Curre

nt

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Generator - Dynamo

Curre

nt


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Generator - Dynamo

Curre

nt

Slip Ring


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Dynamo DC Generator

Curre

nt

Split Ring

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Dynamo DC Generator

Curre

nt

Thomas Edison


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Dynamo DC Generator

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Generator - Dynamo


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Thomas Edison Nikola Tesla

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AC Power System


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Transformer

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HVDC Transmission


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AC Synchronous Alternator

ACOutput

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Permanent Magnet Generator PMG


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ACOutput

2 StatorPoles

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Permanent Magnet

2 Rotor Poles

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ACOutput

Permanent Magnet2 Rotor Poles

2 StatorPoles

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A Nollet electro-magneto generator, using permanent magnets, invented in 1850

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0 90 180 270 360 450 540 630 720

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3 Stator Poles

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C

A

B

3 Stator Poles

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A

B

C

A

B

C

GeneratorWindings

6 Stator Poles

4 Rotor Poles

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Frequency =RPM x Number of Poles

120

FrequencyIn Hertz 2-Pole 4-Pole 6-Pole 8-Pole

60 3600 1800 1200 900

A

B

C

A

B

C

4 Rotor Poles

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LOAD

Example of PMG curve

CurrentPM

G

outputvoltage(Vrms)

+

++

++ ++

+

0/4 ceiling4/4

(at nominal speed)

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Power Electric Converter (Inverter)

ACDC AC

DC

Rectification Modulation

BatteryCharging

Wind Turbine PMG Generator

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A

B

C

A

B

C

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LOAD

Example of PMG curve

CurrentPMG

outputvoltage(Vrms)

+

++

++ + +

+

0/4 ceiling4/4

(at nominal speed)

LOAD

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Static Excitation


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Slip RingsSplit Rings

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Types of Commutations

Generator Output

ExcitationInput

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Brushless Excitation


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Generator Output

ExcitationInput

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Brushless Excitation

Murray Alternator with Belt Driven ExciterMurray alternating current direct-connected unit with high speed Corliss engine

and belt-driven exciter, 50, 75, 100 KVA alternator and 150 RPM engine.

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Generator in earlier days..


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Meidensha 21.92 MVA, 11kV

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Synchronous Generator Rotary Exciter

Excitor

Main RotorPMG

Main Stator Winding



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Bearing

Shaft

Rectifier

Exciter

Rotor

& Stator

Main Stator

Fan

Main RotorMain Rotor


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High-remanence steel core Stores Residual Magnetism 10 - 14 pole magnet field High frequency Generator

XX- (F2)

X+ (F1)

N S N S

COIL CONNECTIONS

To A.V.R Output terminalsExcitation System Wound Exciter Stator


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3 Phase A.C output, each Phase connected to 2 diodes on Main Rectifier. High Frequency output, ( from 10 to 14 Pole Exciter Stator ). Exciter generator is a magnetic power amplifier supplying the main rotor current.

SHAFT

W U

W

U

VV

Excitation System Wound Exciter Rotor

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SHAFT

W U

W

U

V

V

The Rectifier assembly is mounted on Exciter Rotor Core, (drive end side). NOTE: BC & Frame 8 Generators are mounted at the non-drive end side.

Wound ExciterRotor

Exciter Rotor & Main Rectifier Assembly

RectifierAssembly

SHAFT

A.C Input connections

D.C Output

connections


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SHAFT

Exciter Rotor 3 Phasewith Internal Star Point

Each phase is connected to a positive and negative Diode

Exciter Rotor & Main Rectifier Connections

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SHAFTSHAFT

3 Phase A.C Exciter Rotor Connected to Rectifier input terminals

Rectifier Input

Terminals (A.C)

Rectifier Output (D.C)

To Main Rotor



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A.C output from theExciter Rotor is rectified

from A.C, to D.C, by theMain Rectifier assembly.

Rectifier

Assembly

Exciter

Stator

ExciterRotor

A V RXX- (F2)

X+ (F1)

SHAFTSHAFT

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SHAFT

Main Rectifier Assembly

Varistor(Surge Suppressor)

3 Phase A.C Input

from ExciterRotor(Insulated

Terminals)

! Rectifier DiodesPositive Plate

Cathode Stud

Rectifier DiodesNegative Plate

Anode Stud

DIODE MIN. 25 AMP 800 VOLTAluminium

Heat-sinks

! Split Two-PieceRectifier Hub


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+VE

0

-VE Rectifier DiodePositive Heatsink

Cathode Stud

Rectifier DiodeNegative Heatsink

Anode Stud

+VE

0

-VE

+VE

0

-VE

A.C Input to RectifierDiodes( 150 HZ to 180 HZ per

second)

+

Main Rectifier Assembly Operation of a Diode

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Full wave 3 Phase rectification will produce a D.C output of 1.35 X A.C input voltage

A.C Input to Rectifier Diodes (150 to 180HZ)

D.C output to Main Rotor+

-

Main Rectifier Assembly 3 Phase rectification


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SHAFT

Metal Oxide Varistor (Surge Suppressor)

Clamping @ 100 Amp 1365 Volts Clamping @ 30 Amp 680 Volts

Diode Protection Device

For Transient Suppression

Main RotorConnectionsSHAFT

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Direction of D.C current to Main rotor

Typical high voltage transient created by faultcondition in the distribution system.

