FACTS 2 Mark Questions

EE809

Flexibile AC Transmission Systems ELECTRICAL AND ELECTRONICS ENGINEERING EE809 FLEXILE AC TRANS!ISSION S"STE!S SE!ESTER# 08 T(O !AR $ESTIONS AND AND ANS(ERS ANS(ERS

$NIT%I &' ()at is meant by FACTS* FACTS 2e7i1es are ma2e by a27an1e2 ,o-er ele1troni1 1ontrol ei,ments' T)e .exible a1 transmission systems 3FACTS4 6i7e soltions to t)e ,roblems an2 limitations -)i1) -ere intro21e2 in t)e ,o-er system -it) t)e intro21tion o/ ,o-er ele1troni1s base2 1ontrol /or rea1ti7e ,o-er , o-er'' +' ()at is real ,o-er* T)e real real ,o-er .o-s .o-s /rom sor1e sor1e to to loa2' $nit# (atts 3(4 5' ()at are t)e sor1es o/ real ,o-er* All 21 an2 a1 6enerators 6enerators B' ()at is t)e nee2 /or rea1ti7e ,o-er* T)e rea1ti7e ,o-er is essential /or t)e o,eration o/ ele1troma6neti1 ener6y 2e7i1es it ,ro7i2es reire2 1o,lin6 :el2s /or ener6y 2e7i1es' ;' ()at is rea1ti7e ,o-er* T)e rea1ti7e ,o-er .o-s /rom loa2 to sor1e' T)e a7era6e 7ale /or rea1ti7e ,o-er is ' ()at are t)e sor1es o/ rea1ti7e ,o-er* i4 Ca,a1itor ii4 Syn1)ronos 6enerator 3it 1an 6enerate bot) real an2 rea1ti7e ,o-er4 ?' !ain ob@e1ti7es o/ FACTS* i4 T)e ,o-er trans/er 1a,ability o/ transmission system is to be in1rease2' ii4 T)e ,o-er .o- is to be e,t o7er 2esi6nate2 rotes'

EE809

Flexibile AC Transmission Systems

8' ()o im,lemente2 t)e FACTS 1on1e,t* For -)at* T)e 1on1e,t o/ FACTS -as :rst 2e:ne2 in &988 by N'G'in6orani' It 1ontrols t)e interrelate2 ,arameters -)i1) are in7ol7e2 in ,o-er system o,eration s1) as series an2 s)nt im,e2an1e 1rrent 7olta6e an2 ,)ase an6le' Also it 2am,s t)e os1illations at 7arios /reen1ies belo- t)e rate2 /reen1y' 9' ()at are t)e ty,es o/ FACTS 2e7i1es* S=C TCSC

% Stati1 =ar Com,ensator % T)yristor Controlle2 Series Ca,a1itor

$FC

% $ni:e2 o-er Flo- Controller

IFC

% Interline o-er Flo- Controller

SSSC

% Stati1 Syn1)ronos Series Com,ensator

SSC

% Stati1 Syn1)ronos Com,ensator 3STATCO!4

&0' ()at are t)e ty,es o/ FACTS 1ontrollers* i4 Series 1ontroller ii4 S)nt 1ontroller iii4 Combine2 series%series 1ontrollers i74 Combine2 series%s)nt 1ontrollers &&' ()ere t)e :rst STATCO! -as im,lemente2* Tennesee =alley At)ority3T=A4 installe2 t)e :rst stati1 syn1)ronos 1om,ensator 3STATCO!4 in &9;; to stren6t)en transmission line ties bet-een its Slli7an sbstation an2 t)e rest o/ its net-or' It re21es t)e nee2 o/ a22itional trans/ormer ban an2 a7oi2in6 more labors' &+' ()ere t)e :rst $FC -as im,lemente2* In &998 installation o/ t)e :rst ni:e2 ,o-er .o- 1ontroller 3$FC4 -as 1om,lete2 at t)e Ine< Sbstations o-ne2 by Ameri1an Ele1tri1al o-er 3AE4' It re,resents t)e :rst 1ontroller 1a,able o/ ,ro7i2in6 1om,lete 1ontrol o/ all t)e t)ree basi1 transmission system ,arameters t)at is 7olta6e line im,e2an1e ,)ase an6le' &5' (rite 2o-n t)e a27anta6es o/ FACTS' i4 It 1ontrols line im,e2an1e an6le an2 7olta6e -)i1) )el,s in 1ontrollin6 t)e ,o-er

