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2. 210 MW GENERATOR OPERATING INSTRUCTIONS / STAGE – I I 2.1INTRODUCTION 01. PRE-STARTING OPERATIONS The following operations/checks are to be carried carried out by the Generator Board Engineer, prior to putting the generator into service. s ervice.
02. CHECKS TO BE DONE AFTER RECEIVING INSTRUCTIONS FOR STARTING UP The following conditions are to be checked/ascertained checked/ascertained after receiving receiving instructions for starting up of the unit from Shift Engineer. Engineer. . !o line line clea clears rs are are pend pendin ing g on the the gene genera rato torr and and the the conn connec ecte ted d e"uipments. #. $heck $heck the Seal oil system system is in normal normal service service and the %# pressure pressure is normal. &!ot less than '.' (g/$m# and at )* + purity. -ut the other Sin 0T reserve. '. Star Startt any any one one of the stator stator water water pumps pumps and put put the the othe otherr S1S1- in 0T reserve. d2ust the S.1.3ow to #4.5 m'/hr and monitor the 3ow and conductivity of the water. 6eset the master trip relays *7G' 8*7 G9 at G6-. 9. Switch Switch on the heaters heaters and rapping motors motors at ES- after after con:rming con:rming there there is no line clearance is pending. ;. $heck $heck and ensure ensure that all all the fuses fuses at G6G6- are intact intact.. 7. $heck $heck and reset reset all the relay relays s at the G6-. 4. Ensure Ensure that the 6otor 6otor earth earth fault protectio protection n selector selector switch at G6- is in <= 6T6 E/>? position. *. E@ect E@ect the .$. supply supply by switching switching on the switches switches $SA and $SA# $SA# at G6-. ). $hec $heck k the the lamp lamps s in the the annun annunci ciat atio ion n wind window ows s at Gene Genera rato torr cont contrrol desk desk cum cum pane panell &G$ &G$- - and and comm common on u uCi Cili liar ary y -anel anel &$&$- by operating the respective lamps test push buttons. 5.. $hec 5 $heck k the the $ fail fail moni monito tori ring ng cir circuit cuits s for for Sour Source ceA A / Sour Source ceA# A# $ supp su ppli lies es by pres pressi sing ng the the push push butt button ons s -B -BA A//-BA BA# # at G$G$-. 1hil 1hile e
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pressing these push buttons <$ S06$EA fail? <$ S06$EA #?appear at G$-. . $on:rm from switchyard control room &SD$6 sta@ that all the earth switches in the Generator connecting line are kept open. #. $heck the GeneratorATransformer > at local and ensure the following. a. Tap changer control supply and cooler control supply are switched on. b. The local/remote selector switch of tap changer is in remoteF position. c. The cooler power supply is from ainF source. d. The auto/manual selector switch of cooler control is in autoF position. e. =ndividual !/>> switches of the fans are in !F position. f. The air pressure of mulsi:er system is normal. '. $heck the supply to GT HT$ panel at 0$B is available. 9. $heck for proper operation &closing/opening of = Bus, == Bus and line isolators one by one after informing switchyard control room &S$D6 sta@. Each time when an isolator is closed/opened observe for the corresponding lamp indication at G$-, corresponding position of the semaphore indicator at SD$6 and also the physical conformation from local through SD$6 sta@ that the isolator has properly closed/opened. 1hile checking for the proper closing of = Bus / == Bus isolator, check for the normal reading of 955 (I bus voltmeters of all the three phases after closing of the isolator. fter completing the testing of all the isolators keep all the isolators in open condition. ;. >or checking the proper opening of Generator breaker ;# GB carry out the followingJ a.
Ensure that the Bus Bar protection &BB trip relay )7 GT at SD$6 is in resetF condition.
b.
Ensure that the protection transfer switch &-TS of generator at SD$6 is in !ormalF position.
c.
Ensure that the -TS of generator at G$- is in !ormalF position.
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d.
Ensure that the SES control supply is switched o@, i.e. ;#B at the crowbar cabinet in ses room is in >>F position to prevent the tripping of ;#GB on 0ltimately interventionF protection while closing it.
e.
(eep the synchronising selector switch &SSS of generator in manualF position.
f.
anually, actuate the #;C relay at G6- and close the GB. fter GB closed release #;C and observe for the following indication. i.
GBF close A lamp indication at G$-.
ii.
$orresponding semaphore indication at SD$6.
iii.
!F indication at GB local.
iv.
Springs chargedF lamp indication after closing of GB.
g.
Switch o@ the synchronising selector switch. i.
GB openF lamp indication at G$-.
ii.
$orresponding semaphore indication at SD$6.
iii.
>>F indication at GB local.
h.
Select the voltage regulator to manualF.
i.
Ensure that the manual reference potentiometer is in minF position with the lamp indication.