Up to 2- 3000V (peak voltage)

Varistor clamping

level.

UC/BC 680V

HC/F8 1365V

Crash Synchronising onto live bus-bars. Electric storm, (lightning), and field effects on

overhead lines (distribution systems).

Arcing, caused by faulty switching, motorfailure, short circuits in the distribution system.

Full load D.C

output frommain Rectifier

t = "sec's

duration.

Direction

of faulttransient

Energy absorbed

by Varistor.High Transient surges can be created by:-

DIODE PROTECTION DEVICE

Metal Oxide Varistor (Surge Suppressor)


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SHAFT D.C

Main Rotor

The Rectifier Output is a smooth D.C Supply across the Aluminium Heat Sinks This is fed to the Main Rotor windings

Main RectifierMain Rotor connections to Main Rectifier

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S

S

N N

D.C Input

From Main

Rectifier

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

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

ANTICLOCK

CLOCKCLOCK

ANTICLOCK

Main Rotor Winding Coil Group connections


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SHAFT

S

S

NN

Wound Main Rotor - Poles & Frequency

Main Stator Coils in Slots (section)

4 Pole Main Rotor

The NEGATIVE Pole of the 4 pole Rotor is directly under the slot, therefore thecoil conductors in this slot will be going fully NEGATIVE

Main Stator Core(section)

Air Gap

Consider the Coils in the slot at 12 O'clock position, marked with the ARROW.1 Cycle

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The coil conductors in this slot will now be at ZERO VOLTAGE. The Rotor has now rotated Clockwise 45 , until exactly half-way between

Negative and Positive Poles appears beneath the 12 O'clock position.

SHAFT

S

S

NN

4 Pole Main Rotor

Main Stator Core

(section)

Air Gap


1 Cycle



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The coil conductors in this slot will now be at the FULLY POSITIVE position The Rotor has now rotated Clockwise 90 , until the POSITIVE Pole is DIRECTLY

UNDERNEATH the 12 O'clock position.

The 4 Poles will produce 2 FULL CYCLES for each 360 FULL REVOLUTION.

SHAFT

S

S

NN

4 Pole Main Rotor

Main Stator Core(section)

Air Gap


1 Cycle


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SHAFT

S

S

NN SHAFT

S

S

NN

N

S

4 Pole2 Pole

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

120

SHAFT

S

N

6 Pole



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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 C Temperature rise in 40C Ambient. 2/3rds Pitch windings, Triplen ( 3rd, 9th, ect.), Harmonics virtually eliminated.

Laminated Steel core Copper WindingsOutput Leads

Wound Main Stator Assembly

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OUTPUT

CONDUCTORS

COIL PHASE GROUP

OUTPUT CONDUCTORS

Stator Winding Coils (Lap winding)

The output voltage of the stator is determined by the number of turns per coil, thestator core length, the velocity of the magnetic field (rotor), and the strength of the

magnetic field. The Current capacity of the coil is determined by the copper conductors cross

sectional area, and number of conductors in parallel.

STATOR

CORE

LENGTH

COIL END

(OVERHANG)

COIL

TURNS

COIL

SPAN

(PITCH)

Wound Main Stator Assembly


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U5

W2

V5

U5

W

2

V5

W5V2

W5 V2

MAIN ROTOR

(4 POLE)

Typical Main Stator 12 Wire Re-connectable

WINDING LEADS

START OF COIL

GROUP

WINDING LEADS

FINISH OF COIL

GROUP

GROUP 1

GROUP 4GROUP3

GROUP 2

MAIN STATOR WINDING

SECTION ( 48 SLOT )

2/3RDS PITCH = 2/3RDX 12

= 8 SLOTS

( SPAN 1 TO 9)

COILS PER GROUP

= 48/12 = 4

FULL PITCH = 12 SLOTS

( SPAN 1 - 13)

SHAFT

S

S

NN

V6

U6

W1V6

W6

V1

W6

V1

U6

W1

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AVR Sensing

& Power supply

from Main Stator

3 Phase Output

Neutral

Connections shown in Series Star

Typical Main Stator 12 Wire Re-connectable

6

7

8 U

V

W

NV6

W5

V2

W6

U6

W1

V1

U1

V5

U2

U5

W2


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Wound Main Stator 12 Wire Re-connectable

Voltage Range (for winding 311)380 to 440 V @ 50 HZ

416 to 480 V @ 60 HZ

Voltage Range (for winding 311)190 to 220 V @ 50 HZ

208 to 240 V @ 60 HZ

Series Star

U1

U2

U6

U5

V2

W2W5

V6

V1

W1V5

W6

U

w v

N

8

7

6

Parallel Star

V5

U1

U2 U6

U5

V2

W2

W5

V6

V1

W1

W6vw

U

N

6

8

7

The stator windings are connected into six groups. The groups can be connected by Newage, or the customer, to provide different voltage requirements. Special Voltage requirements require special windings, e.g.; 600 Volt for Canada.