EE809

Flexibile AC Transmission Systems .o- in transmission lines' ii4 T)e ,o-er .o- in t)e transmission lines 1an be ma2e o,timm' iii4 It )el,s in 2am,in6 ot t)e os1illations an2 a7oi2s 2ama6e o/ 7arios ei,ments' i74 It limits t)e im,a1ts o/ /alts an2 ei,ment /ailres'

&B' De:ne rea1ti7e ,o-er 1ontrol' To mae transmission net-ors o,erate -it)in 2esire2 7olta6e limits met)o2s o/ main6 , or tain6 a-ay rea1ti7e ,o-er is 1alle2 rea1ti7e ,o-er 1ontrol' &;' ()at is t)e rea1ti7e ,o-er 7ale H /or ele1troma6neti1 2e7i1es* Ele1troma6neti1 2e7i1es store ener6y in t)eir ma6neti1 :el2s' T)ese 2e7i1es 2rala66in6 1rrent t)ere by resltin6 in ,ositi7e 7ales o/  t)ere/ore t)ey are /reently re/erre2 to as t)e absorbers o/ rea1ti7e ,o-er' &>' ()at is t)e rea1ti7e ,o-er 7ale H /or ele1trostati1 2e7i1es* Ele1trostati1 2e7i1es store ener6y in t)eir ele1tri1 :el2s' T)ese 2e7i1es 2ra- lea2in6 1rrent an2 reslt in a ne6ati7e 7ale o/ H t)s t)ey are seen to be s,,liers o/ rea1ti7e ,o-er' &?' ()at is rea1ti7e ,o-er 1om,ensation* Com,ensators* Rea1ti7e ,o-er 1ontrol /or a transmission line is o/ten 1alle2 rea1ti7e ,o-er 1om,ensation' External 2e7i1es or sb systems t)at 1ontrol rea1ti7e ,o-er on transmission line are no-n as 1om,ensators' &9' ()at is s)nt 1om,ensation* T)e S)nt 1om,ensators are 1onne1te2 ,arallel to t)e transmission lines -it) t)e )el, o/ Cir1it breaers' S)nt rea1tors 1om,ensate /or t)e line 1a,a1itan1e an2 t)ey 1ontrol o7er 7olta6es at no loa2s an2 li6)t loa2 1on2itions' T)e s)nt 1om,ensators nee2 1are/l system 2esi6n be1ase o/ )i6) 1)ar6in6 in%rs) 1rrents' +0' ()at is series 1om,ensation* T)e Series 1om,ensators are 1onne1te2 series -it) t)e transmission lines' Series 1om,ensators are se2 to ,artially oJset t)e eJe1ts o/ t)e series in21tan1es o/ transmission lines' It ,ro7i2es atomati1 a2@stment o/ rea1ti7e ,o-er 1om,ensation' +&' ()at are t)e 2esi6n /a1tors 1onsi2ere2 /or t)e series 1om,ensators* i4T)e 7olta6e ma6nit2es a1ross t)e 1a,a1itor ban

EE809


ii4 T)e /alt 1rrents at t)e terminals o/ a 1a,a1itor ban iii4 T)e /alt 1rrents at t)e terminals o/ a 1a,a1itor ban i74 T)e ,la1ement o/ s)nt rea1tors in relation to t)e series 1a,a1itors ++' ()at are t)e met)o2s se2 /or 1om,ensatin6 t)e n1om,ensate2 transmission lines* i4 Loa2 1om,ensation% One 1a,a1itor is 1onne1te2 ,arallel a1ross t)e loa2 ii4 System 1om,ensation % In a22ition -it) t)e ,arallel 1a,a1itor t)e ,o-er tility 2e7i1es are also 1onne1te2' +5' Com,are t)e 1on7entional series 1ontroller -it) t)e a27an1e2 series 1ontroller3IFC4'

Con7entional series 1ontroller

A27an1e2 series 1ontroller3IFC4

&'Loa2 balan1in6 o/ transmission lines is 7ery &' It )as better loa2 balan1in6' oor' +' It )as 7ery lo- XKR ratio'

+' It )as )i6) XKR ratio'

5' Transmission line losses are 7ery )i6)'

5' Transmission line losses are lo-'

B' It 1ontrols bot) real an2 rea1ti7e ,o-er -it) B' It 1ontrols bot) real an2 rea1ti7e ,o-er -it) lo- o,eratin6 e1ien1y' )i6) o,eratin6 e1ien1y'

