at
NAME:Pravin biswakarma JALPAIGURI GOVT. ENGG. COLLEGE ELECTRICAL ENGG. DEPARTMENT. DATE OF TRAINING: From 13th June,14 to 03th July,14
VOCATIONAL TRAINING PROJECT REPORT ON MEJIA THERMAL POER !TATION "M.T.P.!#$DAMODAR VALLE% CORPORATION"D.V.C#
A&OUT M.T.P.! Mejia Thermal Power Station is locte! t Durlo"#ur, Dist: $n%ur, &' %m (rom Dur)#ur city in *est $en)l+ ommissione! on 1--', .T/ is the lr)est therml #oer #lnt, in terms o( electricity )enertin) c#city in the stte o( *est $en)l s ell s mon) other D2 #oer #lnts+
P'w(r P)ant: .ei Therml /oer ttion hs n instlle! c#city o( &340 .*+ The #lnt hs units un!er its o#ertion+ The in!i"i!ul units h"e the )enertin) c#cities s (ollos: Unit N'.
G(n(ratin* Ca+a,it-
C'mmissi'n( 'n
561
&10 .*
1--'
56&
&10 .*
1--
563
&10 .*
1---
564
&10 .*
&007
567
&70 .*
&00
56'
&70 .*
568
700 .*
&010
56
700 .*
&010
&00-
5nits 1 to ' re collecti"ely nme! s MTP!/+0as(1, hile the e9tension o( 5nits 8 is clle! MTP!/+0as( 2 + All the units
h"e ;oilers, tur;ines n! )enertors mnu(cture! ;y $hrt
$
5$JET OF TRAINING: T
/=AE OF TRAINING:
DA.ODAR 2A==E@ OR/ORATION .ei Therml /oer ttion /+O:.T/,Dist:$n%ur8&&13,*est $en)l P0'n(:34251/242231
6A7/
34251/282241
ENGINEER 5NDER *De#uty hie( En))+ Elec? &+ .r+ /+B Du;ey >Trinin) A!"isor? DURATION OF TRAINING: 13T< J5NE,&014 to 03T< J5=@,&014
DA.ODAR 2A==E@ OR/ORATION
.ei Therml /oer ttion
/+O:.T/,Dist:$n%ur8&&13,*est $en)l 34251/282241
P0'n(:34251/242231
6A7/
No+.TC/=C2oc+Tr)+C2ol+IIC1'& Dte!:&-th .rch&014 TO WHOM IT MAY CONCERN
This is to certi(y tht .r+/r"in $is%rm, stu!ent o( electricl en)ineerin) o( Jl#i)uri Go"ernment En)ineerin) olle)e, Jl#i)uri83710&>*+$? un!ertoo% "octionl trinin) t .ei Therml /oer ttion, D2, (or the #erio! o( &1>Tenty One? !ys +e+( 13+0'+&014 un!er Electricl De#t+, .T/+ Durin) his trinin) he hs ;een (oun! sincere, hr! or%in) n! ell !isci#line!+
+++++++++++++++
++++++++++++++++++++++++++ "!0ri &i0a-ak D9tta#
hie( En)ineer >Elect+? .T/, D2
The Dy
ACNOW!EDGEMENT Any #roect is the (ruit(ul outcome o( the hr! or% o( mny+ Throu)h this !ocument e oul! li%et' (+r(ss '9r *ratit9( t'wars t0's( w0' s9++'rt( 9s in makin* 9s an '9t,'m( ;r'm 9s.
Firstly, e oul! li%e to thn% !0ri. &i0a-ak 9tta>De#uty hie( En))+ Elec+?+ Trinin) A!"isor? ho )ui!e! us in ech n! e"ery ste# till our com#letion o( our trinin)+ thn%(ul them (or #ool theiro(continue! )ui!nce*e n!re su##ort ithtotheir "st %nole!)e, hich s essentil (or the com#letion o( this #roect+ Alon) the y , e ere lso ;ly su##orte! n! )ui!e! ;y sts o( the "rious !e#rtments+ An! li%e e mentione!, the hel# is e"en more cre!i;le, consi!erin) tht the or%lo! o( the st s immense+
*e oul! lso li%e to thn% our (rien!s n! (mily (or #ro"i!in) encour)ement n! morl su##ort t e"ery ste#+ *e reco)nise e"ery;o!ys hel#in) hn!+
CONTENTS = N O 1
TOPIC INTRODUCTION AND HI!TOR%
&
OVERVIE O6 A POER PLANT
3
ELECTRICAL !%!TEM a"
GENERATOR # AU$I!IRIES 1+ $AI /RINI/=E ONTR5TION &+ EITATION @TE. 3+ A2R 4+ OO=ING @TE. 7+ /ROTETION @TE. '+ GENERATOR .ETERING INT5.ENTATION 8+ E=ETRIA= /ROTETION AND AFET@ INTER=OB
%" O&ER&IEW OF GT' UT' UAT'UST' ST' SAT'SST' NGT ("
SWITCHYARD 1+2ARIO5 O./ONENT &+/ROTETION
)"
STATION GROUNDING SYSTEM
e"
MOTORS
*"
DC SYSTEM
*#
DG SET
INTRODUCTION # HISTORY D2, le)cy to the #eo#le o( In!i, emer)e! s culmintion o( ttem#ts m!e o"er hole century to control the il! n! errtic Dmo!r ri"er+ The ri"er s#ns o"er n re o( &7,000 %m& co"erin) the sttes o( $ihr >no Jhr%hn!? *est $en)l+ Dmo!r 2lley or#ortion s est;lishe! on 8th July 1-4+It is one o( the most re#utte com#ny in the estern one o( In!i+ D2 is est;lishe! on Dmo!r ri"er+ It lso consists o( the Dur)#ur Therml /oer /lnt in Dur)#ur+ The hy!el #roect in .ython is one o( the most Hourishin) #rt o( D2+ The .T/>.ei Therml /oer ttion? un!er D2 is one o( the lr)est therml #oer #lnt in *est $en)l+ It is one o( the (our therml #oer sttions o( D2 in the sttes o( *est $en)l+ The totl #oer #lnt cm#us re is surroun!e! ;y ;oun!ry lls n! is ;siclly !i"i!e! into to mor #rts, rst #oer #lnt re itsel( n! secon! is the colony re (or the resi!ence n! other (cilities (or .T/s em#loyees+
!ALIENT 6EATURE! =oction: .ei in $n%ur District in *est $en)l+ Instlle! #city: >&104 .*K&70& .* K 700& .*?L&340.* ol source: $+++= n! E++=, lso im#orte! (rom In!onesi Fuel Muntity:1&' T/<>(or unit 1 to 4 only? 170 T/<>(or unit 7 n! ' only? &8& T/< >(or unit8 only?
(or unit 1 to '? &8-m >(or #hse II? *ter source: DA.ODAR RI2ER $eneciry tte: *ET $ENGA=, J
OVERVIE O6 POER PLANT OPERATION A #oer #lnt is ;siclly n ener)y con"ersion mechnism+ Therml #oer #lnts o#erte on mo!ie! Rn%in ycle ith rehetin) n! su#erhetin)+ In essence , it is mo!ie! (rom o( the ;sic stem cycle to increse the cycle ePciency+ ol is ;urnt in ;oiler, hich con"erts ter into stem+ The stem is e9#n!e! in tur;ine, hich #ro!uces mechnicl #oer !ri"in) the lterntor cou#le! to the tur;ine+ The or%in) o( the #oer is !i"i!e! into (our min circuits:
Fuel n! sh circuit+ Air n! Fuel )s circuit+ Fee! ter n! stem circuit+ oolin) ter circuit+
THE ENERG% CONVER!ION
hemicl ener)y to het ener)y In $oiler
6LUE
ATER 6UEL AIR
THERMAL POER PLANT
A!H
ELECTRIC IT%
ENERG@ F=O* DIAGRA. OF DIFFERENT /ART :
ENERG@ >OA=?
TEA.?
.ET5R$INE?
.E
E=ETRIA=
OVER VIE O6 A POER PLANT
VARIOU! COMPONENT! O6 A POER PALNT: DEAERATOR: The con!ense! ter (rom the con!enser is t%en to !eertor here the ter is m!e (ree (rom o9y)en minly i+e+ (ree (rom ir+ The !eertor is !irect het e9chn)er ;ecuse the stem (rom I/T is s#rye! to the con!ense! ter (rom the ;ottom n! the
ter is s#rye! (rom the #rt (rom o( the !eertor+ o9yction i+e+ remo"l o( to# o9y)en the ter+ This results in !e
&OILER 6EED PUMP! "&6Ps#: The outlet o( the !eertor is connecte! to ;oiler (ee! #um#s, there re three $F/ in ro out o( hich to re in runnin) con!ition n! one is t stn!;y,in unit 61 to ' ll $F/ re .D$F/,consumes hi)hest #oer in the #lnt 4+'.* in (ull lo! n! unit68 n! one o( these is .D$F/> motor !ri"en?, n! other to re TD$F/>stem !ri"en?+.D$F/ consumes the hi)hest #oer in this #lnt i+e+ 10.*+ .D$F/ is use! only t the strtin) time (or its hu)e #oer consum#tion+ HIGH PRE!!URE HEATER: The
I/T n!
$*>$oiler circultin) ter #um#?+ It is lso houses the stem tht is (orme! in the ;oiler+ *ter store! in the !rum comes !on to the to# o( the ;oiler n! (orms ter rin) S hich is then inserte! into the ;oiler throu)h the ' ter lls+ *ter lls re ;siclly tu;es lon) the lls o( the (urnce, it is here here the ter is con"erte! into stem t 130Q n! then the #ro!uce! stem is t%en ;c% to the ;oiler !rum+ The !rum hs #ro#eller tht rottes t hi)h s#ee! n! m%es the stem n! ter se#rte! !ue to centri(u)l (orce+ The #ressure o( ;oiler !rum is 1-& %)CsM+ cm n! must ;e lys mintine!+ *ter in the !rum comes (rom (ee! control sttion "i economiser+
$oiler is the min sectiono(here 6URNACE AND &OILER:/ stem is #ro!uce! ;y col com;ustion+ $oiler consists ;oilerthe !rum, ter lls, in! ;o9, heters+ The ;oiler hs ele"tions nme! s A $DEFG<+ ol is inserte! into the ;oiler (rom A$DEFG<+ There is mills (or (ee!in) the #ul"erie! col to the (urnce+ Ech mill hs 4 #i#e (or rin) in the (our corners o( (urnce+ Furnce is !i"i!e! into to #rts nme! s rst #ss n! secon! #ss+ The com;ustion
t%es #lce in the rst #ss n! the hetin) o( stem throu)h < t%es #lce in the secon! #ss+
!UPER HEATER: The im#ortnt #oint is to ;e lys %e#t in min! tht ll the heters tht re use! in therml #oer #lnt re mechnicl
ty#e heters i+e+ het e9chn)e! #henomen hets one me!ium ;y e9chn)in) het (rom nother hotter me!ium+ u#er heters re ctully sus#en!e! #i#es in the secon! #ss section o( the ;oiler, the Hue )s h"in) "ery hi)h tem#erture hets the stem tht comes (rom the !rum ;e(ore they hit the tur;ines to tem#erture u# to 740Q+ The #ressure o( stem is %e#t constnt hen #ssin) throu)h su#er heter+ The min conce#t ;ehin! m%in) the stem su#er hete! is to m%e the stem ;solutely moisture (ree ;e(ore they hit the tur;ine ;ecuse moisture content o( stem ill !m)e the ;l!es o( tur;ine ;y corrosion+
TUR&INE !ECTION: The tur;ine section consists o( three #rts nme! s Interme!ite #ressure tur;ine?,=/T>=o #ressure tur;ine?+ The su#erhete! stem (rom the u#erheter enters the R
con!enser hs three e9trction #um#s %non s on!enste E9trction /um#s >E/A, E/$, E/?+ These #um#s crete ne)ti"e #ressure i+e+ "cuum in the con!enser (or ;etter suction o( the con!enste+ The outlet o( the E/ is connecte! to lo #ressure heter>=/
o"erll unit+
6LUE GA! PATH : AIR PREHEATER: The Hue )s #ro!uce! s result o( com;ustion o( (ossil (uel in the (urnce is t%en to the ir #re heter+ The ir #re heter is use! to het u# the tmos#heric ir to m%e hot ir use! (or com;ustion n! trns#ort o( col !ust (rom mill to (urnce hich clle! secon!ry ir+ This heter hs uniMue #rocess o( hetin), it hs sh(t ttche! to rottin) heel ty#e structure>li%e tur;ine ;ut rrn)ement ;l!es re !ierent?+ Atmos#heric ir re suc%e! ;y FD (ns #sses throu)h one si!e o( the rottin) sh(t n! the hot Hue )s #sses throu)h nother si!e+ This y het o( the Hue )s )ets trns(erre! to the tmos#heric ir n! )ets hete!+ There re to ir #re heters (or ech unit nme! s A<A n! A<$+ ELECTRO!TATIC PRECIPITATOR "E!P#:/
5n!er )o"ernment rules n! re)ultion (or in!ustril #ollution control, E/ is must to ech n! e"ery in!ustry hich !els hi)h sh s resi!in)+ An electrosttic #reci#ittor is lr)e , in!ustril emission control unit+ It is use! in in!ustries li%e therml #oer #lnt, cement, ##er, chemicls, metllur)icl in!ustries etc, hich emit #rticles+ In the therml #oer #lnt it is !esi)ne! to tr# n! remo"e sh #rticle (rom the e9hust )s o( ;oiler+ len )s, u# to --+-U clener thn hen it enter is then #sses out o( the #reci#ittors+ collectin) electro!e
e%est
el!
