GLOBAL CONTROL OF POWER SYSTEM FOR TRANSIENT STABILITY ENHANCEMENT AND VOLTAGE REGULATION

Transcription

1 GOA CONRO OF POWR SYSM FOR RANSIN SAIIY NHANCMN AND OAG RGUAION G. H. Zhang Y. Wang Nanyang chnoogica Univrsiy, Singapor, Absrac Goba conro is xn o uncrain powr sysms o mainain h ransin sabiiy an achiv propr pos-au voag. h powr sysm is irs compos ino svra paria mos accoring o irn conro objcivs an opraing sags. hn h irc back inarizaion (DF) chniqu is appi o inariz h paria noninar mos an robus paria conrors ar sign o consir h sysm uncrainis an conror inracions or irn paria mos. Ony oca variabs ar n in h sign o paria conrors. Finay, h goba conro aw is obain by aggrgaing h paria conrors wih mmbrship uncions. h sing-machin inini-bus (SMI) powr sysm wih h SC is us as an xamp sysm o vaua h civnss o h propos goba conro approach. Kywor: Goba conro, ransin sabiiy, voag rguaion INRODUCION h imporanc o powr sysm conro is highigh u o incras uiizaion o h ransmission sysm or which hy ar no origina sign or byon hir origina sign imis. Svra yps o probms which ac conror prormanc ar incrasingy akn ino accoun in h conror sign, spciay or powr sysms unr arg isurbancs. Such as, h noninariis an uncrainis o powr sysm mos; unsirab inracions among muip conrors; irn conro objcivs wihin varying opraing rgions an hir inhrn conicing objcivs. h us o various avanc conro chniqus o sov abov probms in powr sysms sms o b on o promising appicaions aras. Noninariis an uncrainis o sysm mos hav bn ovrcom by noninar back inarizaion chniqus [][] an robus conro hory [3][4]. In mos pracica siuaions, powr sysm consiss o various subsysm associa wih conro, which xpan a vas gographica omain. Som spcia sabiiy conro rquirmns, such as h insananous masurmn rom rmo phasor masurmn unis an rmo an propr inormaion xchangs bwn conrors, ar so inrica ha vn high-capaciy ibr-opica-bas communicaion nwork can no sov [5], cnraiz conro was rquny rsor o mainain a sab sysm wih varying inrconncions an coorina vrsai conrors. In aiions, powr sysms opra in svra irn coniions an coorina irn conro goas, which may hav inhrn conics an n o in a ra-o bwn hs objcivs. wo conro sysms ar viny monsra h conicing conro objcivs uring irn conro sags. On is h ra-o bwn ransin sabiiy nhancmn an goo voag rguaion i ony xciaion conro us [][6][7]. h ohr is rva by anaysis ha h SC voag an amping conro conic ach ohr [8]. Goba conro is a raivy nw concp ha has moiva by pracica sysms usuay opras unr irn coniions an h nsuing conros ar xpc o achiv a s o goas [][9]. Goba conro was irs mpoy o arg sca srss powr sysm by biurcaion anaysis [], an hn coorina ransin sabiiy an voag rguaion accoring o irn opraing coniions []. Sma signa sabiiy was akn ino coun in a powr sysm wih a unii powr ow conror []. Goba robus conro approach was primariy propos o uncrain sysms an succ o appy o an xamp powr sysm in our prvious work [][3]. In his work, h goba conro is xn o mainain h ransin sabiiy an achiv propr pos-au voag o a powr sysm in consiraion o uncrainis an conror inracions. h powr sysm is irs compos ino svra paria mos accoring o irn conro objcivs an opraing sags. hn h DF chniqu is appi o inariz h paria noninar mos an robus paria conrors ar sign o consir h sysm uncrainis an conror inracions or irn paria mos. Finay, h goba conro aw is obain by aggrgaing h paria conrors wih mmbrship uncions. h SMI powr sysm wih h SC is uiiz as an xamp sysm o vaua h civnss o h propos goba conro approach. h rs o h papr is organiz as oows. Scion iscusss h goba conro o h uncrain powr sysms. Dynamic mos o SMI sysm wih SC or ransin sabiiy nhancmn an voag rguaion is givn an goba conror ar sign in Scion 3. h simuaion rsus ar us o monsra h civnss o goba conro schm in Scion 4. Concusions ar rawn in Scion 5. GOA CONRO OF UNCRAIN POWR SYSMS Powr sysms ar highy noninar srucur sysms wih muip conro objcivs, which mainy incu rguaion o voags an rquncy, amping 5h PSCC, ig, -6 Augus 5 Sssion, Papr, Pag