EE809

Flexibile AC Transmission Systems $NIT%II

&' S)ort notes on 7olta6e 1ontrol by S=C* T)e transmission line 7olta6e is maintaine2 by 1onne1tin6 stati1 7ar 1om,ensator 3S=C4 in t)e re1ei7in6 en2 si2e' T)e 1om,arator -ill measre t)e a1tal an2 re/eren1e 7ales o/ transmission line 7olta6e 2e,en2s on t)e 1om,arator ot,t t)e rea1ti7e ,o-er is in@e1te2 into t)e transmission line an2 t)e transmission line 7olta6e -ill be 1ontrolle2' +' (rite 2o-n t)e eation /or S=C bs 7olta6e' =S M =S=C  IS=C XS 5' Gi7e t)e a27anta6es o/ t)e slo,e in t)e S=C 2ynami1 1)ara1teristi1s' i4 T)e rea1ti7e ,o-er ratin6 is re21e2 ii4 S=C is ,re7ente2 /rom rea1)in6 its rea1ti7e ,o-er limit too /reently iii4 It ,ro7i2es eJe1ti7e ,arallel o,eration o/ t-o ,arallel 1onne1te2 S=Cs B' ()at is S=C slo,e in t)e 2ynami1 1)ara1teristi1s* To im,ro7e t)e ,o-er system o,eratin6 ,er/orman1e +'; 7olta6e 2e%re6lation -ill be ,ro7i2e2 in S=C o,eration' So t)is 7olta6e 2e%re6lation reslts in ; slo,e in t)e S=C 2ynami1 1)ara1teristi1s' ;' o- t)e S=C ,re7ents t)e rea1ti7e ,o-er ratin6 rea1)in6 its limit too /reently* De to slo,e in t)e S=C 2ynami1 1)ara1teristi1s t)e no loa2 to 1)an6e in loa2 7ariation limit -ill be in1rease2 so t)e S=C is ,re7ente2 /rom rea1)in6 its rea1ti7e ,o-er limit too /reently' T)s t)e total rea1ti7e ,o-er nee2e2 is re21e2 to 1ertain limit' >' Ex,lain t)e loa2 s)arin6 o/ t-o ,arallel 1onne1te2 S=Cs' (it)ot slo,e in t)e S=C 2ynami1 1)ara1teristi1s t)ere is a 2is1ontinos 6a, bet-een 1a,a1iti7e an2 in21ti7e re6ion' T)is 6a, -ill be re21e2 by o,eratin6 t-o ,arallel 1onne1te2 S=Cs -it) slo,e 3+'; 7olta6e 2e%re6lation4 in t)e S=C 2ynami1 1)ara1teristi1s' ?' ()at are t)e 1on2itions in7ol7e2 /or in.en1e o/ t)e S=C on system 7olta6e* i4 Co,lin6 trans/ormer i6nore2 ii4 (it) 1o,lin6 trans/ormer iii4 System 6ain

EE809


8' ()at is ESCR* EJe1ti7e s)ort 1ir1it ratio 3ESCR4 M& K XS M & K 3%Ps71 K PIs714 M S3ei7alent system ss1e,tan1e4 9' ()at is system 6ain* System 6ain  N M =s K ESCR M =s K S &0' ()at is ,er nit system 6ain* er nit System 6ain  N M P=s71 K s71 M s71 K S1 ,' &&' ()at is s)ort 1ir1it ,o-er* S)ort 1ir1it ,o-er S 1 M 3 base 7olta6e4Q3s)ort 1ir1it 1rrent4 M 3=b 4 Q 3 S' =s4 &+' ()at is S!I system* A sin6le syn1)ronos 6enerator 1onne1te2 -it) more nmber o/ transmission lines in ele1tri1 ,o-er system is 1alle2 sin6le ma1)ine in:nite bs 3S!I4 system' &5' ()at are t)e 2iJerent 1ases in7ol7e2 in ,o-er an6le 1r7es o/ a S!I system* i4 n1om,ensate2 1ase ii4 i2eal mi2,oint S=C nlimite2 ratin6 3s71  B max4 iii4 :xe2 1a,a1itor 1onne1te2 at its mi2,oint i74 mi2,oint S=C -it) limite2 ratin6 3s71 M +max4 &B' ()at is t)e ob@e1ti7e o/ S=C en)an1ement in transient stability* An S=C si6ni:1antly en)an1es t)e ability to maintain syn1)ronism o/ a ,o-er system t)at is 1ontrolle2 an2 1o%or2inate2 system e7en -)en t)e system is sb@e1te2 to lar6e s22en 2istrban1es' So t)e S=C en)an1ement in transient stability ,ro7i2es stea2y ,o-er trans/er in transmission lines'