Emittin) electro!e OR
An E/ is chm;er in hich Hue )s (rom the (urnce is (orce! into FD (ns+ Electrosttic #reci#ittion is #hysicl #rocess ;y hich #rticles sus#en!e! in )s strem re chr)e! electriclly, n! un!er the inHuence! o( electric el! re se#rte! (rom the )s strem+ The #reci#ittion system consists o( ne)ti"ely chr)e! hi)h "olt)e !ischr)e! electro!e ire sus#en!e! mi!st #ositi"ely chr)e! collectin) electro!e sur(ces+ At "ery hi)h D "olt)e o( the or!er o( &0B237 B2, coron !ischr)e! occurs close to the ne)ti"e electro!e, settin) u# n electric el! ;eteen the emitter n! the chr)e! sur(ce+ *hen the #rticle l!en )s #sses throu)h the E/ el!s, the )s close to the ne)ti"e electro!e is thus ionise! u#on #ssin) throu)h the coron + As the ne)ti"e ions n! electrons mi)rte
tor!s the chr)e! sur(ce, they in turn chr)e the #ssin) #rticle+ The electrosttic el! then !rs the #rticles to the collector sur(ce here they re !e#osite!+ /erio!iclly, the collecte! #rticles re remo"e! (rom the collectin) sur(ce ;y r##in) or "i;rtin) the collector to !islo!)e the #rticles+ The !islo!)e! #rticles !ro# ;elo the electricl tretment one n! re collecte! throu)h ho##ers (or ultimte !is#osl+ The mor com#onents tht ccom#lishe! ;o"e cti"ities in E/ re s (ollos:
In #rctice the E/ shll consists o( se"erl such el!s in series in the !irection o( )s Ho+ There my ;e to or more #rllel #sses o( such series com;intion to meet the !esire le"el o( !ust remo"l (rom the Hue )s +
DRA6T 6AN!: There re ;siclly three ty#es o( (ns in therml #oer #lnt+ i+ ii+ iii+
IND5ED DRAFT >ID FAN? FORED DRAFT FAN >FA FAN? /RI.AR@ AIR FAN >/A FAN?
INDUCED DRA6T 6AN= ID 6AN:
This (n is use! to crete ne)ti"e #ressure in the (urnce i+e+ (urnce #ressure is loer thn tmos#heric #ressure, s result o( hich re ;lls insi!e the (urnce cn not come out o( the (urnce+ID (ns lso !ri"es the Hue )s throu)h out its #th n! nlly eects it out o( chimney+ It suc%s ir (rom the (urnce n! eects it to the tmos#here+ .echniclly ID (n is cou#le! ith one 3#h synchronous ty#e motor+ It is the only synchronous motor in the #oer #lnt ;ecuse it )i"es more ccurte control to its s#ee! ;y 2C( metho! (or mintinin) ne)ti"e #ressure s controllin) o( ne)ti"e #ressure is the most "itl (ctor in ny therml #oer #lnt+ There re to ID (n (or ech unit+ 6ORCED DRA6T 6AN:/ 5nli%e ID (n, the FD (n is ment (or cretin) #ositi"e #ressure in the (urnce n! lso su##lies ir (rom /A (n n! secon!ry ir (or com;ustion+ The FD (n t%es ir (rom tmos#here n! e9#el it to the #lnt >i+e+ in the (urnce, in! ;o9 etc?+.echniclly FD (n consist o( one 3#h in!uction motor, min ;erin) >nti(riction ;erin)? n! lu;e oil system+ PRIMAR% AIR 6AN=PA 6AN: /rimry ir (n is use! (or mi9in) o(
col! ir o( FD (n outlet ith hot ir o( ir #reheter outlet+ The min (unction o( this is to trns#ort #ul"erise! col (rom the mill to (urnce+ .i9in) o( hot ir n! col! ir is necessry ;ecuse it is nee!e! to mintin the tem#erture o( the #ul"erise! col (rom 0Q to -0Q (or ;etter trns#ort o( col n! ;etter com;ustion in the (urnce+ .echniclly the construction o( /A (n is sme s FD (n+
T0( E)(,tri,a) !-st(m:/ The electricl system ;siclly strts t the tur;o lterntor n! throu)h the GT>)enertor trns(ormer? to the sitchyr! n! nlly to the trnsmission lines+ In ;eteen the netor% consists o( mny isoltors, circuit ;re%ers, T, /T n! other mechnisms+ At .T/ the tur;o lterntor )enertes "olt)e o( 17+87B2>5nit61C&C3C4?,1'+'B2>5nit67C'?, &1 B2> /hse II?+ The GTs ste#s this u# to &&0 B2>400B2 (or /hse II?+ The trnsmission is to Blynesri ,$urn#ur,$oror,Dur)#ur n! (or #hse IIthe trnsmission is to .ython, DT/, Jmshe!#ur+
There(ore the electricl system is : For Unit+, to - . G(n(rat'r GT Transmissi'n Lin(s For Unit+/ an) 0. G(n(rat'r GT Transmissi'n Lin(s
223
533
A#rt (rom these, the electricl system is intrictely intertine! ith the entire #lnt, consi!erin) tht the entire #rotection n! control is someho !one electriclly+
tor
GENERATOR &A!IC PRINCIPLE AND CON!TRUCTION: Prin,i+)(: Genertor con"erts mechnicl #oer into electricl (orm n! (ee!s it into the #oer system netor% + The or%in) #rinci#le ;ehin! the o#ertion o( )enertor is Fr!ys =s o( electrom)netic in!uction+ The in!uce! lterntin) "olt)e in )enertor cn ;e e9#resse! s
EL4+44(TW 2olt *here, EL 2olt)e in!uce! in "olt+ (L(reMuency o( rottion in <+ TLNo+ o( turns WL(lu9 #er #ole in *;+ The (reMuency o( the lterntin) "olt)e is )i"en ;y the (olloin) eMution (L/NsC& here, (L(reM in <+ /Lno+ o( #oles NsLre"olutionCsec+ C'm+'n(nts '; G(n(rat'r: The min com#onents o( Genertor re:
&+Rotor
3+$erin) n! lu;riction !uct 7+E9cittion system ssem;ly 8+oolin) system
ttor:
4+Terminl $ushin) n! $us '+ li# rin) n! $rush )er + elin) system
The sttor em;o!ies the core, sttor in!in) n! hy!ro)en coolers n! #ro"i!es )s ti)ht enclosure (or hy!ro)en )s+ It com#rises o( n inner n! n outer (rme+ The outer (rme is ri)i! (;ricte! structure o( el!e! steel #ltes c#;le o( ;erin) the #ressure !ue to minor e9#losion o(
TUR&O GENERATOR
E9chn)es het in the
The rotor (orms the rottin) m)netic #oles o( the )enertor+ This is cylin!ricl ty#e n! constructe! (orm cst hromium , Nic%el, .oly;!enum n! 2n!ium steel throu)h se"erl st)es o( mchinin)+ lots re mchine! on the outer sur(ce to incor#orte in!in)s + e+)+ micnite? is use! (or linin) the slots+ *ith increse in )enertor c#city rotor in!in)s use! to crry (irly hi)h !irect current (or suPcient m)netic stren)th+ This hi)her lo!in) cuses consi!er;le mount o( het loss n! lr)e rotors incor#orte com;intion o( hollo con!uctors ith slots or holes rrn)e! to #ro"i!e (or circultion o( the coolin) )s throu)h the ctul con!uctors ;y )# #ic% u# metho! +Due to "ery hi)h rottionl s#ee! centri(u)l (orce tries to li(t the in!in) out o( the slots+ o they re contine! in #ro#er #lce ;y !urlumin e!)es+ The en! turns outsi!e the slots re co"ere! ;y nonm)netic steel retinin) en! rin)s n! re secure! to the rotor ;o!y+ The en! in!in) re insulte! (rom retinin) rin)s ith the hel# o( )lss e#o9y mol!e! se)ments+ The retinin) rin) is sin)le #iece (or)in) hich #rotects the rotor en! in!in) (rom hi)h centri(u)l (orce+ E7CITATION !%!TEM O6 TUR&O GENERATOR:/
The #ur#ose o( e9cittion system is to continuously #ro"i!e the ##ro#rite mount o( D+ el! current to the )enertor el! in!in)+ The e9cittion system is reMuire! to (unction reli;ly un!er the (olloin) con!itions o( the )enertor n! the system to hich it is connecte! + i?Durin) strt u# o( the )enertor+ ii?Durin) ste!y stte o#ertin) con!ition+ iii?At the time o( trnsient !istur;nces >!ue to su!!en ##lictions or remo"l o( lo!?+ i"?Durin) #rolon)e! system !istur;nces+
The sim#lest cse is tht o( !urin) strt u# hen the )enertor is runnin) t rte! s#ee! ith )enertor circuit ;re%er o#en>rmture o#en circuite!?+ The terminl "olt)e ill increse ith the increse in el! current+ Amount o( el! current reMuire! ill ;e (unction o( only the terminl "olt)e+ $ecuse o( m)netic sturtion more el! current ill ;e reMuire! to #ro!uce n increment o( rmture "olt)e t hi)h "olt)e thn t lo "olt)e+ This ill ;e )o"erne! ;y o#en circuit chrcteristics>O++? o( the mchine+ A(ter the closin) o( )enertor circuit ;re%er the mchine is connecte! to the system n! o#ertes in #rllel ith other mchines connecte! to the system+ The mount o( el! current reMuire! ill ;e (unction o( the terminl "olt)e s ;e(ore n! lso the lo! current n! the #oer (ctor+ This ill ;e )o"erne! ;y the 2cur"es o( the mchine+ 5nli%e the #re"ious cse i( the )enertor is connecte! to lr)e system chn)e in e9cittion current controls the recti"e #oer>2AR? n! the #oer (ctor only ith "ery minor inHuence o( the terminl "olt)e+ .ore se"ere !uty the e9cittion system reMuires to #er(orm u#on is !urin) system !istur;nces+ At the time o( trnsient !istur;nces the )enertor "olt)e my !i# or rise momentrily+ The e9cittion system must res#onse (st to correct this Muic%ly n! st;ly+ Durin) #rolon)e! !istur;nces>hich my lst (rom se"erl secon!s to se"erl minutes? the e9cittion system my reMuire to o#erte t it m9imum or ceilin) out#ut+ Thus #ro#erly !esi)ne! e9cittion system shoul! #ermit ?lose control o( the )enertor "olt)e to mtch closely to the system "olt)e ;e(ore synchronition+ ;?lose control o( 2AR (ter synchronition o( the mchine, ithout loss o( st;ility or o"erhetin) o( the el! system+ c?O#ertion o( the system t its m9imum or ceilin) t the time o( !istur;nces in the system+ DEVELOPEMENT O6 E7CITATION !%!TEM: *ith increse in )enertor c#city n! com#le9ity o( interconnection in #oer system, im#ro"e! techniMues in )enertor e9cittion h"e ;een !e"elo#e! ith the im to chie"e hi)her c#city, i!el rte o( res#onse, sim#licity, reli;ility, ccurcy, sensiti"ity etc+ In the erlier !esi)ns se"erl conce#ts )o"ern the mority o( the e9cittion system, such s ? E9citers ere commuttor ty#e n! sel( e9cite!+ ;? E9citers ere sh(t !ri"en n! motor !ri"en rottin) mchines+