2 osciaions aquay an prsrving synchronism in ac o arg isurbancs. Som unsirab inracions among muip conrors hav bn oun an unr aciv invsigaions sinc mos raiiona powr sysm conrors ar usuay insa cnraiz o srv sing objciv. Goba conro was propos o raiz hos pracicay goba conro objcivs by combining h quaiaiv an quaniaiv knowg o powr sysm hrough som hirarchy. his papr xn i o uncrain powr sysms wih uiizaion o morn noninar conro mhooogis. h goba conro schm appi o h uncrain powr sysms is shown in Figur. 3. Dynamic mo o SMI sysm wih SC h cassica hir-orr gnraor mos us in his papr ar rrr o [][4]. h say sa quaions or powr sysm shown in Figur wih SC can b oun in [4]. (h noaion or h sysm mo is givn in Appnix A.) s m r Figur : An SMI sysm wih SC Figur : Goba conro o uncrain powr sysms h uncrain powr sysm is irs compos ino svra paria mos wih coorinaion rus accoring o irn conro objcivs, opraing sags, conror inracions an goba conro objcivs. hn h irc back inarizaion (DF) chniqu is appi o inariz h paria noninar mos an robus paria conrors ar sign o consir h sysm uncrainis an conror inracions or irn paria mos. Finay, h goba conro aw is obain by aggrgaing h paria conrors wih mmbrship uncions. 3 GOA CONRO OF SMI SYSM WIH SC In his papr, w ocus on h goba conro sign o an SMI sysm wih h SC a h mipoin o h ransmission in shown in Figur. h goba conro objciv is o mainain h ransin sabiiy an achiv propr pos-au voag. Dcnraiz paria conrors ar rspcivy sign or gnraor xciaion an SC o raiz corrsponing conro objcivs, h goba conro is h wigh avrag o paria conrors. In h sign o goba conror, h counracions bwn wo irn conro objcivs, ransin sabiiy an voag rguaion, ar ack by coorina conro rus an mmbrship uncions. Morovr, powr sysm uncrainis an paria conror inracions ar akn ino accoun in h sign o robus paria conrors. h SC ynamic mo can b scrib by [4]. = ( + + ku) () R A hr-bus SC sysm in [3] is us o riv h gnra raion bwn SC an powr sysm. I can rsmb any cas whr powr is ransmi hrough a ransmission in an SC is oca in h mi o h in. 3. Goba conro o gnraor xciaion Sinc h goba conro objciv o gnraion xciaion is o mainain h ransin sabiiy an achiv propr pos-au voag, wo irn paria mos ar us o scrib hos wo opraing sags. In his Scion 3., goba conro o gnraor xciaion was xn o h uncrain sysm mos bas on h rsus o []. 3.. ransin conror o gnraor xciaion h characrisic o gnraor in h SMI sysm ar inariz by DF chniqu is givn by h oowing quaions []. δ = ω D ω () ω = ω ( P Pm ) H H P = P ( ) ( ) + v whr = o /, =, P = P P, m P P v = kcu + o ( )[ ] ω I I a a + [ Q + s ] ω P (3) m o ovrcom h uncrainy probm, such as h paramr changs in an ( ), h srucur chang o ransmission paramrs an unr h aus, h varying racanc o SC, h uncrainis rsu o moing rrors, h gnraor mo wih uncrainy is sabish. h compnsaing aw (3) can b rwrin as oows: a I u = { v + Pm [ Q + s ] ω} k P c 5h PSCC, ig, -6 Augus 5 Sssion, Papr, Pag