EE809


&;' ()at is syn1)roni' ()at is S=C ss1e,tan1e* Ss1e,tan1e S M3 1K x1 4 % 3i K xi4 ()ere xi % total in21ti7e rea1tan1e o/ t)e S=C x1 % total 1a,a1iti7e rea1tan1e o/ t)e S=C i % t)e 1on21tin6 /ra1tion o/ TCR 1 % t)e 1on21tin6 /ra1tion o/ TSC &?' (rite 2o-n t)e eation /or syn1)roni
EE809


$NIT%III &' ()at is meant by TCSC* TCSC is a t)yristor 1ontrolle2 series 1a,a1itor' It )as one ,arallel 1onne1te2 t)yristor 1ontrolle2 in21tor an2 a series 1a,a1itor 1onne1te2 -it) t)e transmission line' It ,ro7i2es 1ontinos 7ariable 1a,a1iti7e rea1tan1e an2 7ariable in21ti7e rea1tan1e to 1ontrol t)e transmission line ,arameters' +' (rite 2o-n t)e ex,ression /or ei7alent im,e2an1e o/ a TCSC' Ei7alent im,e2an1e o/ a TCSC Ue M %@ 33&4 K 3V1%&K VL44 5' ()at is t)e 1on2ition /or 7ariable 1a,a1iti7e rea1tan1e in a TCSC* I/ 3V1 % 3&K VL44 W 0 % t)e TCSC ,ro7i2es 7ariable 1a,a1iti7e rea1tan1e mo2e' B' ()at is t)e 1on2ition /or 7ariable in21ti7e rea1tan1e in a TCSC* I/ 3V1 % 3&K VL44  0 % t)e TCSC ,ro7i2es 7ariable in21ti7e rea1tan1e mo2e' ;' ()at are t)e 2iJerent mo2es o/ o,eration o/ TCSC* i4 y,asse2% t)yristor mo2e ii4 lo1e2 % t)yristor mo2e iii4 artially 1on21tin6 t)yristor or =ernier mo2e >' Gi7e s)ort notes on y,asse2% t)yristor mo2e' In t)is mo2e t)e TCSC mo2le be)a7es lie a ,arallel 1a,a1itor % in21tor 1ombination' T)e ss1e,tan1e3in1rease in ,o-er .o-4 7ale o/ in21tor is )i6)er t)an t)e 1a,a1itor' T)is mo2e is em,loye2 /or 1ontrol ,r,oses an2 initiatin6 1ertain ,rote1ti7e /n1tions' ?' Gi7e s)ort notes on lo1e2 % t)yristor mo2e' In t)is mo2e also no-n as t)e -aitin6 mo2e )ere t)e :rin6 ,lses o/ t)yristor s-it1)es are blo1e2' T)e TCSC be)a7es lie a :xe2 series 1a,a1itor an2 t)e net TCSC rea1tan1e is 1a,a1iti7e' In t)is mo2e t)e 21%oJset 7olta6es o/ t)e 1a,a1itors are monitore2 an2 i1ly 2is1)ar6e2 sin6 a 21%oJset 1ontrol -it)ot 1asin6 any )arm to t)e transmission system trans/ormers' 8' Gi7e s)ort notes on 1a,a1iti7e =ernier mo2e' In t)is mo2e t)e TCSC ,ro7i2es 1ontinosly 1ontrollable 1a,a1iti7e rea1tan1e' It is a1)ie7e2 by 7aryin6 t)e t)yristor ,air :rin6 an6le in an a,,ro,riate ran6e' A 7ariant o/ t)is mo2e

