1

TRAINING WIN-S

TS-E/TRG/2000

PARALLEL OPERATION

OF

DIESEL GENERATOR

2

TRAINING WIN-S

TS-E/TRG/2000

PARALLEL OPERATION OF D.G. SETS PARALLEL OPERATION OF D.G. SETS

SYNCHRONISINGSYNCHRONISING SYNCHRONISINGSYNCHRONISING

AFTER SYNCHRONISING ?AFTER SYNCHRONISING ?

PARALLEL OPERATIONPARALLEL OPERATION

3

TRAINING WIN-S

TS-E/TRG/2000

SYNCHRONISING SYNCHRONISING

BASIC REQUIREMENTSBASIC REQUIREMENTS

CONDITIONS TO BE CHECKED ON INCOMER & BUSBAR

EQUAL RMS VOLTAGES

SAME PHASE SEQUENCE

EQUAL FREQUENCIES

EQUAL INSTANTENUOUS VOLTAGE

(CHECK FOR SYNCHRONISM)

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TRAINING WIN-S

TS-E/TRG/2000

SYNCHRONISING SYNCHRONISING CONTROL SYSTEM REQUIREMENT

COMPARE MAGNITUDE AND FREQUENCY, INDICATE THE RELATIVE STATUS FACILITATE ADJUSTMENT OF VOLTAGE AND

FREQUENCY - MANUAL OR AUTO CHECK FOR SYNCHRONISM FACILITATE SYNCH. BRKR CLOSURE - MANUAL

OR AUTO ISOLATE SYNCH. SYSTEMS AFTER BREAKER

CLOSURE - MANUAL OR AUTO

5

TRAINING WIN-S

TS-E/TRG/2000

SYNCHRONISING SYNCHRONISING

DOUBLE VOLTMETER DOUBLE FREQUENCY METER SYNCHROSCOPE - CHECK SYNCHRONISING RELAY AUTO SYNCHRONISER PROGRAMMABLE LOGIC CONTROLLERS

DEVICES USED

6

TRAINING WIN-S

TS-E/TRG/2000

SYNCHRONISING SYNCHRONISING SYNCHRONISING FIRST TIME!

EMPLOY ‘PHASING OUT’ TECHNIQUES - USING

A. ON SECONDARY SIDE OF P.T

PHASE SEQUENCE INDICTOR

LAMP METHOD

ANALOGUE MULTIMETER

B. ON H.T. SIDE

HT PHASING PROBES

BY STARTING AN AC MOTOR WHOSE D.O.R ALREADY CONFIRMED WITH EXISTING

SOURCE

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TRAINING WIN-S

TS-E/TRG/2000

SYNCHRONISINGSYNCHRONISING

• MAINTAIN SPEED & VOLTAGE HIGHER TO PREVENT REVERSE POWER OR REVERSE KVAR TRIP.

• NEUTRAL OF ONE M/C TO REMAIN CLOSED TO PREVENT EARTH FAULT RELAY OPERATION.

• MAY BE NECESSARY TO FLOAT ALL NEUTRALS DURING GRID PARALLEL OPERATION.

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TRAINING WIN-S

TS-E/TRG/2000

MODES OF PARALLEL OPERATION OF D.G. SETS MODES OF PARALLEL OPERATION OF D.G. SETS

GRID PARALLEL MODE

ONE OR MORE SETS IN PARALLEL WITH GRID

ISLAND PARALLEL MODE

MORE THAN ONE SET SHARING COMMON LOAD

END

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TRAINING WIN-S

TS-E/TRG/2000

GRID PARALLEL OPERATION GRID PARALLEL OPERATION STABLE GRID. – DG CONTINUES TO SUPPLY KW & KVAR AS

SET INITIALLY. UNSTABLE GRID.– KW DECREASES WITH INCREASE IN GRID

FREQUENCY AND VICE VERSA.– KVAR DECREASES WITH GRID INCREASE IN

VOLTAGE AND VICE VERSA.

10

TRAINING WIN-S

TS-E/TRG/2000

GRID PARALLEL OPERATION GRID PARALLEL OPERATION HOW TO CONTROL?

AUTOMATIC KW REGULATOR & GOVERNOR

MOTOR TO ADJUST SPEED OF ENGINE TO

MAINTAIN KW LOAD.

AUTOMATIC KVAR / PF REGULATOR & AVR TO

ADJUST VOLTAGE OF THE ALTERNATOR TO

MAINTAIN THE SET POWER FACTOR AND

HENCE KVAR LOAD.

• PLCS CAN ALSO BE USED TO MAINTAIN KW

AND KVAR LOAD1

11

TRAINING WIN-S

TS-E/TRG/2000

GRID PARALLEL OPERATION GRID PARALLEL OPERATION

DIFFICULTIES

REVERSE POWER FLOW TO GRID, WHEN

GENERATION IS MORE THAN DEMAND

GRID FAILS WITHOUT PHYSICAL

ISOLATION

OVERLOAD CAUSED BY TRANSFER OF GRID

SHARE OF PLANT LOAD ON RUNNING DGs.