3 ( ) P o ω (4) k I c a h irnc bwn (3) an (4) is ha h uncrain paramrs an in (3) ar rpac rspcivy by h known paramrs an ( ) in (4). an ( ) ar h avrag vau o an ( ) rspcivy. h quaion () can b rwrin as oows: P = [ + µ ] P( ) [ ( )] ( ) ( ) ( ) + + µ v + ψ ω (5) whr ψ = [ + µ ]{ Q ( ) } + ; s + µ = ; + = o. + + nos h uncrainy in racanc an. ψ, µ an ar boun. = δ ω P as h Choosing [ ] sas, h inariz uncrainis gnraor mos can b rprsn in h oowing compac orm [4]: = ( A + A) + ( + ) v (6) o sov DF compnsa gnraor mo wih uncrainis (6) invovs soving h agbraic Riccai quaion in [4], whr ais o compos h uncrainis an obain h robus back conro aw can b oun. hror, h paria conror o guaran ransin sabiiy o uncrain gnraor mos can b obain as v = K δ K ω K P (7) δ ω P Sinc [ δ ω P ] ( ) ( ) ( ) ar chosn as sas in ransin conror, ransin sabiiy o h SMI sysm wih SC can b guaran. Howvr, h gnraor rmina voag may say a a irn pos-au sa i h sysm srucur chang ar h au. 3.. oag conror o gnraor xciaion o avoi h unsirab variaions wih h chang o powr sysm srucurs, h noninar vo- ω P as h ag conror choosing [ ] sas hav bn propos in [4] Sinc is a noninar uncion o δ, ω an P, irnia quaion is givn in [4] = ω P ( ) ( ) + v v (8) whr an ar highy noninar uncions o δ, P an. Sinc hy ar pnn on h opraing rgion, hir boun ar rgar as h uncrainis in h conror sign. h uncrainis o an ( ) can b consir sam as in h paria mo o ransin conror. Choosing [ ω P ] = as h sas, h inariz uncrainis gnraor mos can b rprsn in h oowing compac orm: = ( A + A) + ( + ) v (9) o sov DF compnsa gnraor mo wih uncrainis (9) invovs soving h agbraic Riccai quaion in [4], whr ais o compos h uncrainis an obain h robus back conro aw can b oun. hror, h paria conror o rgua voag o uncrain gnraor mo can b obain as v = K K K P () ω v v ω p Sinc [ ω P ] ( ) ( ) ( ) ar chosn as sas in paria conror, h gnraor rmina voag can b rgua aroun crain opraing coniions. Howvr, roor ang o gnraor may no mainain is nomina vau in pos-au sa i h sysm srucur chang. I has bn obsrv ha h opraing changs caus by h voag rguaion wi gra h ransin sabiiy o h sysm [] Goba conro o gnraor xciaion o sov h inhrn conicing bwn ransin sabiiy nhancmn an voag rguaion, h mmbrship uncions hav bn succssuy appi o characriz h opraing rgions an raiz h goba conro objciv. h mmbrship uncions [] shown in Figur 3 ar us in his work: µ ( z ) = ( G ) + xp( ( z G )) xp( ( z + G )) µ ( ) = µ () δ z G whr z = α ( ω) + α ( ) () G an α an α ar posiiv sign consans proviing appropria scaing accoring o h snsiiv r- quirmn o powr rquncy an voag. Sinc voag conror is civ whi z is smar han, G h paramr α shou b sma nough o rach his rquirmn. On h ohr si, h paramr α is xpc o b arg nough o mak z argr han. G µ µ δ Figur 3: Mmbrship uncions In h goba conro o gnraor xciaion, mmbrship uncions () ynamicay pariion h who opraing rgion ino wo subspacs, whr paria conrors or ransin sabiiy nhancmn an voag rguaion uncion rspcivy. In opraing rgion o ransin sabiiy, h ra xciaion conro o gnraor is u ( ) obain rom h back conro aw v 5h PSCC, ig, -6 Augus 5 Sssion, Papr, Pag 3