EE809


is t)e 1a,a1iti7e 7ernier mo2e in -)i1) t)e t)yristors are :re2 -)en t)e 1a,a1itor 7olta6e an2 1rrent )a7e o,,osite ,olarity' T)is 1on2ition 1ases a t)yristor 1ontrolle2 rea1tor 3TCR4 1rrent t)at )as a 2ire1tion o,,osite t)at o/ t)e 1a,a1itor 1rrent t)ereby resltin6 in a loo,%1rrent .oin t)e TCSC 1ontroller' T)is loo, 1rrent in1reases t)e 7olta6e a1ross t)e :xe2 1a,a1itor 3FC4 9' Gi7e s)ort notes on in21ti7e =ernier mo2e' eJe1ti7ely en)an1in6 t)e ei7alent 1a,a1iti7e rea1tan1e an2 t)e series 1om,ensation le7el' In t)is mo2e t)e TCSC ,ro7i2es 1ontinosly 1ontrollable in21ti7e rea1tan1e' ere t)e TCSC 1an be o,erate2 by )a7in6 a )i6) le7el o/ t)yristor 1on21tion' In t)is mo2e t)e 2ire1tion o/ t)e 1ir1latin6 1rrent is re7erse2 an2 t)e 1ontroller ,resents a net in21ti7e im,e2an1e' &0' ()at are t)e 1on1lsions ma2e /rom t)e TCSC mo2es o/ o,eration* i4 T)yristor s-it1)e2 series 1a,a1itor 3TSSC4 -)i1) ,ermits a 2is1rete 1ontrol o/ t)e 1a,a1iti7e rea1tan1e' ii4 T)yristor 1ontrolle2 series 1a,a1itor 3TCSC4 -)i1) oJers a 1ontinos 1ontrol o/ 1a,a1iti7e or in21ti7e rea1tan1e' ra1ti1ally TSSC is more 1ommonly se2' &&' ()at are t)e mo2elin6 te1)nies in7ol7e2 in TCSC* i4=ariable rea1tan1e mo2el 3&' Transient stability mo2el +' Lon6 term stability mo2el4 ii4An a27an1e2 transient stability st2ies mo2el &+' ()at is t)e nee2 /or mo2elin6 o/ a TCSC* A TCSC in7ol7es 1ontinos % time 2ynami1s relatin6 to 7olta6es an2 1rrents in t)e 1a,a1itor an2 rea1tor an2 nonlinear 2is1rete s-it1)in6 be)a7ior o/ t)yristors' So it is 7ery im,ortant to 2eri7e a mo2el /or a TCSC 1ontroller to maintain t)e stability o/ a ,o-er system' &5' Gi7e s)ort notes on 7ariable rea1tan1e mo2el' It is a asi%stati1 a,,roximation mo2el' T)is mo2el ,ro7i2es mltimo2e TCSC 1on:6ration t)at is t)e 2is1ontinity 6a, bet-een in21ti7e an2 1a,a1iti7e re6ions are re21e2 by ,ro7i2in6 1ontinos rea1tan1e ran6e' T)is mo2el is 6enerally se2 /or inter%area mo2e analysis an2 it ,ro7i2es )i6) a11ra1y -)en t)e rea1tan1e boost /a1tor is less t)an &';' &B' ()at is rea1tan1e boost /a1tor o/ a TCSC mo2el* Rea1tan1e boost /a1tor M X TCSC K XC

EE809


&;' (rite s)ort notes on Transient stability mo2el' In t)e 7ariable rea1tan1e mo2el /or stability st2ies a re/eren1e 7ale o/ TCSC rea1tan1e Xre/  is 6enerate2 /rom t)e ,o-er s1)e2lin6 1ontroller base2 on t)e ,o-er .os,e1i:1ation in t)e transmission lines' T)en X re/ is 1on7erte2 into X total -it) t)e )el, o/ mo2lation 1ontroller 2elay 1ir1it la6 1ir1it Xax si6nal an2 X:xe2 si6nals' Finally t)e reire2 Xtotal 1ontrol 7ale -ill be 1on7erte2 into ,er nit 7ale an2 it ,ass t)ro6) t)e 1ontrol nit' &>' (rite 2o-n t)e TCSC base rea1tan1e 7ale' TCSC base rea1tan1e Ubase M 3= TCSC4+ K !=Asys ()ere = TCSC % rms line % line 7olta6e o/ t)e TCSC in = !=Asys % 5,)ase !=A base o/ t)e ,o-er system &?' ()at is lon6 term stability mo2el* T)e 1a,ability 1r7es o/ t)e TCSC 2e,en2 on t)e 2ration /or -)i1) t)e 7olta6e an2 1rrent o,eratin6 1on2itions ,ersist 3ee, on 1ontine24 o/ t)e TCSC' For lon6 term 2ynami1 simlation an o7er loa2 mana6ement /n1tion nee2s to be in1or,orate2 in t)e 1ontrol system' It 2etermines t)e a,,ro,riate TCSC o7erloa2 ran6e /or -)i1) it mo2i:es t)e X max limit an2 Xmin limit ' It t)en a,,lies t)e same mo2i:1ations to t)e 1ontroller' T)is mo2el is se2 -i2ely in 1ommer1ial stability ,ro6rams be1ase o/ its sim,li1ity an2 it is also se2 /or system ,lannin6 st2ies as -ell as /or initial in7esti6ations o/ t)e eJe1ts o/ t)e TCSC in 2am,in6 ,o-er os1illations' &8' ()at is t)e se o/ a27an1e2 transient stability st2ies mo2el* T)is mo2el is se2 to sol7e t)e TCSC time 7aryin6 2ynami1s -it) t)e )el, o/ 2iJerential eations' It 1al1lates t)e 1a,a1itor 7olta6e 1a,a1itor 1rrent in21tor 7olta6e an2 in21tor 1rrent /or e7ery )al/ 1y1le o/ ; % re4 K +4+4 Inte6ral 1ontroller 6ain  i M %+5%+B ex, 3 3re %>;4 K +4 +0' ()at is t)e nee2 /or im,ro7ement in t)e TCSC system stability limit* In a ,o-er system 2e to 1riti1al /alts t)e lar6e 7olme o/ ,o-er ten2s to .o- in ,arallel ,at)s o/ a transmission lines it -ol2 1reate se7ere o7erloa2 1on2ition' T)e 1on7entional :xe2%series 1om,ensation on t)e ,arallel ,at)s o/ a transmission line ,ro7i2es t)e soltion /or t)e abo7e ,roblem bt it in1reases t)e total system losses' T)ere/ore it is