Voltage Range (winding 311) 220 to 250 V @ 50 HZ, 240 to 277 V @ 60 HZ No Neutral connection. Centre Tap for low volts (low current only)

Voltage Range (Winding 311) 220 to 250 V @ 50 HZ, 240 to 277 V @ 60 HZ Single Phase Only, output across U & W Centre Tap (N) for low volts 110 to 125 @ 50 HZ, 120 to 138 @ 60 HZ

Series Delta

U1

U2

U5

W6

U

W2

W5

V6

W1

w

U6

V2 V1V5

v

Centre

Tap

6

8

7

Double Delta

U1 U2

U

W2

V6 W1

V5

U5

W6

W5

w

U6

V2

V1

N

7

6

8

Wound Main Stator 12 Wire Re-connectable


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Number of Stator leads in parallelincreases with current rating

of generator,

ie: 12, 18, 24, 36, or 48 leads out.

Voltage Range (winding312)

380 to 440 V @ 50 HZ416 to 480 V @ 60 HZ

Single Phase (N)

= LL / 3

Dropper transformer

required

for AVR sensing

Star connection

U

U1

U2

V2W2

V1W1

w v

N

7

6

8

Each phase group is producing the full LINE to NEUTRAL voltage, ( Coil groups in each phase are in four parallel circuits). The AVR cannot be connected directly to 6,7,and 8, for sensing signal or power

Wound Main Stator Ends Out

The AVR Sensing supply is connected to the main stator via a sensingisolation transformer, which is fitted in the main terminal box.

SENSING SUPPLY FOR A.V.R IN STAR CONNECTION

7

6

8

7

6

Isolation transformer

Other windings producing higher voltage requirements will require a differenttransformer ratio, to supply the AVR with the correct voltage adjustment range

Examples - 6 ends Stators

Winding 312

380 to 440 V @ 50 HZ

416 to 480 V @ 60 HZ

Single Phase (N) = L-L / 3

Winding 26

660 - 690 Volts @ 50 HZ

8

V

Star connection

U

U1

U2

V2W2

V1W1

N

W

Wound Main Stator Ends Out


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X+ (F1)

XX- (F2)D.C Output

From A.V.R

Into

Exciter Stator

A.C Power &Feedback Signal

(Sensing)

From Main Stator

Operation of the Self Excited Generator

A.V.R

Bearing

Shaft

Rectifier

Exciter

Rotor

& Stator

Main Stator

Fan


The Permanent Magnet Generator (PMG)

! Generator Shaft (Non-Drive -End)

Dowel Pin for PMG Rotor Location

Through Bolt fixture to Shaft non drive end Permanent Magnet Stator 3 Phase A.C 170 to 220 Volts, separate

power supply for the A.V.R

P2, P3, P4 Power Supply To A.V.R

Ceramic Magnet Rotor, highly magnetic saturated field. 8 Pole Rotor ,100 HZ (at 1500 RPM ) or 120 HZ (at 1800 RPM )

Operation of the Separately Excited Generator


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Operation of a Separately Excited Generators

X+ (F1)

XX- (F2)

PMG

Power

Supply

To A.V.R

A.C Sensing

Supply From

Main Stator

(2 or 3 Phase)

P2 -P3 -P4

6-7-8A.V.R

THE PMG GENERATOR PROVIDES A SEPARATE POWER SUPPLY FOR AVR

Bearing

Shaft

Rectifier

Exciter

Rotor

& Stator

Main Stator

Fan


ADVANTAGES OF SEPARATE EXCITATION SYSTEM

UNAFFECTED BY WAVEFORM DISTORTION CAUSED BY NON LINEAR LOADS

POWERFUL VOLTAGE BUILD UP SYSTEM ON INITIAL RUN-UP, DOES NOT RELYUPON RESIDUAL MAGNETISM.

SUSTAINED SHORT CIRCUIT CURRENT UNDER FAULT CONDITIONS,

ISOLATED POWER SUPPLY FOR THE AVR, (PROTECTS AVR FROM HIGHTRANSIENT FAULT CONDITIONS IN THE DISTRIBUTION SYSTEM)

CAPABLE OF VOLTAGE BUILD UP AGAINST LOAD, (FREQUENCY STARTING OFLARGE MOTORS).

Operation of a Separately Excited Generators


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%9:;669 :6 '393;B:6; B9< +J5K:B>69 LMF:37

GENERATOR CONTROL SYSTEM

SPEED

GOVERNOR

PRIME

MOVER

EXCITER

ELECTRICAL

LOAD

PROTECTION

REGULATION

AND

CONTROL

GENERATOR

%9:;669 :6 '393;B:6; B9< +J5K:B>69 LMF:37

- The function of the voltage regulator is to provide preciseregulated generator voltage at no load and changing loads.

VOLTAGE REGULATOR

GENERATOR VOLTAGE REGULATION

- Is expressed as the difference between the no load valueof voltage as compared to the full-load value for fixedvalues of DC current applied to the field.

VNL VFL X 100

Day 1 Part 1 - AVR Concept

Documents

Transcript of Day 1 Part 1 - AVR Concept