4 (7) hrough compnsaing aw (4). On h ohr han, h ra xciaion conro in opraing rgion o voag rguaion is u obain rom h back conro v aw () hrough compnsaing aw. hror, h goba conror is wigh avrag o h paria conrors an h xciaion conro inpu v aks h orm: v = µ ( zg ) u v + µ δ ( zg ) u (3) h mos appaing abiiy o mmbrship uncions is ha hy auomaicay an smoohy inrpoa h wo paria conrors irrspciv o au squncs an ocaions. I is qui suiab or h pracica rquirmns o goba conro objcivs. 3.3 Goba conro o SC h conro o SC or voag rguaion an amping is a simiar conic happn in h conror sign o h gnraor xciaion. W appi h goba conro approach o h SC o improv ransin sabiiy an achiv propr voag v in h pos-au sa SC ransin conror Sinc h ynamic mo o SC () is a irs orr inar quaion, h oowing back conro aw in [4] is chosn o mainain sabiiy: u = K K ω ω (4) whr ω is h raiv sp a h SC bus. K an K ω can b sign by po pacmn mho SC voag conror h ynamic bhavior o h simp hr-bus SC sysm can b inariz by h DF chniqu in a sa spac orm [3]: (5) = v ( ) C S R whr an S R rprsn h racanc o h ransmission ins, is h SC bus voag, v is h nw conro inpu. h noninar back conro aw can b obain: C R R (6) u = v + ( ) k i k k i Consiring h paramr changs in, R, h SC mo (5) bcoms as oow: an = ( A + A) + ( + ) v (7) o sov DF compnsa SC mo wih uncrainis (7) invovs soving h agbraic Riccai quaion in [3], whr ais o compos h uncrainis an obain h robus back conro aw can b oun. hror, h paria conror o rgua voag o uncrain SC mo can b obain as v = Kv Kv (8) Ony h SC paramrs an h boun o sysm paramrs hav o b known in h sign o h noninar SC voag conror. xac paramrs o ransmission ins ar no rquir. Sysm paramrs an sysm opraing poins ar ra as h uncrainis an han by h robus conro approach Goba conro o SC Simiar wih h goba conro o gnraor xciaion, h mmbrship uncions () ar us o pariion h who opraing rgions o SC ino wo pars. h voag an h raiv sp ω a h SC bus ar chosn as h inpu o mmbrship uncions an z = α ( ω ) + α ( ) (9) SC In opraing rgion o ransin sabiiy, h conro inpu o is u obain rom h back conro aw (4). On h ohr han, h conro inpu in opraing rgion o voag rguaion is u obain rom h back conro aw (8) hrough compnsaing aw (6). hror, h goba conror is wigh avrag o h paria conrors an h conro inpu u aks h orm: SC usc = µ ( zsc ) u + µ δ ( zsc ) u () Mmbrship uncions wi auomaicay an smoohy inrpoa h wo paria conrors or ransin sabiiy nhancmn an voag rguaion irrspciv o au squncs an ocaions. hus, i is convnin or goba conro schm o raiz h wo pracica uncions o SC, amping osciaion in ac o arg isurbancs an proviing h voag suppor. 3.4 Goba conro o h SMI sysm wih SC o his poin, our paria conrors or irn conro objcivs hav bn sign sparay. Ony oca masurmns ar us or ach paria conror. From abov sign procurs, h paria conrors or gnraor an h SC ar inpnn o ach ohr sinc h inrconncions bwn hm ar ra as h paramr uncrainis by h robus conro approach. hror, h goba conro o h SMI sysm wih SC or ransin sabiiy nhancmn an voag rguaion can b monsra in Figur 4, whr our pars in ash rcang rprsn our paria conrors. u u v v v [ δ ω ] v v P [ P ω ] µ δ µ u [ ω ] Figur 4: Goba conro o h SMI sysm wih SC v µ δ µ u usc 5h PSCC, ig, -6 Augus 5 Sssion, Papr, Pag 4

5 4 SIMUAION RSUS o vaua h abov goba conro schms or ransin sabiiy nhancmn an voag rguaion, h xamp SMI sysm in Figur is uiiz in h simuaion suy. Sinc h goba conro o gnraor xciaion or ransin sabiiy an voag rguaion has bn abora in [], w ony prsn h simuaion rsus raiv wih h goba conro o SC an h goba conro o h SMI sysm wih SC in his papr. 4. Paramrs in SMI sysm wih SC h sysm paramrs an physica imis o gnraor an inar xciaion sysm ar givn as oow: Synchronous machin: ω = ra/sc.; D = 5. p.u.; H = 4. sc.; = 6.9 sc.; =.3 p.u.; =.6 sc.; q k = ; c =.863 p.u.; = 57 p.u.; =.7 p.u.; a = 5 p.u.; = 57 p.u.; q =.7 p.u.; h q physica imis o h xciaion voag is max kcu = 6. p.u. ransmission ins: = 6 p.u.; R =.3 p.u. = 5Hz ; =.7 p.u; s = p.u. h paramrs an physica imis o SC