EE809


a27anta6eos to install a TCSC in ey transmission ,at)s -)i1) ,ro7i2es series 1om,ensation a11or2in6 to t)eir system reirements -it) lo-er system losses' So t)e im,ro7ement in t)e TCSC system stability limit -as 7ery im,ortant in ,o-er system' +&' ()at are /n1tions o/ 2am,in6 1ontroller* i4 It stabili
EE809

Flexibile AC Transmission Systems ii4 T)e rotor%an6leKs,ee2 3/reen1y4 2iJeren1e a1ross t)e system iii4 T)e real ,o-er .o- on a2@a1ent transmission lines

EE809


$NIT% I= &' ()at is meant by 1ontrollers* T)e /a1ts 1ontrollers ex1)an6e t)e rea1ti7e ,o-er to t)e transmission lines -it) t)e )el, o/ ,)ase s)i/tin6 te1)nies' I/ nee2e2 t)e real ,o-er is also s,,lie2 in a22ition to t)e rea1ti7e ,o-er in to t)e transmission line -it) t)e )el, o/ emer6in6 FACTS 2e7i1es s1) as STATCO! an2 $FC' ere t)e nee2 o/ lar6e si
im,a1t'

iii4 It ses en1a,slate2 ele1troni1 1on7erters t)ereby minimi
;' Gi7e 2etails abot :rst installe2 STATCO! 2e7i1e at Slli7an Sb%station' Tennessee =alley At)ority 3T=A4 installe2 t)e :rst Y &00 !=A STATCO! in &99; at its Slli7an sbstation'

EE809


>' ()at are t)e a,,li1ations o/ :rst installe2 STATCO! 2e7i1e at Slli7an Sb% station* T)e a,,li1ation o/ t)is STATCO! is ex,e1te2 to re21e t)e T=As nee2 /or loa2 ta, 1)an6in6 trans/ormers t)ere by a1)ie7in6 sa7in6s by minimi
EE809