c? 2olt)e re)ultors inclu!e! m)netic or rottin) m#liers or com;intion o( ;oth+ !? .nul control s ;y mens o( rheostt+ Ne9t )enertion o( e9cittion system intro!uce! neer conce#ts+ ome o( hich ere ? 5se o( semicon!uctors (or rectiction+ ;? A>utomtic? "olt)e re)ultor ith trnsistor #rem#liers n! thyristors + c? Ne conce#ts o( mnul control+ !? Elimintion o( commuttors+ e? Ne #hysicl rrn)ements, (? Ne mintennces #roce!ures + /resent !y e9cittion system h"e ;een #romote! ;y ? #city to meet "ery hi)h "lues o( e9cittion suit;le (or unit c#cities s hi)h s 700.* or e"en more+ ;? 5se o(
The ty#es o( e9cittion system re i? D e9cittion ii? ttic e9cittion iii? $rushless e9cittion In .T/ r;on $rush E9cittion is use! in 5nit61 to 4 n! in 5nit67to ;rushless e9cittion system is use!+ &RU!HLE!! E7CITATION:/ u##ly o( hi)h current ;y mens o( cr;on ;rush in"ol"es consi!er;le o#ertionl n! mintennce #ro;lems+ These #ro;lems re eliminte! in ;rushless e9cittion system hich consists o( A min e9citer , /.G, rottin) noncontrolle! rectiers, ll mounte! on the T+G sh(t n! sttic A2R+ Fiel! o( the /.G hich is #ermnent slient #ole m)net rottes lon) ith the )enertor sh(t
n! )enertes #ermnent "olt)e >usully 400 " t 400 < (reM+? t the sttor in!in)s+ These out#uts (rom the /.G is connecte! to the thyristors locte! in the A2R #nel+ The controlle! D out#ut (rom the A2R #nel is connecte! to the sttionry el! o( the min e9citer+ The out#ut (rom the rottin) rmture is connecte! to the !io!es #lce! lon) ith the rottin) t the sme s#ee! tht o( the rottin) rmture o( the e9citer n! )enertor el! in!in)+ Thus there is no Ho o( current ;eteen ny mo"in) #rt n! sttionry #rt n! hence they use o( ;rush )er is eliminte!+ The !io!es re rrn)e! on rectier heels in three #hse con)urtion +These re #rotecte! ith (use n! R netor%+ Durin) o#ertion the (uses re monitore! ith the hel# o( stro;osco#e+ The entire rrn)ement is totlly enclose! n! the hot ir is coole! in to or more cooler rrn)e! lon)si!e the e9citer+ A#rt (rom the (use monitorin) unit, other (etures #ro"i!e! in ;rushless e9cittion system re )roun! (ult !etection,el! current mesurements etc+ AUTOMATIC VOLTAGE REGULATOR"AVR#:/
Automtic "olt)e re)ultor >A2R? is the hert o( e9cittion system o( )enertor+ No !ys the A2R uses semicon!uctor elements to chie"e hi)h reli;ility ith "ery (st res#onse+ It hs to in!e#en!ent chnnels, the Auto chnnel ith close! loo# "olt)e re)ultion n! the .nul chnnel ith o#en loo# re)ultion+ The to chnnels o( the "olt)e re)ultor re !esi)ne! (or o#ertion either on i? sttion u9iliry A #oer su##ly n! ii? #oer su##ly (rom )enertor terminl or #ilot e9citer s the cse my ;e+ $oth the uto n! mnul chnnels consist o( #oer #rt n! control #rt+ ome o( the slient (etures o( A2R re : ? #;ility o( mintinin) constnt terminl "olt)e o"er i!e o#ertin) rn)e n! mintinin) #ro#er shre o( recti"e lo! mon) the #rllel runnin) mchines+ ;? /ro"ision (or risin) the e9cittion le"el Muic%ly >el! (orcin) ? in cse o( (ult or "olt)e !i# to increse the trnsient st;ility limit o( the system+ c? In cor#ortion o( suit;le circuitry to m%e the re(erence "olt)e s liner (unction o( (reMuency or tur;o )enertor u# to the e!)e
(reMuency cn ;e set !e#en!in) on the reMuirement n! constnt re(erence "olt)e ;eyon! e!)e (reMuency+ !? /ro"ision o( utomtic (ollo u# circuit to su#er"ise n! mtch the rin) n)les o( the #ulses in utochnnel n! mnul chnnel so tht the !istur;nce on the )enertor terminl is minimum !urin) trns(er (rom uto re)ultion to mnul re)ultion+ e? /ro"ision o( sttor current limiter , rotor current limiter n! rotor n)le limiter circuits (or o#timum le!in) recti"e c#;ilities o( theutilistion )enertor+o( the l))in) n! (? /ro"ision o( utomtic trns(ormer (rom uto re)ultion to mnul re)ultion in cse o( mesurin) /T (use (ilure or some internl (ults in the uto chnnel+ )? Fcility (or remote control o( "olt)e ;oth in uto n! mnul chnnel+ G(n(rat'r C'')in* an !(a)in* !-st(m:/ !TATOR ATER !%!TEM • •
• • • • •
ttor tercoolin) is close! loo# system There re to (ull c#city sin)le st)e centri(u)l #um#s ith chn)e o"er (cility 3/h+4172 A+ motors !ri"e the #um#s The sttor ter cooler is shell n! tu;e ty#e het e9chn)er D. ter Hos throu)h shell There re to mechnicl lters n! one m)netic lter .echnicl lters re o( ire mesh ty#e .)netic lter is h"in) #ermnent m)net
GA! !%!TEM
Genertor )s system constitutes o( hy!ro)en )s use! to cool the rotor n! certin #rts o( sttor+
C'')in* ;ans /ro#eller ty#e coolin) (ns t ;oth the en!s o( rotor re #ro"i!e! (or (orce! circultion o( ir coole! mchines ?insi!e the )enertor+ Fn hu;s re m!e (rom lloy steel (or)oin) n! re shrun% tte! on the rotor sh(t+ The lloy steel cst (n ;l!es re 9e! on the (n hu; throu)hout its #eri#hery ith the hel# o( stren)th lloy steel nonm)netic conicl #ins+ These (n ;l!es re esily remo";le (rom the hu;+ Fn shiel!s re #ro"i!e! to )ui!e the )s Ho+ Fn shiel!s re 9e! to the en! shiel!s+
!PECI6ICATION O6 TUR&O GENERATOR:/ For 1nit+, to 2
B*:&10.* #+(:0+7 l) B2A:&48,000 ttor "olt)e:17+87 B2 ttor m#ere:-070 A Rotor "olt)e:310 2 Rotor m#ere:&700A R#m:3000 FreMuency:70 < onnection: @ @ oolnt: *ter G? Insultion clss: F #eciction: I:74&& IE:34 For 1nit+3 an) B*:&70.* #+(:0+7 l)
B2A:&-4100 ttor "olt)e:1'+7 B2 ttor m#ere:10&-1 A Rotor "olt)e:&-&2 Rotor m#ere:&3-7A R#m:3000 FreMuency:70 < onnection: @ @ oolnt: G? Insultion clss: F #eciction: I:74&& IE:34 For Unit+/ an) 0
B*:700 .* #+(:0+7 l) B2A:7,000 ttor "olt)e:&1 B2 ttor m#ere:1',&00 A Rotor "olt)e:340 2 Rotor m#ere:4040 A R#m:3000 FreMuency:70 < onnection: @ @ oolnt: *ter G? Insultion clss: F #eciction: I:74&& IE:34 !PECI6ICATION O6 PILOT > MAIN E7CITER"Unit?@ > 8# Main E,it(r Pi)'t E,it(r A##rent /oer: 37B2A
Acti"e /oer: urrent: 107A 2olt)e: &&0KC&&2 #ee!: 70C FreeMuency: 400<
1344B* 3&00A 4&02 70C 170<
!PECI6ICATION O6 PMG"Unit? > B#:/ B*:3B2A:'7 2olts:&&0 Am#s:1-7 R#m:3000 /hse:3 oolnt: Air Insultion lss: F onnection: @ @ @ @ @@@@
#eciction: IF34 !PECI6ICATION O6 &RU!HLE!! E7CITER"Unit?> B#:/
B*:380 2olts D:'00 Am#s D:'300 E9cittion 2olts D:108 E9cittion Am#s D:14& R#m:3000 oolnt: Air Insultion lss: F #eciction: IF34 GENERATOR PROTECTION:/
*ith the e"er incresin) sie o( the )enertor cost o( the mchine, the e9#enses (or re#ir n! loss o( ener)y !urin) the out)e o( the mchine re "ery hi)h+ lo!, (reMuency, tem#erture? n! ;eyon! the s#ecie! limits+ uch ;norml runnin) con!ition oul! result in )r!ul !eteriortion n! ultimtely le! to (ilure o( the )enertor+ It my ;e #ossi;le to correct the runnin) o( the )enertor+ It my ;e #ossi;le to correct the runnin) con!ition (ter the #rotecti"e rely )i"es n lrm, there ;y "oi!in) the loss o( re"enue n! !m)e o( the mchine+ In the lter cse , it is necessry to restrict the !m)e o( the mchine n! ssocite circuit to minimum ;y t%in) it out (rom the ser"ice+ PROTECTION UNDER A&NORMAL RUNNING CONDITION!: / ?Ov(r ,9rr(nt +r't(,ti'n: The o"er current #rotection is use! in )enertor #rotection )inst e9ternl (ult s ;c% u# #rotection+ Normlly e9ternl short circuits re clere! ;y #rotection o( the (ulty section n! re not !n)erous to the )enertor+ I( this #rotection (ils the short circuit current contri;ute! ;y the )enertor is normlly hi)her thn the rte! current o( the )enertor n! cuse! o"er hetin) o( the sttor, hence the )enertors re #ro"i!e! ith ;c% u# o"er current #rotection hich is usully !enite time l) o"er current rely+ ;?Ov(r )'a +r't(,ti'n: /ersistent o"er lo! in rotor n! sttor circuit cuse hetin) o( in!in) n! tem#erture rise o( the mchine+ /ermissi;le !urtion o( the sttor n! rotor o"er lo! !e#en!s u#on the clss o( insultion, therml time constnt, coolin) o( the mchine n! is usully recommen!e! ;y the mnu(cturer+ $eyon! these limits the runnin) o( the mchine is not recommen!e! n! o"er lo! #rotection therml relys (e! ;y current trns(ormer or therml sensors re #ro"i!e!+
c?Ov(r v')ta*( +r't(,ti'n: The o"er "olt)e t the )enertor terminls my ;e cuse! ;y su!!en !ro# o( lo! n! A2R ml(unctionin)+ sitchin) sur)es or li)htnin)? my lso cuse o"er "olt)e t the )enertor terminls+ .o!ern hi)h s#ee! "olt)e re)ultors !ust the e9cittion current to t%e cre )inst the hi)h "olt)e !ue to lo! reection+ =i)htnin) rresters connecte! cross the )enertor trns(ormers terminls t%e cre o( the su!!en hi)h "olt)es !ue to e9ternl sur)es+ As such no s#ecil #rotection )inst )enertor hi)h "olt)e my ;e nee!e!+ Further #rotection #ro"i!e! )inst hi)h m)netic Hu9 t%es cre o( !n)erous increse o( "olt)e+ !?Hi*0 9 (nsit-: "olts #er <? ;sis is recommen!e! s #re"enti"e mesure (or #rotection )inst hi)h Hu9 !ensities+ e?Unba)an,( )'ain* +r't(,ti'n: 5n;lnce lo!in) is cuse! ;y sin)le #hse short circuit out si!e the )enertor, o#enin) o( the one o( the contcts o( the )enertor circuit ;re%er sn##in) o( con!uctors in the sitchyr! or e9cessi"e sin)le #hse lo!+ 5n;lnce lo! #ro!uces Y"e #hse seMuence current hich cuse o"er hetin) o( the rotor sur(ce n! mechnicl "i;rtion+ Normlly 10U o( un;lnce is #ermitte! #ro"i!e! #hse current !o not e9cee! the rte! "lues+ For Y "e #hse seMuence currents ;o"e 710U o( rte! "lue !n)erous o"er hetin) o( rotor is cuse! n! #rotection )inst this is n essentil reMuirement+ The rely #ro"i!e! (or this is n in"erse chrcteristic ith !enite minimum time !ely rely connecte! to netor% hich se)re)tes the Y"e seMuence current (rom the #ositi"e n! ero seMuence currents+ The I&t chrcteristics o( the rely is mtche! to the rotor hetin) chrcteristic+ (?L'ss '; (,itati'n +r't(,ti'n: The loss o( e9cittion in synchronous mchine my ;e cuse! ;y tri##in) o( el! circuit ;re%er or trou;le in A2R+ On loss o( e9cittion the )enertor strts !rin)