ar as oow:. R. sc.; =. p.u.; =. p.u.; C k = ;.. p.u. h opraing poin o h sysm consir in h simuaion isδ = 7., P =. p.u.; =.5 p.u. A symmrica hr-phas shor circui au occurs a h rmina o gnraor bus. wo au squncs in h simuaion ar scrib as oow: Cas. mporary Fau: - Sag : h sysm is in a pr-au say sa. - Sag : A au occurs a =. scon. - Sag 3: h au is rmov by opning h brakr o h au in a. scon. - Sag 4: h ransmission in is rsor wih h au car a =.4 scon. - Sag 5: h sysm is in a pos-au sa. Cas. Prmann Fau: - Sag : h sysm is in a pr-au say sa. - Sag : A au occurs a =. scon. - Sag 3: h au is rmov by opning h brakrs o h au ins a =. sc. - Sag 4: h sysm is in h pos-au sa. Using h sysm paramrs sa abov, our paria conrors can b obain. h ransin conror o gnraor xciaion: v ( ) = δ +5 ω P h voag conror o gnraor xciaion: v ( ) v = ( ) ω -.96 P h SC ransin conror: u ( ) = ω ( ) h SC voag conror: v = h consan α an α ar chosn an.5 rspcivy in h simuaion. 4. Goba conro o SC In orr o monsra h civnss o h goba conro o h SC cary, h convniona inar xciaion conror is us wih h goba conror o SC. h paramrs o inar xciaion conror can b oun in Appnix. Powr ang (gr) h voag oupu o gnraor (p.u.) ransin conror oag conror Goba conror oag conror ransin conror Goba conror Figur 5: Rsponss wih irn SC conrors (Cas ) Powr ang (gr) h voag oupu o gnraor (p.u.) mporary au Prmann au mporary au Prmann au Figur 6: Rsponss wih goba SC conror (Cass an Cas ) h powr sysm rsponss wih irn SC conror subjc o irn aus ar shown in Figur 5 an 6. I can b obsrv ha goba SC conror can achiv saisi prormanc compar wih h 5h PSCC, ig, -6 Augus 5 Sssion, Papr, Pag 5

6 conrors sign or sing objciv. h goba SC conror can hp rsor h say pr-au voag vau an amp h osciaion whn h sysm is subjc o h mporary or prmanny aus. 4.3 Goba conro o h SMI wih SC Powr ang (gr) xciaion + SC Gnraor xciaion In his subscion, h prormancs o goba conro schm shown in Figur 3 ar iusra in Figur 7 an 8. Figur 7 xhibis goo ransin prormanc an rsoraion voag o goba conro schm compar wih h sysm wih ony goba conro o gnraor xciaion. h powr sysm rsponss shown in Figur 8 monsra ha h goba conro objcivs can b raiz in h prsnc o irn au cass by h propos goba conro schm. hus, h ra-o probms can b succssuy sov by his conro schm. h voag oupu o gnraor (p.u.) h sp o gnraor (ra/sc.) h voag o SC bus(p.u.) h xciaion inpu(p.u.) xciaion + SC Gnraor xciaion xciaion + SC Gnraor xciaion xciaion + SC Gnraor xciaion xciaion + SC Gnraor xciaion (c) () () Figur 7: Rsponss wih goba conro schm (Cas ) Powr ang (gr) h voag oupu o gnraor (p.u.) mporary au Prmann au mporary au Prmann au Figur 8: Rsponss wih irn au cass. 5 CONCUSION In his papr, h goba conro is xn o uncrain powr sysms o mainain h ransin sabiiy an achiv propr pos-au voag. h powr sysm is irs compos ino svra paria mos accoring o irn conro objcivs, opraing sags, conror inracions an goba conro objcivs. hn h DF chniqu is appi o inariz h paria noninar mos an robus paria conrors ar sign o consir h sysm uncrainis an conror inracions or irn paria mos. Ony oca variabs ar n in h sign o paria conrors. Finay, h goba conro aw is obain by aggrgaing h paria conrors wih mmbrship uncions. h SMI powr sysm wih h SC a h mipoin o h ransmission in is uiiz as an xamp sysm o vaua h civnss o h propos goba conro approach. oh h SC goba conro an h goba conro schm or gnraor xciaion an SC hav achiv goo ransin prormanc an rsor h say pr-au voag vau. hror, h propos goba conro schm can succssuy sov h ra-o probms in h pracic. his goba conro schm is xpc o xn o h mui- 5h PSCC, ig, -6 Augus 5 Sssion, Papr, Pag 6