&+' ()y t)e 1on7erters 3STATCO!4 absorb t)e small amont o/ real ,o-er /rom t)e a1 system* T)e 1on7erter absorbs t)e small amont o/ real ,o-er /rom t)e a1 system to meet its internal losses an2 ee, t)e 1a,a1itor 3ener6y stora6e 2e7i1e4 7olta6e at t)e 2esire2 le7el' &5' (rite s)ort on $FC' T)e ni:e2 ,o-er .o- 1ontroller 3$FC4 is t)e most 7ersatile FACTS 1ontroller 2e7elo,e2 so /ar -it) all en1om,assin6 o/ 7olta6e re6lation series 1om,ensation an2 ,)ase s)i/tin6' It 1an in2e,en2ently an2 7ery ra,i2ly 1ontrol bot) real an2 rea1ti7e ,o-er .o-s in a transmission line' &B' ()at are t)e /n1tions o/ series 1on7erter in t)e $FC* In a $FC series 1on7erter ex1)an6es bot) real an2 rea1ti7e ,o-er -it) t)e transmission line' Alt)o6) t)e rea1ti7e ,o-er is internally 6enerate2 or absorbe2 by t)e series 1on7erter t)e real ,o-er 6eneration or absor,tion is ma2e /easible by t)e 21 ener6y stora6e 2e7i1e' &;' ()at are t)e /n1tions o/ s)nt 1on7erter in t)e $FC* In a $FC s)nt 1on7erter mainly se2 to s,,ly t)e real ,o-er 2eman2 o/ series 1on7erter -)i1) it 2eri7es /rom t)e transmission line itsel/' T)e s)nt 1on7erter maintains 1onstant 7olta6e o/ t)e 21 bs' In a22ition t)e s)nt 1on7erter /n1tions lie a STATCO! an2 in2e,en2ently re6late t)e terminal 7olta6e o/ t)e inter1onne1te2 bs by 6eneratin6 or absorbin6 a reisite amont o/ rea1ti7e ,o-er' &>' ()at are t)e o,eratin6 7ariable 1onstraints o/ $FC* i4 T)e series in@e1te2 7olta6e ma6nit2e ii4 T)e line 1rrent t)ro6) series 1on7erter iii4 T)e s)nt 1on7erter 1rrent i74 T)e maximm line si2e 7olta6e o/ t)e $FC =4 T)e minimm line si2e 7olta6e o/ t)e $FC 7i4 T)e real ,o-er trans/er bet-een t)e series 1on7erter an2 t)e s)nt 1on7erter &?' ()at -as t)e reslt o/ 1ase st2y o/ an $FC at &00 miles len6t) transmission line ,o-er system*

EE809


In t)at 1ase st2y o/ a &00 miles lon6 t-o area mo2el transmission line t)e 5Z to 6ron2 /alt )as been a,,lie2 /or times t)en 2is1onne1te2' T)e reslt in2i1ates t)at -it) $FC t)e ,o-er trans/er is 5;? !( -it)ot $FC t)e ,o-er trans/er is &?> !(' T)s t)e ,o-er trans/er -ill be in1rease2 -it) t)e )el, o/ an $FC' &8' ()at -as t)e eJe1t o/ 2am,in6 by sin6 $FC in 1ase st2y ,o-er system transmission lines* In t)at 1ase st2y o/ a &00 miles lon6 t-o area mo2el transmission line t)e 5Z to 6ron2 /alt )as been a,,lie2 /or times t)en 2is1onne1te2' T)e reslt in2i1ates t)at -it) $FC t)e ,o-er trans/er is 5;? !( -it)ot $FC t)e ,o-er trans/er is &?> !(' T)s t)e ,o-er trans/er -ill be in1rease2 -it) t)e )el, o/ an $FC' Also t)e os1illations in t)e transmission line -ill be 2am,e2 by $FC' T)at is -it) $FC t)e os1illation ran6e -ill be %&B !( to %&; !( ,er se1on2 bt -it)ot $FC t)e os1illation ran6e -ill be %9 !( to %+& !( ,er se1on2'

EE809


$NIT%= &' ()at is meant by 1ontroller intera1tions* I/ t-o or more FACTS 2e7i1es are 1onne1te2 in same transmission line t)en t)e o,eratin6 7ariables bet-een t)em mst )a7e better 1o%or2inate2 t)at is 1alle2 1ontroller intera1tion' I/ FACTS 2e7i1es are not 1o%or2inate2 it 1reates n-ante2 os1illation in t)e transmission lines' +' ()at are t)e ty,es o/ 1ontroller intera1tions* i4 !lti,le FACTS 1ontroller o/ a similar in2 ii4 !lti,le FACTS 1ontroller o/ a 2issimilar in2 iii4 !lti,le FACTS 1ontrollers an2 =D= 1on7erter 1ontrollers 5' ()at are t)e /reen1ies ran6es o/ 1ontroller intera1tions* i4 0 < /or stea2y state intera1tions ii4 0 % 5K; < /or ele1trome1)ani1al os1illations iii4 + % &; < /or small si6nal or 1ontrol os1illation i74 &0 % ;0K>0 < /or sb syn1)ronos resonan1e 3SSR4 intera1tion 74  &; < /or ele1troma6neti1 transients )i6) % /reen1y resonan1e or )armoni1 resonan1e intera1tions an2 net-or resonan1e intera1tions B' ()at is meant by stea2y state intera1tion* Stea2y%state intera1tions bet-een 2iJerent 1ontrollers 3FACTS%FACTS or FACTS% =DC4 o11r bet-een t)eir system relate2 1ontrols' T)ey are stea2y state in natre an2 2o not in7ol7e any 1ontroller 2ynami1s' T)ese intera1tions are relate2 to isses s1) as t)e stability limits o/ stea2y state% state 7olta6e an2 stea2y%state ,o-er in1l2e2 are e7alations o/ t)e a2ea1y o/ rea1ti7e%,o-er s,,ort at bses system stren6t) an2 so on' E64 Stea2y state 7olta6e 1ontrol FACTS%=DC a1 7olta6e re6lation' ;' ()atbet-een is t)e analysis met)o2/or se2 to 2etermine t)e stea2y state intera1tion* To 2etermine t)is intera1tion Loa2%Flo- an2 Stability ,ro6rams are se2' >' ()at is meant by ele1trome1)ani1al os1illation intera1tion* Ele1trome1)ani1al os1illation intera1tion bet-een FACTS 1ontrollers in7ol7e syn1)ronos 6enerators 1om,ensator ma1)ines an2 asso1iate2 ,o-er system stabili
EE809