2.
Ensure that the SE- room cooling is suKcient by checking ir conditioning boCes and blowers.
7. $heck and ensure that the following parameters are within their limits. i.
i@erential pressure between % # and oil L.; (g/$m#.
ii.
Seal oil pressure temperature at the cooler outlet L 95 $.
iii.
%# pressure L above '.' (g/$m #.
iv.
$old gas temperature L below 97 $.
v.
%ot gas temperature L below 4; $.
vi.
°
°
%# purity L )*+.
4. Ensure that all the four valves in the gas cooler inlet header and outlet header are in open condition. *. Switch on all the recorders and indicating instruments in the Generator panel at 0$B.
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). Switch on the supply to igital 1 indicator. #5. !ote down the initial readings in all the energy meters.
2.2 SYNCHRONISING THE GENERATOR WITH THE GRID .
Ensure that the seal oil system are normal and watch the parameters of seal oil system, S1S and gas system, reset all the relays at G6-.
#.
Switch on the switches $SA and $SA# at G6- to e@ect .$. supply to G6-.
'.
1hile rolling the turbine, check the generator bearing vibration and ascertain that it is within normal values.
9.
Turbine is being warmed up, close the 955 (I = bus or == bus isolator accordingly after con:rming from SD$6 sta@ to which bus the unit is to be connected. bserve for closed lamp indication at G$-, normal reading in the bus voltmeter for all the three phases at G$-, proper semaphore indication at SD$6 and get physical con:rmation for proper closing from local through SD$6 sta@.
;.
$lose the 955 (I line isolator and observe for closed lamp indication at G$-, proper semaphore indication at SD$6 and get physical con:rmation for proper closing from local through SD$6 sta@. a.
Ensure that the voltage regulator is in the anualF mode.
b.
Ensure that the manual reference potentiometer is in the minimumF position by observing for the corresponding lamp indication.
c.
bserve for start enablingF lamp indication.
d.
Ensure that the :eld breaker is racked in.
e.
-ress the startF -B and observe for :led breaker closed lamp indication at G$-.
f.
bserve for normal readings in rotor voltmeter and rotor ammeter, which corresponds to no load eCcitation. Generator terminal voltage should rise to around # (I in about ' secondsM check this in all ' phaseM if not >B will trip with >lashing time delayF indication at local alarm panel. =n that case check the generator -T circuit fuses, actual speed and the :eld 3ashing circuit.
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g.
=f the generator terminal voltage reaches about # (I within ' seconds, ensure the healthiness of all the siCAconverter bridge and ensure that there is no alarm persisting in the local alarm panel.
7.
Build up the generator terminal voltage in FanualF mode upto ;.4; (I by operating the =ncreaseF -B of the manual channel.
4.
1hen the terminal voltage is around ;.4; (I ad2ust the balance voltmeter reading to Nero by pressing the =ncrease/ecrease push buttons of uto channel.
*.
1ith Nero reading in the balance voltmeter change over the mode of voltage regulator to uto by pressing the utoF push button.
).
Ensure the -TS at G$- is in !ormalF position.
5.
Switch on the generator SSS to anualF position and see that the
double voltmeter 8 double fre"uency meter at G$- have come into service. .
$heck for the Ioltage e"ualiser onF indication and synchronising
EnableF indication at G$-. #.
$ompare the voltage and fre"uency of the incoming generator with the
respective parameters of the grid. '.
&Speed of turbine to make it e"ual &slightly higher with that of the
grid with the help of speed changer at G$-. 1hen turbine rolling is done with E%$ speed variation can be done from E%$ desk insert only. 9.
Switch on the synchroscope switch at G$-.
;.
bserve that the synchroscope pointer rotates in the >astF &clockwise
direction and synchronising permissiveF lamp at G$- glows whenever the pointer reaches the # F clock position. The synchroscope will rotate in the >astF direction only when the fre"uency of the generator is higher than the grid &generator is fasterF than the gridM otherwise it will rotate in slowF &anticlockwise direction. To make it rotate is the >astF direction the speed of turbine is to be increased. 7.
By minor ad2ustment in fre"uency of the generator, make the speed of
rotation of the pointer in the synchroscope as slower as possible in the >astF direction.
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4.
$lose the generator breaker when the synchroscope pointer is moving
slowly in the >astF direction and reaches # F clock position. t this instant synchronising permissiveF lamp also will glow watch for GB close lamp indication. *.
s soon as the unit is synchronised, watch all parameters and pickup a
load of 5 1.
2.3
.
OPERATION TO BE CARRIED SYNCHRONISING THE GENERATOR.
OUT
AFTER
Get con:rmation about the proper position of semaphore indicator of GB and also !F indication at breaker local from SD$6 normal.