7 machin sysms by combin wih h cnraiz conro chniqus. RFRNCS [] O. Akhri., A.F. Okou,.A. Dssain an R. Champagn, Appicaion o a muivariab back inarizaion Schm or roor ang sabiiy an voag rguaion o powr sysms, I rans. on Powr Sysms, o. 4, No., pp. 6-68, May 999. [] Y. Guo, D. J. Hi an Y. Wang, Goba ransin sabiiy an voag rguaion or powr sysm, I rans. on Powr Sysms, o. 4, pp ,. [3] Y. Wang, H. Chn, R. Zhou an D. J. Hi, Suis o voag sabiiy via a noninar SC conro, I Powr nginring Sociy Winr Ming,, o., pp ,. [4] Y. Wang, Y.. an, an G Guo, Robus noninar coorina xciaion an SC conro or powr sysms, Proc. o h 4h In. Con. on Avancs in Powr Sysm Conro, opraion an Managmn, APSCOM-97, pp [5] I. Kamwa, R. Gronin an Y. Hbr, Wi-ara masurmn bas sabiizing conro o arg powr sysms-a cnraiz/hirarchica approach, I rans. on Powr Sysms, o. 6, No., pp 36 53,. [6] P. Kunur. Powr Sysm Sabiiy an Conro. McGraw-Hi, 996. [7] K.. aw, D.J. Hi an N.R. Gory, Robus conror srucur or coorina powr sysm voag rguaor an sabiizr sign, I rans. on Conro Sysms chnoogy, o., No. 3, pp 3, 994. [8] H.F. Wang, Inracion anaysis an co-orinaion o SC voag an amping conro, Proc. O In. Con. on DRP (cric Uiiy Drguaion an Rsrucuring an Powr chnoogis), o. 4-7 pp ,. [9] D. J. Hi, Y. Guo, M. arsson, an Y. Wang, Goba conro o compx powr sysms, in iurcaion Conro: hory an Appicaions, G. Chn, D. J. Hi an. Yu (.), cur Nos in Conro an Inormaion Scincs, Springr-rag, Aug. 3. []S.A. Shahrsani an D. J. Hi, Goba conro o srss powr sysms, Proc. 39h I Con. Dcision an Conro,, o. 4, pp38-385,. []J. ung, D. J. Hi, Y.. Ni an R. Hui, Goba Powr Sysm Conro wih a Unii Powr Fow Conror, PSCC, Jun 4-8,, Svi, Spain; []Y. Wang, G. H. Zhang an D. J. Hi, Robus powr sysm ransin sabiiy nhancmn: a goba conro approach, h 6h IFAC symposium on Noninar Conro Sysms, Sp. 4, Sugar, Grmany. [3]D. J. Hi, G. H. Zhang an Y. Wang, Goba robus conro o uncrain sysms an is appicaion o powr sysms, h 3r Chins Conro Conrnc, Aug. 4, Wuxi, China. [4]C. Zhu, R. Zhou an Y. Wang, A nw noninar voag conror or powr sysms, In. J. crica Powr & nrgy Sysms, o. 9, pp9-7, 997. APPNDI A. Noaion or h SMI sysm wih SC δ : h powr ang h gnraor; ω : roor sp o h gnraor; ω : synchronous machin sp; P ( ) : h aciv crica powr ivr by h gnraor; P : h mchanica inpu powr o h m gnraor; Q ( ) : h raciv powr o h gnraor; D : h amping consan o h gnraor; H : h inria consan o h gnraor; : h irc axis o ransin opn circui im consan; u ( ) : h inpu o h SCR ampiir o h gnraor; k : h gain o h c xciaion ampiir o h gnraor; I ( ) : h xciaion currn o h gnraor; : inini bus voag; s : irc axis racanc o h gnraor; : irc axis ransin racanc o h gnraor; a : muua racanc bwn h xciaion coi an h saor coi; : racanc o h ransmission in; R : rsisanc o h ransmission in; : racanc o h ransormr; :h hvnin s quivan racanc o h nwork o h righ o gnraor rmina bus as shown in Fig. ; = + + ; = + + ; ( ) : suscpanc o h CR o h SC; : im R consan o h conro sysm o h CR o h SC; k : gain o h conro sysm o h CR o h SC; u : inpu o h conro sysm o h CR o h SC.. Paramrs o h inar xciaion conror AR: I SAxciaion sysm, K = 6; A = A.5sc.; K =.5; =.sc.; I = 4.4 p.u.; R K = 4.54 p.u.; R < 999. p.u.; < 6. p.u. A PSS: h ransr uncion o PSS can b rprsn as: rs ( + s ) GPSS = KPSS + rs ( + s) whr K =5; PSS =3 sc.; r =.5 sc.; =.5sc.; <.5 p.u. PSS 5h PSCC, ig, -6 Augus 5 Sssion, Papr, Pag 7