recti"e #oer (rom the )ri! inste! o( su##lyin) it+ The #oer (ctor o( the )enertor ;ecomes c#citi"e n! s result o( this synchronous runnin) > hi)her sli# (reMuency? o"er hetin) o( the rotor sur(ce t%es #lce+ In cse the )enertors connecte! to the system cn not su##ly this recti"e #oer there ill ;e lr)e "olt)e !ro# in the system le!in) to inst;ility+ The #rotection #ro"i!e! )inst loss o( e9cittion is ;y n oset .ho rely+ Its o#ertin) chrcteristics is so chosen tht !urin) e9tremely lo e9cittion (ults ithin the tri##in) one+ )? L'ss '; +rim( m'v(r +r't(,ti'n: In the e"ent o( loss o( #rime mo"er the )enertor o#ertes s motor n! !ri"es the #rime mo"er itsel(+ In some cses this con!ition coul! ;e "ery hrm(ul s in the cse o( stem tur;ine sets here stem cts s coolnt, mintinin) the tur;ine ;l!es t constnt tem#erture n! the (ilure o( stem results in o"er hetin) !ue to (riction n! in!)e loss ith su;seMuent !istortion o( the tur;ine ;l!e+ This cn ;e sense! ;y #oer rely ith !irectionl chrcteristics n! the mchine cn ;e t%en out o( ;r un!er the con!ition+ $ecuse o( the sme reson continuous "ery lo le"el o( out#ut (rom the therml sets re not #ermissi;le+ The )enertor ;re%er is tri##e! un!er this con!ition ;y the use o( rely mesurin) the electricl #oer out#ut o( the )enertor !esi)ne! to o#erte hen the #oer out#ut (ults ;elo selecte! #reset "lue+ h?P')( s)i+ +r't(,ti'n: A )enertor my loss synchronism ith system ithout losin) the e9cittion+ In this con!ition the mchine my ;e su;ecte! to se"ere mechnicl torMue n! oscilltion ith conseMuent "rition o( current, "olt)e n! #oer (ctor+ I( the n)ulr !is#lcement o( the rotor e9cee!s the st;le limit, the rotor ill sli# #ole #itch+ I( the !istur;nce #ersist the mchine must ;e isolte! (rom the system to #re"ent !m)e to the )enertor n! to minimie #oer system !istur;nce+ The #ole sli##in) #rotection rely o#ertes on the criteri tht the n)le o( the )enertor E.F e9cee!s certin 9e! "lue ith the o#ertion o( the re"erse #oer rely+ The occurrence o( these criteri re counte! n! the mchine is tri##e! out (ter certin num;er o( oscilltions+ These relys re c#;le o( !etectin) the rst #ole sli# con!ition hen sli#, corres#on!in) to the s#ee! o( #ole sli##in) is in the rn)e o( K0+1U to K10U on 70< ;sis+ The #rotection must remin ino#erti"e (or ste!y stte l!in), #oer sitchin) n! correctly clere! system (ult con!ition+
PROTECTION UNDER 6AULT CONDITION:/ a#!tat'r s0'rt ,ir,9it: hort circuits re mon) the (ults hich cuse the he"iest !m)e to the )enertor+ Not only !o they result in therml !m)es such s the el!in) o( the core lmintions n! ;urnin) o( the in!in) ;ut lso result in #ossi;le mechnicl !m)e
li%e !e(ormtion o( the en!s o( the coil+ 2ery (st o#ertin) #rotection is reMuire! , otherise the !m)e my ;e ;eyon! re#ir+ Dierentil #rotections, inter turn short circuit #rotections re the min #rotection )inst short circuits in sttor in!in)+ As ;c% u# #rotection (or the sme (ults, minimum im#e!nce n! o"er current #rotections re use!+ b#Di(r(ntia) +r't(,ti'n: The #rotection is use! (or !etection o( internl (ults in s#ecie! one !ene! ;y the Ts su##lyin) the !ierentil rely+ For n unit connecte! system se#rte !ierentil relys re #ro"i!e! (or )enertor, )enertor trns(ormer n! unit trns(ormer in !!ition to the o"erll !ierentil #rotection+ In or!er to
restrict !m)e "ery hi)h !ierentil rely sensiti"ity is !emn!e! ;ut sensiti"ity is limite! ;y T errors, hi)h inrush current !urin) e9ternl (ult n! trns(ormer t# chn)er "ritions+ ,# Int(r t9rn ;a9)t +r't(,ti'n: Inter turn (ults com#rise o( insultion (ilure ;eteen turns o( the sme in!in) or ;eteen the #rllel in!in) o( the sme #hse hich cn not ;e !etecte! ;y lon)itu!inl !ierentil #rotection+ Inter turn (ults h"e commonly ;een !isre)r!e! on the ;sis tht i( the occur the ill Muic%ly !e"elo# into erth (ults or #hse to #hse (ults hich ill ;e !etecte! ;y the sensiti"e #rotections #ro"i!e! (or these (ults+ *ith this i!e sometimes no s#ecic #rotection (or inter interturn (ult is #ro"i!e!+
consi!erin) the ris% o( se"ere !m)e to the mchine ;e(ore the (ults con"ert into ;o"e ty#es o( (ults inter turn (ult #rotection is recommen!e!, In lr)e mchine s ll the three in!in)s re ;rou)ht out se#rtely it is #ossi;le to em#loy system to trns"erse !ierentil #rotection consistin) o( ;lnce! current rrn)ement ;eteen current trns(ormers connecte! in the line en!s o( the in!in)s in hich current in the #rllel #ths o( the in!in)s re com#re!+ A ;is system is lys use! s it is not #ossi;le to
)urntee in !"nce tht e9ct current shrin) ;eteen in!in)s t%e #lce+ # &a,k/9+ im+(an,( +r't(,ti'n: This #rotection is ;siclly !esi)ne! s ;c% u# #rotection (or the #rt o( the instlltion situte! ;eteen the )enertor n! the )enertor n! unit trns(ormers+ A ;c% u# #rotection in the (orm o( minimum im#e!nce mesurement is use!, in hich the current in!in)s re connecte! to the Ts in the neutrl connection o( the )enertor n! its "olt)e in!in)s throu)h /T to the #hse to #hse terminl "olt)e+ The #ic% u# im#e!nce is set to such "lue tht it is only ener)ise! ;y short circuits in the one s#ecie! ;o"e !oes not res#on! to (ults ;eyon! the trns(ormers+ (# !tat'r (art0 ;a9)t +r't(,ti'n: The erth (ult #rotection is the #rotection o( the )enertor )inst !m)es cuse! ;y the (ilure o( insultion to erth+ /resent #rctice o( )roun!in) the )enertor neutrl is so !esi)ne! tht the erth (ult current is limite! ithin 7 n! 10 A./s+ Fult current ;eyon! this limit my cuse! serious !m)e to the core lmintions+ This le!s to "ery hi)h e!!y current loss ith resultnt hetin) n! meltin) o( the core+ ;# @F stat'r (art0 ;a9)t +r't(,ti'n: In"erse time "olt)e rely connecte! cross the secon!ry o( the hi)h im#e!nce neutrl )roun!in) trns(ormer rely is use! (or #rotection o( roun! -7U o( the sttor in!in) )inst erth (ult+ *#133F stat'r (art0 ;a9)t +r't(,ti'n: erth (ult in the entire sttor circuits re !etecte! ;y selecti"e erth (ult #rotection co"erin) 100U o( the sttor in!in)s+ This 100U EC( rely monitors the hole sttor in!in) ;y mens o( co!e! si)nl current continuously inecte! in the )enertor in!in) throu)h cou#lin)+ 5n!er norml runnin) con!ition the si)nl current Hos only in the stry c#citnces o( the !irectly
connecte! system circuit+ In cse o( n erth (ult , this c#citnce is ;y#sse! n! the monitorin) current hich is !etermine! minly ;y the resistnce to erth increses+ This increse! current "lue n! re#ro!uction o( the si)nl co!e re use! (or the o#ertion o( the rely+ 0#R't'r (art0 ;a9)t +r't(,ti'n: Normlly sin)le rotor erth (ult is not so !n)erous s the rotor circuit is unerthe! n! current t (ult #oint is ero+ o only lrm is #ro"i!e! on occurrence o( rst rotor erth
(ult+ On occurrence o( the secon! rotor erth (ult ;eteen the #oints o( (ult the el! in!in) )ets short circuite!+ The current in el! circuit increses, resultin) in hetin) o( the el! circuit n! the e9citer+ $ut the more !n)erous is !istur;e! symmetry o( m)netic circuit !ue to #rtil short circuite! coils le!in) to mechnicl un;lnce+ e"ere "i;rtion my seriously !m)e the mchine+ Thus the #rotection circuit shoul! ;e so !esi)ne! s to )i"e n lrm in cse o( st
!e"elo#ment o( 1 rotor erth (ult n! it shoul! tri# the mchine on the occurrence o( &n! erth (ult+ GENERATOR OPERATION:/
The o#ertion o( the )enertor is concerne! ith the ;sic #rocesses o( synchronition, lo!in) , "olt)e mintennce, st;ility n! s(e tri##in)Cshuttin) !on o( the mchine+ In the #oer system the )enertor is reMuire! to o#erte in #rllel ith other runnin) mchines n! to shre ;oth cti"e n! recti"e #oer !emn! o( the system+ !-n,0r'niati'n '; *(n(rat'r: The #rocess o( interconnection o( the )enertor ith the )ri! to hich num;er o( )enertors re lre!y