#.
bserve the following parameters and ensure that they are normal. ctive power &1, 6eactive -ower &I6, Generator terminal voltage &in all the phase, stator current &in all the three phases, power factor, rotor voltage, rotor current, stator copper 8 =ron temperature, rotor winding temperature, generator bearing metal temperature, generator bearing vibration, cold gas temperature, hot gas temperature, seal oil pressure and seal oil temperature.
'.
Ensure proper functioning of the Energy meter, 1 and I6 recorders.
9.
$heck at G6- and reset the relays #4/95G, '4G, '4G#, '#G, and '#G# condition.
;.
$heck SE- for any alarm and reset them.
7.
$heck up and ensure the healthy conditions of 0-S, eCcitation transformer etc.
4.
To avail normal incomer supply to 7.7 (I unit buses, at about 95 1 load carry out the following operationsJ a.
Get concurrence from -/0$B.
b.
Ensure from nneCe operator that the normal incomers to unit buses 8 B are relay for taking into service and are racked in.
c.
-ut the selector switch in T=E to 0!=T position.
d.
bserve the voltmeter and double fre"uency meter at G$-.
e.
=f there is di@erence in the voltage make them e"ual by ad2usting eCcitation voltage of the generator. &=ncrease/decrease -Bs of uto
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channel. 1atch for the synchronising permissiveF lamp indication and then close the !ormal =ncomer breaker. f.
bserve the tripping of the Tie breaker on auto along with the annunciation <7.7 (I Tie breaker to unit busA uto trip? at G$-.
g.
!ormalise the control switch of the tie breaker by giving a trip impulse.
h. i.
-ut the selector switch in to T=E in 0T position. Ensure proper functioning of the Energy meter 8 1 meter of the !ormal =ncomer breaker.
2.
To avail !ormal supply to 7.7 (I unit busAB repeat the steps O to &2 for busAB.
k.
ES- :elds may be taken after the withdrawal of all the oil burners.
2.4 GENERATOR OPERATIONS AND SUPERVISION 01 NORMA OPERATION OF GENERATOR .
The supervision over the control and measuring instruments pertaining to the panels of the operating generator constitute the duty of the operation Engineer.
#.
fter the unit is synchronised with the grid, the rate at which the active load be increased depends upon the regime of the turbine.
'.
The readings of the control and measuring instruments of generator desk and panel should be taken every hour.
9.
%ydrogen purity is being indicated continuously by means of the purity meter at G$- and at the local panel. $hemical lab sta@ in each shift for chemical analysis is collecting hydrogen sample. The minimum of the above three readings should be taken into account for hydrogen purity. =t should be above )*+, the purity may be maintained at about )*+. 1hen the purity falls below the permissible value, the pressure of gas inside the generator is to be reduced &by 5. (g/$m # to 5.# (g/$m # by scavenging the gas to the atmosphere and then the pressure to be raised to original value by charging fresh hydrogen.
;.
1eekly report from main chemical lab will indicate the "uantity of moisture present in the hydrogen. This should be less than ) gm/cm'.
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7.
The reactive load on the generator should be controlled by ad2usting the eCcitation voltage.
4.
The following things are to be checked during local check up. a.
The slip rings and brushes are to be inspected for any sparking. The sparking in the brushes may be caused by damage to the brushes, vibration, and seiNing of the brushes in the frames of the brush holder, defective :tting of brushes or due to incorrect contact pressure of the brushes. =ncreasing the contact pressure on either side of the brush can reduce sparking. 1hen the sparking could not be controlled, it has to be reduced by reducing the rotor current i.e. by reducing the reactive power and if necessary by reducing the active power also.
b.
The normal running of the vapour eCtractor in the seal oil system is to be ensured. The drain line of vapour eCtractor to be opened in each shift by the local operator to drain the water/oil. => water is present in the drain, Turbine sta@ is to be informed for operating the centrifuge.
c.
Seal oil drain lines view glasses are to be checked for absence of foaming. %ydrogen leak is to be suspected in case of foaming.
d.
Seal oil pressure at seals and the seal oil temperatures are to be checked and the values should be normal.
e.
=n the SES room the healthiness of :eld breaker trip coil, the charged condition of the >B closing springs and the healthiness of the converter bridges are to be ensured.
f.
=n the .$. system the following are to be ensured. i
The under voltage relay is in reset condition.
ii
The charging current should be normal.
iii
The bus voltage should be normal.
iv
There should be no persisting alarms.
v
%ealthiness of the annunciation window lamps by operating the Hamp TestF push button.
g.
onitor the %# gas pressure 8purity.
h.
onitor the S1S 3ow 8conductivity.
i.
onitor the SS
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i
seal oil pressure at seals.
ii
delta pressure.
iii
3ow of oil at TE 8EE.
!-!-!-!-!-!-!-!-!-!-!-! !-!-!-!-!-!-!-!-!-!