OVER VOLTAGE DUE TO LEADING POWER FACTOR

CAUSED BY EXCESS POWER FACTOR IMPROVING

CAPACITORS.

12

TRAINING WIN-S

TS-E/TRG/2000

GRID PARALLEL OPERATION GRID PARALLEL OPERATION

HOW TO OVERCOME THE DIFFICULTIES?

USE OF DIRECTIONAL POWER RELAY AND GRID SENSING RELAY TO SENSE GRID FAILURE AND TO,

ISOLATE GRID DEACTIVATE REGULATORS ISOLATE NON ESSENTIAL LOADS ISOLATE PF IMPROVING CAPACITORS

13

TRAINING WIN-S

TS-E/TRG/2000

GRID PARALLEL OPERATION GRID PARALLEL OPERATION

MOST IMPORTANT !

PROVIDE INTERLOCKS TO PREVENT GRID

BREAKER CLOSURE WITHOUT SYNCHRONISING

WHEN GRID SUPPLY RESUMES

14

TRAINING WIN-S

TS-E/TRG/2000

SPEED (VOLTAGE) DROOPSPEED (VOLTAGE) DROOP Solo Mode

%DROOP = (NO LOAD VALUE - FULL LOAD VALUE) X 100

RATED VALUE

SPEED (VOLTAGE) DROOP IS THE REDUCTION IN SPEED (VOLTAGE) FROM NO LOAD SPEED (VOLTAGE) VALUE TO FULL LOAD VALUE. EXPRESSED AS PERCENTAGE OF RATED VALUE ;

15

TRAINING WIN-S

TS-E/TRG/2000

ISLAND PARALLEL OPERATION ISLAND PARALLEL OPERATION

1

2

RELATION BETWEEN DROOP AND LOAD SHARING

CAPACITY DROOP LOAD SHARING

UNEQUAL

UNEQUAL

EQUAL

EQUAL

UNEQUAL

EQUAL

UNEQUAL

EQUAL

PROPORTIONAL TO CAPACITY

LOWER DROOP - HIGHER LOAD AND VICE VERSA

EQUAL

PROPORTIONAL TO CAPACITY & INVERSLEY PROPORTIONAL TO DROOP

16

TRAINING WIN-S

TS-E/TRG/2000

ISLAND PARALLEL OPERATION ISLAND PARALLEL OPERATION

DIFFICULTIES ENCOUNTERED

VARIATIONS IN LOAD SHARING - ENGINE OR

GOVERNOR RESPONSE

DIFFICULTY TO SHARE TO ‘DERATED’

CAPACITY

FALL IN SYSTEM FREQUENCY AND VOLTAGE -

DROOP CHARACTERISTICS

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TRAINING WIN-S

TS-E/TRG/2000

ISLAND PARALLEL OPERATION ISLAND PARALLEL OPERATION

HOW TO OVERCOME?

ISOCHRONOUS MODE - DROOP OF ONE DG

IS SET LESS THAN THE OTHERS ( MASTER

SLAVE CONCEPT)

USING SUITABLE CONTROL SYSTEMS

18

TRAINING WIN-S

TS-E/TRG/2000

NOMINAL SPEEDOPERATING SPEED

50 Hz

49 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

48 _ _ _ _ _ _ __ _ __ _ __ _ _ __ __ __ _ _ _ _ __ _ _ _ _ _ _

47 _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ __ M/c 1

LOAD on M/c 2 M/c 2

F R

E Q U E N C Y

LOAD ON M/c 1

0 0

LOAD - %100%

LOAD SHARING BETWEEN TWO MACHINESEQUAL RATINGS - DIFFERENT DROOPS

19

TRAINING WIN-S

TS-E/TRG/2000

NOMINAL SPEED OPERATING SPEED 1OPERATING SPEED 2

50 Hz

49 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 48 _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _|_ _ _ _ _ _ _ _| __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

| | | | | 4 MW | 6 MW

| | || | || | |

F | | |R | | |E | | |Q | | |U | | |E | | |N | | |C LOAD ON 6MW | SET | |Y AT OP. SP 1 | | |

| | | LOAD ON 4MW | | | SET AT OP.SP-1 | | |

| | | LOAD ON 4 MW | SET | | AT OP. SP - 2 | | | | | |

| | || | || | |

LOAD ON 6 MW | SET AT OP | SP - 2 || | |! ! !

0 2 MW 4 MW 6 MW4.5 MW

LOAD

3 MW

LOAD SHARING BETWEEN TWO MACHINESDIFFERENT RATINGS - EQUAL DROOP