connecte! is %non s synchronition+ For success(ul synchronition n! #rllel o#ertion o( the )enertor the "olt)e, (reMuency n! #hse seMuence o( the incomin) )enertor must ;e sme s tht o( the )ri!>runnin) system ?+ To !etermine the e9ct instnt o( synchronism synchrosco#e ith three lm#s is #ro"i!e! t the )enertor control !es%+ In some mchine uto synchronition (cility is lso #ro"i!e!+ $e(ore rollin) o( the TG to mtch the s#ee! o( the mchine corres#on!in) to the )ri! (reMuency n! incresin) )enertor terminl "olt)e re!iness o( the mchine itsel( n! it is "rious u9iliries re to ;e ensure+ The synchronition #rocess is to ;e in close coor!intion ith the mechnicl system o( the #oer house+ In )enerl (olloin) o#ertion n! chec%in) re to ;e crrie! out in ste#s ;e(ore synchronition o( the )enertor+ &(;'r( ma,0in( starts r'))in* ,0(,k an (ns9r(/ G(n(rat'r a9i)iar- s-st(m:/
?The lu;e oil Ho to )enertor ;erin)s is !eMute ith correct #ressure n! tem#erture n! there is no oil le%)e+
;?sin)
All the ins#ection in!os re #ro#erly close! n! there is no oil or ter !ro##in) o"er the !uct+ The !ehumi!ier ;loer is o+ N(9tra) *r'9nin* trans;'rm(r"NGT#:
?All the !oors re #ro#erly close! n! loc%e!+ ;?There is no !ro# o( oil or ter on the cu;icle+ G(n(rat'r P.T an s9r*( +r't(,ti'n ,9bi,)(s:
?All /T !rums re com#letely rotte! tor!sCinserte! in ser"ice #osition n! loc%e! in tht #osition n! !oors re #ro#erly close!+ ;?/T (uses re o+%+ n! ti)htly inserte! ithin the )ri#s+ Door (or the ;o9 continin) (uses n! terminl stri# is close!+
ELECTRICAL PROTECTION AND !A6ET% INTERLOC
GENERATOR In )enerl, it is ;se! i( )enertor #rotection relys initite nonseMuentil tri# mo!e>lss A? (or unit isoltion+
seMuentil tri##in) >lss $? #ro"i!es ;etter mens o( tri##in) stem tur;ine )enertor on some ;norml o#ertin) con!ition here !elye! tri##in) o( the )enertor ill not result in increse! !m)e to the tur;ine, )enertor or other electricl eMui#ment+ The reson (or seMuentilly tri##in) stem tur;ine )enertor is to "oi! the o"er s#ee! con!ition tht results hen the )enertor min ;re%er is tri##e! hile stem is su##lie! to the tur;ine+ /ro#er control lo)ic is criticl to the !esi)n o( seMuentil tri##in) scheme sitches, tri# oil system #ressure sitches etc? hich is su#er"ise! ;y n electricl =o Forr! /oer relyC Reser"e /oer rely+ This rely is normlly set to !etect "ery lo #oer le"els n! incor#ortes ;rie( time !ely o( the or!er o( (e secon!s (or !!e! security+ It hs ;een recommen!e! tht )enertor #rotecti"e relys, initites nonseMuentil tri# mo!e (or isoltion o( the unit !ue to electricl (ults+ Only !e"ices #rotectin) unit (rom n ;norml mechnicl o#ertin) con!ition or n ;norml >not (ulte!? electricl con!ition or norml shut !on shoul! initite seMuentil tri#+ Class A =oc%out Rely ill o#erte (or the (olloin) con!itions
in!ictin) mor electricl (ults in the Genertor sttor, Genertor rotor, Genertor Trns(ormer n! 5nit Au9iliry Trns(ormers n! e9cittion trns(ormer n! ssocite! el! $re%er u;icle n! similr other (ults s !etile! ;elo: ? Genertor sttor !ierentil rely o#erte!+ ;? Genertor sttor interturn !ierentil rely o#erte!+ c? Genertor Trns(ormer !ierentil o#erte! !? Genertor Trns(ormer o"erll !ierentil rely o#erte! e? 5nit u9iliry trns(ormer !ierentil rely o#erte! (? Genertor sttor ECF rely>0-7U?o#erte! )? Genertor sttor ECF rely >-7100U? o#erte! h? Genertor rotor erth (ult rely o#erte! i? =oss o( e9cittion rely o#erte! ? Genertor trns(ormer restricte! ECF rely o#erte! %? Genertor o"er "olt)e rely o#erte! l? Genertor re"erse #oer rely o#erte! m? Genertor trns(ormer o"erHu9in) rely o#erte! n? Genertor trns(ormer ;c%u# ECF rely o#erte!
o? 5AT ;c%u# ECF rely o#erte! #? $c%u# !istnce rely o#erte! M? Genertor ne)ti"e seMuence rely o#erte! r? $us !ierentil #rotection rely o#erte! s? GT ;uchhol rely o#erte! t? 5AT ;uchhol rely o#erte! u? Thyristor ;n% (ilure "? Genertor Neutrl isoltor o#en ?E$/ #resse! 9? GT /R>u!!en #ressure rely?
Class-B loc%out rely ill o#erte (or the (olloin) con!itions:
?$oiler tri# ;? Tur;ine tri# c?5AT ;c%u# OC rely o#erte! !?A2R #rotection Class-C loc%out rely ill o#erte (or the (olloin) con!itions:
?$c%u# !istnce rely o#erte! st)e I ;?Genertor ne)ti"e seMuence st)e I c?GT ;re%er #rotection !?GT in!in) tem#ertureC oil tem#erture o#erte! e? 5n!er (reMuency rely o#erte! Unit tri+ s(9(n,(: The !ierence seMuence o( tri##in) shll ;e s mention ;elo: ?$oiler to Tur;ine to Genertor ;?Tur;ine to Genertor c?Genertor to Tur;ine G(n(rat'r () br(ak(r int(r)',ks: Genertor el! ;re%er cn only ;e close! i( the (olloin) #er missi"es re "il;le ?Tur;ine is runnin) t its rte! s#ee!>3000 r#m (or therml mchine ith KC tolernce?+ ;?To ;e !etecte! ;y s#ee! sitch contct t ATR cu;icle c?All )enertor clssA loc%out rely re in reset con!ition
!?Fiel! Hushin) system is helthy G(n(rat'r () br(ak(r tri+ int(r)',ks:
Genertor el! ;re%er cn tri# throu)h the (olloin) inititin) contcts: ?lssA relys o#erte! G(n(rat'r () br(ak(r man9a) tri+ b)',k int(r)',ks: *hen )enertor is in ser"ice mnul tri##in) o( el! ;re%er is not #ermitte! oin) to loss o( e9cittion n! su;seMuent hrm(ul eects on the mchine+ O#ertion o( F rely in!icte tht )enertor is in ser"ice>connecte! in the )ri!? ith its on ;re%er o( ;us cou#ler ;re%er+ One N contct o( F rely is use! in series ith the mnul tri##in) circuit o( the el! ;re%er+ G(n(rat'r () br(ak(r a9t'/tri+ b)',k int(r)',ks:
*hen )enertor is in ser"ice, uto tri##in) >throu)h lssA loc%out contcts? o( el! ;re%er is #ermitte! only (ter o#enin) o( )enertor ;re%er or trns(er $C ;re%er s cse my ;e n! there ;y !ro# out o( F rely to "oi! momentry loss o( e9cittion n! su;seMuent hrm(ul eect on the mchine+
!in*)( Lin( Dia*ram O; G(n(ratin* !tati'n"9nit?@ an 8#
!INGLE LINE DIAGRAM O6 GENERATING !TATION"UNIT/#
GENERATOR TRAN!6ORMER
Trnsmission o( #oer t )enerte! "olt)e is not economicl+ The nee! (or trns(ormers is #rmount (or #oer system consi!erin) the (ct tht trnsmission losses re minimum (or hi)h "olt)es here s !istri;ution hs to ;e !one t the relti"ely s(e "olt)e+ In essence the trns(ormer Ztrns(orms "olt)e n! current one le"el to "olt)e n! current t nother le"el hile %ee#in) the (reMuency n! #oer le"el unltere!+ o )enertor out#ut "olt)e is ste# u# to the trnsmission "olt)e system "olt)e ;y trns(ormer %non s Genertor trns(ormer>GT?+ #city o( )enertor trns(ormer is !etermine! ;se! on the .2A c#city o( )enertor+ The o#en ty#e terminls o( the <2 ;ushin) o( the )enertor trns(ormer re connecte! to sitchyr! con!uctor throu)h G$+ The =2 terminls re %e#t suit;ly enclose! to (cilitte! connection to )enertor ;us !uct+ oolin) metho! !o#te! is OFAF+ In .T/ 5nit61 to ', GTs re sin)le 3 #hse trns(ormer n! in #hse II, GTs re ;n% o( three sin)le #hse trns(ormers + The only ste# u# trns(ormer is GT in this sttion+
GENERATOR TRAN!6ORMER !+(,i,ati'n '; GT:/ Unit+ , to 2 .%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( =2>B2?: =ine urrent o( <2>Am#?: =ine urrent o( =2>Am#?: Tem#erture rise o( oil>Q?:
$
Tem#erture rise o( in!in)>Q?: 47 o"er m;ient o( 70Q *ei)ht: ore n! in!in)s>%)?: 13-000 om#lete Trns(ormer inclu!in) oil>%)?: 3080 Trns#ort>%)?: &38100 Insultion le"el: <2 I 870 =I 1070 =2 =I -7 A 70 <+2+N =I 180 A 80 Unit+ 3 an) -
.%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?:
$
No =o! 2olt)e o( =2>B2?: 1'+7 =ine urrent o( <2>Am#?: 878+88 =ine urrent o( =2>Am#?: 110&&+14 Tem#erture rise o( oil>Q?: 40 o"er m;ient o( 70Q Tem#erture rise o( in!in)>Q?: 47 o"er m;ient o( 70Q *ei)ht: ore n! in!in)s>%)?: 1'7000 om#lete Trns(ormer inclu!in) oil>%)?: &73&70 Trns#ort>%)?: 10000 Oil Muntity>lit?: 78000 Insultion le"el: <2 I 870 =I 1070 =2 =I -7 A 70 <+2+N =I 180 A 80 Unit+/ an) 0 .%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?:
$
/hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( =2>B2?: =ine urrent o( <2>Am#?: =ine urrent o( =2>Am#?: Tem#erture rise o( oil>Q?:
1 @N!11 4&0C[3 &1 &4+8-7&3+ 40 o"er m;ient o( 70Q
Tem#erture rise o( in!in)>Q?: 47 o"er m;ient o( 70Q *ei)ht: ore n! in!in)s>%)?: 1737&0 om#lete Trns(ormer inclu!in) oil>%)?: &78700 Trns#ort>%)?: 184-00 Oil Muntity>lit?: 7'&&0 Insultion le"el: <2 I 110 =I 14&7A 3
UNIT TRAN!6ORMER:
There is one unit trns(ormer (or ech unit in #hse ii+ There re some mchines hose o#ertin) "olt)e is 11%"+To su##ly these mchines e h"e to ste# !on the )enertin) "olt)e+ These cn ;e !one ;y unit trns(ormer ;y t##in) (rom )enertin) terminl+ 5nit trns(ormer ste# !on the "olt)e &1%" to 11 %"+ This is three #hse trns(ormer+ $ut, in cse o( unit61to ' there is no nee! o( 5T, ;ecuse there is only to "olt)e le"el'+'%" n! 417"+
.%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse:
!+(,i,ati'n '; UT:/
$
onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( =2>B2?: =ine urrent o( <2>Am#?: =ine urrent o( =2>Am#?: Tem#erture rise o( oil>Q?: Tem#erture rise o( in!in)>Q?:
Dyn1 &1 11+7 1&3+'4 &&'1+8 40 o"er m;ient o( 70Q 47 o"er m;ient o( 70Q
*ei)ht: ore n! in!in)s>%)?: 400'7 om#lete Trns(ormer inclu!in) oil>%)?: '&07 Trns#ort>%)?: 70000 Oil Muntity>lit?: &770 Insultion le"el: <2 =I 1&7A 70 =2 =I 87A & Unit A9i)iar- Trans;'rm(r:
The norml source o( <2 #oer to unit u9iliries is unit u9iliry trns(ormer+ The siin) o( the 5AT is usully ;se! on the totl connecte! c#city o( runnin) unit u9iliries i+e e9clu!in) the stn! ;y !ri"es+ It is s(e n! !esir;le to #ro"i!e ;out &0U e9cess c#city thn clculte!+ *ith the hel# o( 5AT e ste##e! !on the )enerte! 17+87%" >in cse o( unit61to4? n! 1'+' %">in cse o( unit67,'? into '+'%" to su##ly the '+'%" u9iliry !ri"es+ $ut, in cse o( #hse II 5AT is use! to ste##e! !on the 11%" "olt)e into 3+3%" to su##ly the 3+3 %" mchines n! its hi)h "olt)e terminl is connecte! to 5T n! there is to 5AT (or ech 5T+
!+(,i,ati'n '; UAT:/ 6'r Unit? 1t' 5 .%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?:
Atlnt Electricl /"t+=t!+ ONAFCONAN 1'C1&+70 1'C1&+70 70 3 Dyn11 17+8
No =o! 2olt)e o( =2>B2?: =ine urrent o( <2>Am#?: =ine urrent o( =2>Am#?: Tem#erture rise o( oil>Q?: Tem#erture rise o( in!in)>Q?: *ei)ht: ore n! in!in)s>%)?: *ei)ht o( oil>%)?: Totl ei)ht>%)?: Oil Muntity>litre?: Insultion =e"el: <2 : =2 :
'+7'+7 C47+& 133+C1047+40Q 47Q 14300 '00 30700 8'70 -7 B2/ 3 B2 rms 30 B2/ &0 B2 rms
For Unit+3 an) -
.%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( =2>B2?: =ine urrent o( <2>Am#?: =ine urrent o( =2>Am#?: Tem#erture rise o( oil>Q?: Tem#erture rise o( in!in)>Q?: *ei)ht: ore n! in!in)s>%)?: *ei)ht o( oil>%)?: Totl ei)ht>%)?: Oil Muntity>litre?: Insultion =e"el: <2 : =2 :
$
For Unit+/ an) 0
.%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( =2>B2?: =ine urrent o( <2>Am#?: =ine urrent o( =2>Am#?: Tem#erture rise o( oil>Q?: Tem#erture rise o( in!in)>Q?: *ei)ht: ore n! in!in)s>%)?: *ei)ht o( oil>%)?: Totl ei)ht>%)?: Oil Muntity>litre?: Insultion =e"el: <2 : =2 :
$
DISTRI4UTION TRANSFORMER
To su##ly the 417" rte! motors e use this !istri;ution trns(ormer hich ctully ste#s !on the '+'%" su##ly into 417"+ome o( the !istri;ution trns(ormer re !ry ty#e i+e nturl coolin) system is use! here+For ech unit>1 to '? there re !istri;ution trns(ormer insi!e #lnt+
.RATING. .%e: Ty#e o( oolin): Rtin)>B2A?: Rte! urrent <+2>Am#s?: Rte! urrent =+2>Am#s?: 2ector Grou#:
$
.o!el: AT REIN DR@ T@/E FreeMuency: 70< Tem#erture Rise O"er 700c Am;ient t 7+7U rte! "olt)e: 0 0c Insultion le"el <+2: 87B2#C&B2 rms Insultion lss: F *ei)ht>B)?: 7700
!TATON !ERVICE TRAN!6ORMER"!!T#:
Norml source to the sttion u9iliries n! stn! ;y source to the unit u9iliries !urin) strt u# n! (ter tri##in) o( the unit is ttion er"ice trns(ormer+ \untity o( sttion er"ice trns(ormers n!there c#city !e#en!s u#on the unit sies n! num;ers+ Ech sttion ser"ice trns(ormer shll ;e one hun!re! #ercent stn! ;y o( the other+ ttion ser"ice trns(ormers shll cter to the simultneous lo! !emn! !ue to strt u# #oer reMuirements (or the lr)est unit, #oer reMuirement (or the sttion u9iliries reMuire! (or runnin) the sttion n! #oer reMuirement (or the unit u9iliries o( runnin) unit in the e"ent o( out)e o( the unit source o( su##ly+ There is three T (or unit61 to 4 n! to T (or unit67 n! '+Its ste#s !on &&0 %" )ri! "olt)e to '+' %" "olt)e n! su##ly to ;or!A$>ommon Au9iliry $or!? n! E$>trtu# Emer)ency $or!?+ For 1nit+, to 2
.%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( T2>B2?: No =o! 2olt)e o( =2>B2?: =ine urrent o( <2>Am#?: =ine urrent o( T2>Am#?:
$
Tem#erture rise o( oil>Q?: Tem#erture rise o( in!in)>Q?: *ei)ht: ore n! in!in)s>%)?: *ei)ht o( oil>%)?: Totl ei)ht>%)?: For 1nit+3 an) .%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( =21>B2?: =2&>B2?: '+=ine urrent o( <2>Am#?: =ine urrent o( =21>Am#? n! =2&: Tem#erture rise o( oil>Q?: Tem#erture rise o( in!in)>Q?: *ei)ht: ore n! in!in)s>%)?: *ei)ht o( oil>%)?: Totl ei)ht>%)?:
40 47 34400 &-770 &14000 $
But in case of phase II this scheme is dierent and this is elaborated below!TATION TRAN!6ORMER "!T#:
Norml source to the sttion u9iliries n! stn! ;y source to the unit u9iliries !urin) strt u# n! (ter tri##in) o( the unit is ttion trns(ormer+ \untity o( sttion trns(ormers n! there c#city !e#en!s u#on the unit sies n! num;ers+ Ech sttion trns(ormer shll ;e one hun!re! #ercent stn! ;y o( the other+ ttion trns(ormers shll cter to the simultneous lo! !emn! !ue to strt u# #oer reMuirements (or the lr)est unit, #oer reMuirement (or the sttion u9iliries reMuire! (or runnin) the sttion n! #oer
reMuirement (or the unit u9iliries o( runnin) unit in the e"ent o( out)e o( the unit source o( su##ly+ *e h"e to sttion trns(ormer in 400%" sitchyr!+ It ste#s !on the 400%" )ri! "olt)e to 11%" "olt)e+ !TATION AU7ILIAR% TRAN!6ORMER"!AT#:
ttion u9iliry trns(ormer is lso ste# !on trns(ormer+ It ste#s !on 11%" "olt)e to 3+3%" "olt)e+ It is minly use! to su##ly the 3+3 %" mchines+ Its hi)h "olt)e is connecte! to the secon!ry o( the T+ Its use is similr to the 5AT t strtin) con!ition n! tri##in) con!ition+ There is to AT (or ech T+
!+(,i,ati'n '; !T:/ .%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse:
$
onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( =21>B2?: =2&>B2?: 11+7 =ine urrent o( <2>Am#?: =ine urrent o( =21>Am#?: =2&>Am#?: &&'1+Tem#erture rise o( oil>Q?: Tem#erture rise o( in!in)>Q?: *ei)ht: ore n! in!in)s>%)?: *ei)ht o( oil>%)?: Totl ei)ht>%)?: Oil Muntity>litre?: Insultion le"el: <2 : =2 1: =2&:
@n0 @n0 @n0 400 11+7 130 &&'1+40 47 -8'7470 &14000 '810
=I 1300A3 =I 87 A& =I 87A&
!+(,i,ati'n '; !AT:/ .%e: Ty#e o( coolin): Rtin) o( <2>.2A?: Rtin) o( =2>.2A?: FreMuency><?: /hse: onnection sym;ol: No =o! 2olt)e o( <2>B2?: No =o! 2olt)e o( =2>B2?: =ine urrent o( <2>Am#?: =ine urrent o( =2>Am#?: Tem#erture rise o( oil>Q?: Tem#erture rise o( in!in)>Q?:
$
U!T > !!T:/ There re other to ty#es o( ste#!on 3 #hse trns(ormer (or internl o#ertion, %non s 5T n! T+ 5T is (e! (rom 5T sitch ;or! n! T is (e! (rom T sitch ;or!+ These re !ry cst resin Then! "olt)e is 11B2C4332 (or ;oth the ty#e trns(ormer+ Airtrns(ormer+ nturl coolin) Dyn1rtio connection is use!+
NGT "NEUTRAL GROUNDING TRAN!6ORMER#: The NGT is use! to #re"ent the )enertor (rom erth (ults+ It com#rises o( #rimry in!in) n! secon!ry in!in), the secon!ry in!in) is connecte! ith lo "lue resistnce+ *hen e"er erth (ult rises he"y current Hos to the #rimry in!in) n! s result n em( is in!uce! in the secon!ry+ The "olt)e !ro# cross the resistnce is sense! ;y the NGT rely n! it ctutes to ctute the G$>)enertor circuit ;re%er? n! thus the )enertor is tri##e!+ $siclly NGT is ste#!on>&1B2C&&02? trns(ormer+
TRAN!6ORMER AU7ILARIE!: For #ro#er (unctionin) o( the trns(ormer it is #ro"i!e! ith se"erl u9iliries su; systems+ $siclly they re:
COOLING !U& !%!TEM:
•
•
•
•
onsi!erin) the su;stntil mount o( lo! !eli"ere! ;y #oer trns(ormer #ro#er coolin) system hs to ;e in #lce in or!er to #re"ent ny hr!s+ .ostly, OFAF>Oil Force! Air Force!? or ONAF>Oil Nturl Air Force!? schemes re use!+ There re r!itors n! (ns s ell+ For OF ty#e coolin) ;utterHy "l"e is %e#t to #um# oil+ CON!ERVETOR: ince oil to #lys mor role The in the coolin) o( #reser"es trns(ormer hencethe it hs ;e mintine!+ conser"tor the oil o( the trns(ormer hile e9#nsion o( oil+ &UCHHOL RELA%: It is #rotecti"e !e"ice use! only in oil immerse! trns(ormer+ It #ro"i!es #rotection )inst to ty#es o( (ult,incipient fault n! severe fault+ 5n!er inci#ient (ult it )i"es n lrm n! un!er se"ere (ult it tri#s the trns(ormer (rom the line ;y usin) to Hots hich cts s sitch+ It is uni"erslly use (or trns(ormer h"in) rtin) more thn 870 B2A+ &REATHER: The ;rether ;siclly ;sor;e! ny moisture tht my ;e cuse! !ue to "#orition o( the oil in trns(ormer+ It contins silic )el, hich chn)es colour (rom ;lue to ohite s it ;sor;s moisture+ Thus it #ro"i!es n in!ictor mechnism (or the Mulity o( the oil+ PROTECTION MECHANI!M!: There re tem#erture sensors, hich cn lrm i( the tem#erture rises ;eyon! certin limit+ Also the ter su##ly )ets cti"te! in cse o( hr!s li%e re+
There re lso %e#t RTD>resistnce tem#erture !etector? n! /R2>#ressure relie( "l"e? (or s(ety+
SWITCHYARD It is sitchin) sttion ,hich hs the (olloin) cre!its: V .in lin% ;eteen )enertin) #lnt n! trnsmission system, hich hs lr)e inHuence on the security o( the su##ly+
V te#u# n!Cor ste#!on the "olt)e le"els !e#en!in) u#on the Netor% no!e+ V itchin) ONCOFF recti"e #oer control !e"ices, hich h"e eect on Mulity o( #oer+ In .T/ hs minly to sitchyr!s+ one is &&0B2 n! nother one is 400B2+ These to sitchyr!s re o( three ;us system>lso clle!, one n! hl( ;us system?+ 1+ .in ;us I &+ .in ;us II 3+ Trns(er ;us
!in*)( Lin( Dia*ram '; 223kv swit,0-ar
in)le =ine Di)rm O( 400%" itchyr! E\5I/.ENT O..ON=@ FO5ND IN *IT<@ARD: 1+ &+ 3+ 4+ 7+ '+ 8+ + -+
ircuit $re%ers urrent Trns(ormer /otentil Trns(ormer #citor 2olt)e Trns(ormer Isoltor Erth itch =i)htnin) Arrester *"e tr#s $us ;r lm# ttin)s
1. CIRCUIT &REAsin)le ;re%? n! in the 33%"