T)e os1illations in1l2e lo1al mo2e os1illations ty,i1ally in t)e ran6e o/ 0'8 % + < an2 inter% area mo2e os1illations ty,i1ally in t)e ran6e o/ 0'+ % 0'8 <' T)e lo1al mo2e is 1ontribte2 by syn1)ronos 6enerators in a ,lant or se7eral 6enerators lo1ate2 in 1lose 7i1inity t)e inter% area mo2e reslts /rom t)e ,o-er ex1)an6e bet-een ti6)tly 1o,le2 6enerators in t-o areas line2 by -ea transmission lines' ?' ()at is t)e analysis met)o2s se2 to 2etermine t)e ele1trome1)ani1al os1illation intera1tion* To 2etermine t)is intera1tion ei6en 7ale analysis ,ro6rams are se2' 8' ()at is meant by 1ontrol or small si6nal os1illation intera1tions* Controller intera1tions bet-een in2i7i2al FACTS 1ontrollers an2 t)e net-or or bet-een FACTS 1ontrollers an2 =DC lins may lea2 to t)e onset o/ os1illations in t)e ran6e o/ + % &; <' T)ese os1illations are lar6ely 2e,en2ent on t)e net-or stren6t) an2 t)e 1)oi1e o/ FACTS 1ontroller ,arameters an2 t)ey are no-n to reslt /rom t)e intera1tion bet-een 7olta6e 1ontrollers o/ mlti,le S=Cs t)e series resonan1e bet-een series 1a,a1itors an2 s)nt rea1tors in t)e /reen1y ran6e o/ B % &; < an2 so /ort)' T)e emer6en1e o/ t)ese os1illations 9' ()at are t)e analysist)e met)o2s to 2etermine si6ni:1antly in.en1es tnin6 se2 o/ 1ontroller 6ain' t)e 1ontrol or small si6nal os1illation intera1tion* T)ese )i6) /reen1y os1illation intera1tions are 2etermine2 by /reen1y s1annin6 ,ro6rams ele1troma6neti1 transient ,ro6rams 3E!Ts4 )ysi1al simlators an2 ei6en 7ale analysis ,ro6rams' &0' ()at is meant by sb syn1)ronos resonan1e intera1tions* Sb syn1)ronos os1illations may be 1ase2 by t)e intera1tion bet-een t)e 6enerator torsional system an2 t)e series 1om,ensate2 transmission lines t)e =DC 1on7erters t)e 6enerator ex1itation 1ontrol or e7en t)e S=Cs' T)eses os1illations sally in t)e /reen1y ran6e o/ &0 % ;0K>0 < 1an ,otentially 2ama6e 6enerator s)a/ts' &&' ()at are t)e analysis met)o2s se2 to 2etermine t)e sb syn1)ronos resonan1e intera1tions* T)ese SSR os1illation intera1tions are 2etermine2 by /reen1y s1annin6 ,ro6rams ele1troma6neti1 transient ,ro6rams 3E!Ts4 )ysi1al simlators an2 ei6en 7ale analysis ,ro6rams' &+' ()at is meant by )i6) /reen1y intera1tion* i6)%/reen1y os1illations in ex1ess o/ &; < are 1ase2 by lar6e nonlinear 2istrban1es s1) as t)e s-it1)in6 o/ 1a,a1itors rea1tors or trans/ormers /or -)i1) reason t)ey

EE809


are 1lassi:e2 as ele1troma6neti1 transients' FACTS 1ontrollers nee2 to be 1o%or2inate2 to minimi

FACTS 2 Mark Questions

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