sitchyr! e h"e 2$+ In the 400%" sitchyr! e h"e !ou;le ;re% F] $+ This ty#e o( $ rrn)ement consist o( i? )r!ient c#citor, ii? ;re%, iii? #reinsert resistor+ The )s is #ut insi!e the circuit ;re%er ;y (orce un!er hi)h #ressure+ *hen i( the )s )ets !ecreses there is motor connecte! to the circuit ;re%er+ The motor strts o#ertin) i( the )s ent loer thn &0+ ;r+ There is meter connecte! to the ;re%er so tht it cn ;e mnully seen i( the )s )oes lo+ The circuit ;re%ers use the F] )s to re!uce the torMue #ro!uce in it !ue to ny (ult in the line+ The circuit ;re%er hs !irect lin% ith the instruments in the sttion, hen ny (ult occur lrm ;ell rin)s+ In sin)le ;re% ty#e only the ;us ;r en! is isolte! ;ut in !ou;le ;re% ty#e, ;oth ;us ;r>source? n! c;le >lo!? en!s re ;ro%en+ CIRCUIT 4REAER
"D'9b)( &r(ak#
"!in*)( &r(ak#
2. CURRENT TRAN!6ORMER:/
urrent trns(ormers re ;siclly use! to t%e the re!in) o( the currents enterin) the sttion+ This trns(ormer ste#s !on the current (rom 1'00m#s to 1 m#+ This is !one ;ecuse e h"e no instruments to mesure such ty#e o( hu)e mount current+ This ty#e o( trns(ormer re use! to i? #rotection ii? mesurement #ur#ose+ There re 7 cores use! in this ty#e o( T+
CURRENT TRAN!6ORMER 4.POTENTIAL TRAN!6ORMER:/ /otentil trns(ormers ser"e num;er o( (unctions in #oer system+ They re reMuire! (or the o#ertion o( mny ty#es o( instrumenttions n! rely #rotecti"e systems+ They re minly use! to
ste# !on the m)nitu!e o( "olt)e to s"e"olt)e "lue to incor#orte mesurin) n!hi)h #rotection lo)ics+ They mesures n! in conunction ith T, they mesure #oer+ They (ee! synchroniin) eMui#ments+ They cn ;e use! s cou#lin) c#citor in #oer line
crrier netor%+This is use! in &&0B2 itchyr!+
"POTENTIAL TRAN!6ORMER# 5. CAPACITOR VOLTAGE TRAN!6ORMER"CVT#:/
A c#citor "olt)e trns(ormer >2T? is trns(ormer use! in #oer system to ste# !on e9tr hi)h "olt)e si)nls n! #ro"i!e lo "olt)e si)nl either (or mesurement or to o#erte #rotecti"e rely+ In
its most ;sic (orm it consist o( three #rts: to c#citor cross hich the "olt)e si)nl is s#lit, n in!ucti"e element use! to tune !e"ice to the su##ly (reMuency n! trns(ormer to isolte n! (urther ste# !on "olt)e (or instrumenttion n! #rotecti"e rely+ The !e"ice hs t lest (our terminls, hi)h "olt)e terminl (or connection o( hi)h "olt)e si)nl, )roun! terminl n! t lest one set o( secon!ry terminls (or connectin) to the instrumenttion n! #rotecti"e rely+ 2Ts re ty#iclly sin)le #hse !e"ice use! (or mesurin) "olt)e in e9cess o( one hun!re! %ilo"olts here the use o( "olt)e trns(ormer oul! ;e uneconomicl+ In #rctice the rst c#citor, 1 is o(ten re#lce! ;y stc% c#citor connecte! in series+ This result in lr)e "olt)e !ro# cross the stc% o( c#citor tht re#lce! the rst c#citor n! com#rti"ely smll "olt)e !ro# cross the secon! c#citor, & n! here the secon!ry terminls+ @.I!OLATOR:/ $siclly n isoltor is olo! sitch+ The use o( this isoltor is to #rotect the trns(ormer (rom the other instrument in the line+ The isoltor isoltes the e9tr "olt)e to the )roun! n! thus ny e9tr "olt)e cnnot enter the line+ Thus n isoltor is use! (ter the ;us (or #rotection lso+ To isoltor must ;e %e#t in ;oth si!e o( ;re%er+ Ty#e o( isoltor use! in &&0B2: i?entrl Rotte Dou;le $re%
"CRD&#
Ty#es o( isoltor use! (or 400B2: i? <$>horiontl centrl ;re%? ii? #nto)r#h
HC&
Pant'*ra+0 is')at'r
8. EARTH !ITCH:/
Erth sitch !ischr)es the c#citi"e "olt)e store! in line on )enertor si!e in isolte! system ust (ter o#enin) o( $ n! isoltor+ *hen erth sitch is connecte! to the isolte! ;ut un !ischr)e! system it !ischr)es the store! ener)y to the erth, so tht mintennce or% cn ;e crrie! out either in line or in )enertor si!e+ Erth sitch shoul! ;e o#erte! only hen the isoltors re o#en+ In .T/ ll erth sitches cn ;e o#erte! mnully+
EARTH !ITCH
. LIGHTENING ARRE!TOR:/ =i)htenin) rrestors re the instruments tht re use! in the incomin) (ee!ers so tht to #re"ent the hi)h "olt)e enterin) the min sttion+ This hi)h "olt)e is "ery !n)erous to the instruments use! in the su;sttion+ E"en the instruments re "ery costly, so to #re"ent ny !m)e li)htenin) rrestors re use!+ The li)htenin) rrestors !o not let the li)htin) to (ll on the sttion+ I( some li)htenin) occurs the rrestors #ull the li)htenin) n! )roun! it to the erth+ In ny su;sttion the min im#ortnt is o( #rotection hich is rstly !one ;y these li)htenin) rrestors+ The li)htenin) rrestors re )roun!e! to the erth so tht it cn #ull the li)htenin) to the )roun!+ The li)htenin) rrestors or% ith n n)le o( 30Q to 47Q m%in) cone+ In 400%" sitchyr! )#less rrestor re use! )# less mteril is ^nOX+
LIGHTENING ARRE!TOR
AVE TRAP
B. av( Tra+s:/ *"e tr# is nothin) ;ut =R circuit hich cn tr# the hi)h (reMuency communiction si)nls sent on the line (rom the remote su;sttion n! !i"ertin) them to the telecomCtele #rotection #nel in the su;sttion control room >throu)h cou#lin) c#citor n!
=.5?+This is rele"nt in /oer =ine crrier ommuniction>/=? systems (or communiction mon) "rious su;sttion ithout !e#en!ence on the telecom com#ny netor%+ The si)nls re #rimrily tele #rotection si)nls n! in !!ition , "oice n! !t communiction si)nls throu)h sme #oer line+ The "e tr# oers hi)h im#e!nce to the hi)h (reMuency communiction si)nls thus o;structs the Ho o( these si)nls in to the su;sttion ;us;rs+ I( there ere not to ;e there, then si)nl loss is more n! communiction ill ;e ineecti"eC#ro;;ly im#ossi;le+ The totl systems occurs ;y usin) mo!ultionC!emo!ultion (ctors throu)h trnsmitter n! recei"er+ .&9s bar > C)am+ ttin*s:/
The ;us is line in hich the incomin) (ee!ers come into n! )et into the instruments (or (urther ste# u# or ste# !on+ There my ;e !ou;le line in the ;us so tht i( ny (ult occurs, other cn or%s+ Thus the su##ly ill not sto#+ In .T/ there h"e to sitchyr!s ith three ;us+ i?.in ;us1 ii?.in ;us Y& Y$uses re min source o( #oer in #oer system )ri! the )enertors or the lterntor re connecte! in #rllel to the min ;us 1 or & to su##ly the #oer in the )ri!+ iii?Trns(er ;us_5sully there is no #oer t the time o( norml o#ertion so trns(er o( ;e )enertin) sttion+ *hen;us+ there in certin in line #oer;us cnnot trns(erre! to min ois (ult trns(er ;us is use! to trns(er the #oer (rom one min ;us to other min ;us+ In .T/ &&0B2 sitchyr! hs 31no+o( $y+Amon) them si9 (or GT,tel"e (or =ine,"e (or T,to (or 0.2A Trns(ormer,(our (or $us cou#ler,to (or $us tie n! 400B2 sitchyr! hs 10 no+ o( ;y+ Amon) them (our line ;y, to (or GT, to (or T, one (or ;ustie n! nother
one is ;us cou#ler+ .inly ;us cou#ler is use! to mintin the su##ly un!er (ult con!itions o( ;re%er+ 13.IN!ULATOR!:/ The o"erhe! line con!uctors re ;re n! not co"ere! ith ny insultin) mterils+ The line con!uctors re there(ore, secure! to the su##ortin) structures ;y mens o( insultin)
9tures, clle! insultors, in or!er tht there is no current le%)e to the erth throu)h the su##orts+ Insultors re mounte! on the cross rms n! the line con!uctors re ttche! to the insultor so s to #ro"i!e the con!uctors #ro#er insultion n! lso #ro"i!e necessry clernce ;eteen con!uctors n! metl or%s+ The insultors must #ro"i!e #ro#er insultion n! necessry clernce )inst the hi)hest "olt)e in orst tmos#heric con!itions to hich the line is li%ely to ;e su;ecte!+ The insultor lso #re"ent short circuitin) ;eteen the !ierent #hse con!uctors n! #ro"i!e necessry mechnicl su##ort (or the line con!uctors+ Thus the insultors un!ou;tly one o( the most im#ortnt n! "ulner;le lin%s in trnsmission n! !istri;ution o( o"erhe! trnsmission n! !istri;ution+ In .T/ sitchyr!s minly !isc ty#e, strin) ty#e, #in ty#e insultors re use!+
RATINGS !68 CIRCUIT &REA
Rte! "olt)e &47B2 Rte! Im#ulse ithstn! "olt)e B2 Rte! #oer (reMuency "olt)e B2# Rte! (reMuency < Rte! norml current A Rte! short time current Rte! shortcircuit !urtion First #ole to cler (ctor ymmetricl :40 BA $re%in) c#city Y eMui"lent .2A Asymmetricl : 4'+4BA Rte! m%in) current BA# Rte! #ressure o( hy!rulic o#erte! mechnism )u)e ;r Rte! #ressure o( F] t &0Q>)u)e? *ei)ht o( com#lete ;re%er *ei)ht o( F] )s Rte! tri# coil "olt)e &&02>D? Rte! closin) coil "olt)e &&02>D?
: :1070 :4'0 :70 :&000 :40 BA :1 s :1+3
:1-000
:100 :&70370 :'+7 ;r :4071%) :&7 %) : :
!6K CIRCUIT &REA
Rte! "olt)e B2 Rte! Im#ulse ithstn! "olt)e 1070C14&7 B2# Rte! #oer (reMuency "olt)e 7&0C'10 B2 Rte! (reMuency < Rte! norml current A Rte! short time current Rte! shortcircuit !urtion First #ole to cler (ctor ymmetricl BA $re%in) c#city Y eMui"lent
:4&0 : : :70 :3170 :40 BA :1 s :1+3 :40
.2A Asymmetricl :7&+7 BA Rte! m%in) current BA# Rte! #ressure o( hy!rulic o#erte! mechnism )u)e ;r Rte! #ressure o( F] t &0Q>)u)e? *ei)ht o( com#lete ;re%er *ei)ht o( F] )s %) Rte! tri# coil "olt)e &0 10 2olt D Rte! closin) coil "olt)e &0 10 2olt D
:&-000
:100 :313 ` 3 :8+7 ;r :-11 %) :78+7 :&&0K
: &&0K
CENTRAL ROTATE DOU&LE &REA< I!OLATOR .%e Ty#e 2olt>%"? $I=>%"?
:<+=+.+In!ustries :RD$ :&47 :1&70
>%ACsec?
:40 urent>Am#? Ty#e o( Dri"e .otor 2olt)e>A?>2? ontrol %t+ 2olt)e>D+?>2?
:1&70 :.otor :417 :&30 HORIONTAL CENTRAL &REA<
I!OLATOR Ty#e 2olt> B2? $I= >B2? itchin) Im#ulse>B2? /a >B2? T>BACsec? *ei)ht o( isoltor>%)? FreMuency><? urrent>A? Ty#e o( !ri"e .otor "olt)e>A?>2? ontrol "olt)e>D?>2? *ei)ht o( !ri"e>%)?
:<$ :4&0 :14&7 :1070C1&47 :'10 :40 :1-70 ##ro9 :70 :&000 :.otor :417 :&&0 :100
PANTOGRAPH T%PE I!OLATOR Ty#e 2olt> B2? $I= >B2? itchin) Im#ulse>B2? /a >B2? T>BACsec? *ei)ht o( isoltor>%)? FreMuency><? urrent>A? Ty#e o( !ri"e .otor "olt)e>A?>2? ontrol "olt)e>D?>2? *ei)ht o( !ri"e>%)?
:/nto)r#h :4&0 :14&7 :1070C1&47 :'10 :40 :1-70 ##ro9 :70 :&000 :.otor :417 :&&0 :100
EARTHING !ITCH Ty#e 2olt> B2? $I= >B2? T>BACsec? *ei)ht o( isoltor>%)? FreMuency><? urrent>A?
:Telesco#ic :4&0 :14&7 :40 :8C#ole :70 :&000
Ty#e o( !ri"e .otor "olt)e>A?>2? ontrol "olt)e>D?>2? *ei)ht o( !ri"e>%)?
:.otor :417 :&&0 :100
PROTECTION O6 !ITH%ARD: The min #rotections re )i"en to line ;us;rs un!er !ierent (ults re 1+Distan,( +r't(,ti'n: In this ty#e, the rely o#ertes hen the rtio o( the "olt)e current chn)es ;eyon! s#ecie! limit+
&+Ov(r ,9rr(nt +r't(,ti'n: All ;uses h"e s#ecic limit to Ho the current, i( current is more ;eyon! this limit, then the oCc rely ill o#erte+ 3+Ov(r v')ta*( +r't(,ti'n: me s oCc #rotection ,ll ;uses h"e s#ecic limit to ithstn! m9imum "olt)e, i( this "olt)e is o"er, then the o"er "olt)e rely ill o#erte+ 4+Eart0;a9)t +r't(,ti'n: Erth (ult #rotection is one o( the min #rotection o( the lines+ I( there occur ny erth (ult, the erth (ult rely ill o#erte+ 7+Dir(,ti'na) +r't(,ti'n : ometimes (ter occurrin) the erth (ult in line in r!il system, then the !irection o( the current my chn)e+ Then the !irectionl rely ill o#erte+ !TATION GROUNDING !%!TEM: /oer sttion )roun!in) system shll ;e !esi)ne! ? to o;tin eecti"ely lo neutrl to )roun!
resistnce (or limitin) the system o"er "olt)e n! i! the o#ertion o( the #rotecti"e relys in the e"ent o( )roun! (ults n! ;? to limit !n)erous #otentil )r!ients lon) the sur(ce !urin) short circuit currents (or ensurin) s(ety o( o#ertin) #ersonnel+ Normlly se#rte )roun! )ri!s ;urie! ;elo the erth t !e#th o( 0+7 mts re constructe! (or the #oer house n! the sitchyr!+ These to )ri!s re interconnecte! t se"erl #oints, The )ri! consists o( &0 mm !i+ . ro! rrn)e! in mesh (orm n! el!e! t the inter section #oints+ To im#ro"e the con!ucti"ity ;eteen the erth n! the )ri! "erticl s#i%es re inserte! !ee# into the erth n! el!e! to these horiontl ro!s+ Erth #its re lso constructe! hen reMuire!+ 2erticl risers re t%en (rom the )roun! )ri! (or connection to the )roun! ;us ;o"e the sur(ce+ In )roun!e! system the neutrl #oint o( trns(ormer or tht o( )enertor is connecte! to this ;us throu)h resistnce or )roun!in) trns(ormer or !irectly s the cse my ;e+ All, the non current crryin) metllic #ortions o( electricl eMui#ments >such s the enclosure, c;le ;o9 etc? , steel structures , toers, #ole etc re to ;e connecte! to this )roun! ;us+
MOTOR!: D(niti'n: Electric motors re electrom)netic ener)y con"erters hose (unction is ;se! on the (orce e9erte! ;eteen electricl currents n! m)netic el!s_hich re usully electriclly e9cite! s ell+ It ;siclly con"erts electricl ener)y into mechnicl ener)y+
Vari'9s t-+(s '; m't'rs: • •
•
D motors: shunt series n! com#oun! A motors: sin)le #hse, three #hse synchronous motors, in!uction motors+ 2olt)e: ser"o? motor+
A,,'rin* t' t0( t-+(s '; (,itati'n m't'rs ar( ivi( int' tw' t-+(s: !in*)- (,it(:
AC in9,ti'n m't'r: An in!uction motor is n lterntin) current motor in hich the #rimry in!in) o( the sttor is connecte! to the #oer source n! secon!ry in!in) or sMuirrel c)e secon!ry in!in) o( the rotor crries the in!uce! current+ There is no #hysicl electricl connection to the secon!ry in!in), in its current is in!uce!+ D'9b)- (,it(: !-n,0r'n'9s m't'r: It hs con"entionl three #hse sttor+ Its rotor in!in) is D e9cite! n! its s#ee! is !e#en!ent on the num;er o( #irs o( sttor #oles+ True synchronous motor is not sel( strtin), sMuirrel c)e motor or oun! rotor motor re reMuire! to ccelerte to ner synchronous s#ee!+ *hen o#ertin) t synchronous s#ee! the #oer (ctor o( the motor cn ;e chn)e! ;y "ryin) the !e)ree o( e9cittion+
T-+(s '; AC m't'rs: •
•
•
•
Muirrel c)e in!uction motor: 3 #h+ *in!in) in sttor, co##er ;rs in rotor+ *oun! rotor:3 #h+ *in!in) in sttor, 3 #h+ *in!in) in rotor>shorte! internlly?+ *oun! rotor ith sli# rin): 3 #h+ *in!in) in sttor, 3 #h+ *in!in) in rotor>terminte! to sli# rin)s?+ ynchronous motor: 3 #h+ *in!in) in sttor, D in!in) in rotor>terminte! to sli# rin)s?
A,,'rin* t' v')ta*( )(v():There re lso to ty#es o( A motors, clle! *C2CAm#s?
$F/: ID Fn: FD Fn: /A Fn: ol .ill: $*>$oiler circultin) /um#?: E/>on!ense E9trction /um#?: om#ressor .otor:
4+'.*C'+'B2C4'-A 1&7B*C'+'B2C&0&A &7B*C'+'B2C-1A 1&87B*C'+'B2C133+7A &400B*C'+'B2C&'4A 77B*C'+'B2C-+7A 3&7B*C'+'B2C3'A &70B*C'+'B2C&A
ircultion *ter /um#:
1-&0B*C'+'B2C&17A
In this #oer #lnt ,the motor hose o#ertin) "olt)e is 11%" n! 3+3%" , %non s *CB2CAm#s?: .D $F/ :10 .*C11B2C'07A ID Fn :3400B*C11 B2C&7&&A >ynchronous .otor? FD Fn :1038B*C11 B2C80+4A /A Fn :&-&7B*C11B2C18'A ol .ill :7&7B*C3+3B2C1&'+7A $*>$oiler circultin) ter #um#? :370B*C3+3 B2C-+1A E/>on!enste e9trction #C#? :-00 B*C3+3 B2C1-1A om#ressor .otor :317 B*C3+3 B2 LT MOTOR!: In this #oer #lnt there re so mny motors hich o#ertes t 417 2 (or !ierent #ur#ose, these motors re clle! =T motors+
C)assi,ati'n '; in9,ti'n m't'rs: •
•
Muirrel c)e in!uction motors: This entire in!in) is m!e u# o( he"y co##er ;rs connecte! to)ether t ech en! ;y metl rin) m!e o( co##er n! ;rss+ No insultion is reMuire! ;eteen the core n! the ;rs+ This is ;ecuse o( "ery lo "olt)e )enerte! in the rotor ;rs+ li# rin) or oun! motors: There rotor resistnce cn ;e increse! ;y insertin) n e9ternl resistnce throu)h the sli# rin)s+
P(r;'rman,( t(rms: E((iciency: b LP dt C / in+L 1 Y >/ lossCP in? .otor lo!in): Actul o#ertin) lo! to the motorC Rte! c#city o( the motor /oer (ctor: os W L >B*CB2A? M't'r )'ss(s: ore loss ttor n! rotor resistnce losses Friction n! in!)e losses
try lo! losses
2rious insultion: lss o( insultion: .9 llo;le tem#>Q?:
@ -0
A 107
E 1&0
$ 130
F < 177 10
R(as'ns ;'r t0( ;ai)9r( '; m't'rs:
$! mnu(cturin) Mulity ontinuous o"er lo!in) FreMuent strts in short !urtion Incorrect settin) C cli;rtion o( #rotection Im#ro#er mintennce Filure o( interloc%s
DC !%!TEM:
There re lys %e#t D system to o#erte the u9iliry system un!er emer)ency con!ition such s strt u# , tri##in) o( the TG , (ilure o( A+ In .T/ #hseII to ;ttery ;n%s re #resent, one (or Internl #oer house, nother (or sitchyr! control+ In sitchyr! control room there is ;ttery room n! n A D$ room+ &&0 "olt D (or controllin) the #rotection system n! 4 "olt D (or /= system+ There lso ;c% u# ;ttery ;n% is %e#t+ $tteries re connecte! in series+ For chec%in) the helthiness o( the ;ttery s#ecic )r"ity mesurement is !one #erio!iclly ;y hy!rometer+ In A D$ room Flot n! Flot cum $oost chr)er re %e#t+ #city o( ;ttery : '47 Ah>&&02 D? &70Ah>42 D? Totl ;ttery : 110>&&02 D? &4>42 D? @8?L No+ o( #ositi"e #lte>'?K1+ @B/&1 (or 4" D+
DIE!EL GENERATOR:
In the $lc% Out on!ition hen there is no #oer in Genertin) ttion (rom Tur;o Genertor n! lso not (rom )ri!,in this con!ition to su##ly the emer)ency eMui#ment,li%e scnner (n,$F/,ID Fn,el Oil /um#,Ele"tion ystem throu)h emer)ency ;or!, e nee! this Diesel Genertor+In e"ery unit there is one DG set n! in cse o( unit 568 n! 56 there is To DG set to su##ly the emer)ency eMui#ment o( tht corres#on!in) unit+The c#city o( DG et t unit 567 n! 56' is 870B2A+
CONCLU!ION Genertion o( Mulity #oer t lo cost ;ein) the #rero)ti"e o( therml #oer #lnt, D2 .T/ ims t usin) ;est technolo)ies throu)h e9#erience! hn!s to #rot;le outcomes hile scorin) #oints on )enerte en"ironmentl s(ety+ Also, trnsmission o( #oer hile %ee#in) s(ety o( )ri! s ell s #oer #lnt t si)ht is mssi"e !uty tht comes t hn! in the hole #rocess o( !istri;ution o( #oer+ These re !one ith utmost cre in D2, .T/ usin) "rious com#onents s !escri;e! in the #re"ious riteu#s+
