analysis of svc and tcsc in voltage collapse

8/7/2019 analysis of svc and tcsc in voltage collapse

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ANALYSIS OF SVC AND TCSC

CONTOLLERS

IN VOLTAGE COLLAPSE

Submitted by:


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Two Flexib le AC Trans miss ion Sys tem ( FACTS) c on troll e rs, na me ly,

Sta tic Var Compe nsa tors (SVCs ) an d Thyris tor Con troll ed

Se ries Ca pa citors (TCSCs ), to s tudy t heir effect on vol tag e c olla ps e p heno me nain powe r s ys tem s.

Bas ed on re s u lts a t t he p o in t of colla ps e , de s ign s tra te g ies ar e p ropos ed f or

the s e t wo con trolle rs, so tha t t hei r loca tion, dime ns ions an d c on trols can beoptim all y defi ned t o increas e s ys tem loa da bility.

With the imp roveme n t in I an d V han d ling ca pa bilitie s of powe r e lect ron icde vice s tha t hav e allow ed f or de ve lopme n t of FACTS, the p oss ibility has ar is en of us ing diffe ren t type s of con trolle rs f or efficie n t sh un t an d s e ries compe nsa tion.

Thus FACTS c on trolle rs like SVCs an d TCSCs ar e bei ng us ed t o compe nsa tethei r s ys tem s.

Bette r mode ls an d new met ho dolog ies ar e p ro pos ed , e s peci all y f or the TCSC, with the a im of p roduci ng optim al imp roveme n ts in the loa da bility marg in. Fu r the rmor e , the effect of SVC an d TCSC s izing,L e .,compe nsa tionleve ls, in the loa ding marg in.

INTRODUCTION


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Voltag e c olla ps e s tudie s an d t hei r re la ted t ools ar e typic all y bas ed on the f ollow ing g ene ral ma them a tical de s cription of the s ys tem:

i = f(x, y, , p) - - - - - - - (1)0 = (x,y, ,p)

wh e re z R rep re s en ts the s ys tem s ta te var ia b le s, corr e s pon ding to dyna mic al s ta te s of g ene ra tors, loa ds, an d an y othe r time var ying e leme n t in the s ys tems uc h as FACTS c on trolle rs;

y R corr e s pon ds to the alg eb ra ic var ia ble s, us ually asso cia ted t o thetrans miss ion s ys tem an d s te a dy-s ta te e leme n t m ode ls, s uc h as so me g ene ra ting so u rce s an d loa ds in the net wor k;

A R s tan ds f or a s et of uncon troll ed p ara mete rs tha t d rive t he s ys temto colla ps e , wh ich ar e typic all y us ed t o rep re s en t t he so me wha t ran dom c hang e s in s ys temDem an d .

P R us ed he re t o rep re s en t s ys tem p ara mete rs tha t ar e di rect ly con trolla ble ,s uc h as sh un t an d s e ries compe nsa tion leve ls.

MODELING


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As the equi librium p o in t wh e re t he re la ted s ys tem j a cobian is s ing u lar i.e . the p o in t(x,y, ,p) wh e re

th is equi librium i s typic all y asso cia ted t o a sa dd le no de bifu rca tion po in t.


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The t wo mos t p opu lar con fig u ra tion of th is type of th is type of sh un t con trolle r ar ethe fixed c a pa citor (FC) with a thyris tor con troll e r ca pa citor (TCR) an dthe t hyris tor sw itched c a pa citor (TSC).

Of the s e t wo s etup s, the s ec on d (TSC) mi n imize s s tan d by loss e s.

con trol rang e of 90 t o 180 w.r. t c a pa citor vol tag e .valv e s a ut oma ticall y tu rn off a t ze ro cross ing of the a c cu rren t .


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The TCR a t fu nda me n tal f reque ncy with var ia ble induct an ce Xv

Wh e re Xl is the fu nda me n tal f reque ncy rea ctan ce is firing angl e of the valv e

Total equi val en t imped an ce Xe i s rep re s en ted by

Whr e rx= Xc/Xl


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The s te a dy s ta te c on trol law SVCIs rep re s en ted by f ollow ing vi chr.Eqn :

TCSC: the s te a dy s ta te s tructu re is of con troll e r fc- tc r sv cEqui val en t imped an ce TCSC a t 60 hz .


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SVC: re sonan t is no t a problemConn ected t o s ys tem i n sh un tAt re sonan t p o in t it sw itch off s ys tem

firing angl e 90 < < 180

TCSCs e ries conn ected

Re sonan t pt . Avo ided t o preven thar mon ic .Avo id cu rren t in te rrupti onsfiring angl e r<


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Depict s the equi val en t s us cept an ceBe= - 1/Xe vsBe var ies s moo thly w.r. t


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Ste a dy St a te eq . an d Limit1 .SVC

s te a dy s ta te be hav ior of the sv cIs g iven by


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It depict s the han d ling of SVC limit s


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2 . TCSC:Ste a dy s ta te ckt di a.

Conn ected bt . Bus e s k an d m

Con troll e r mode l is lossl e ss i.e . Active p owe r p a t no dek =p owe r a t m


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Con trol mode i s defi ne by on e of the f ollow ing eq . depe nding up on type of con trol chos en

Ma ximum TCS s e ries voltag e di rect ly a pp lied t o diffe ren t var ia ble s

Fla t s tar t in itial iza tion bas ed on* de s ign cons tan t,

* equi val en t rea ct an ce c hara cte ris tics * firing angl e s limit s

in itial firing angl e so chos en tha t no t c los e t o re sonan t p o in t an d p rov ide widerang e of loa ding con dition .


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Eg of EUROPE AN SYSTEM in wh ich mode l an d tec hn ique s ar e u s ed

The s ys tem has 560 bu s e s , 1 2 9 g ene ra tor

bu s e s , 7 23 line s in trans f or me rs

And 14 ar eas

Pow e rs s upp ly f rom N TO S.Gene ra tor ar e m ode ledas s tan dar d PV bus e s with Bo th P an d Q limit s

LTCs ar e kept fixed a t in itial Pos ition

Pl an d Ql rep re s en t in itial loa ding con d .

For ar ea 1 an d ar ea 2 :Kp=Kq= 2 .5


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Effect of chang ing SVC compe nsa tion leve ls a t c ritical bu s 41 3 in (a ) Loa ding marg in

(b) Pe rf or man ce me as u re Fp


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Effect of chang ing TCSC compe nsa tion leve ls f or critical line 409- 4 3 6 i n (a ) loa ding marg in (b) pe rf or man ce me as u re Fp


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CONCLUSION Adequ a te m ode ls an d re la ted equ a tions f or rep re s en ting SVCs an d TSCs in s te a dy

Sta te s tudy , par ticu larl y voltag e c olla ps e ar e p re s en ted .

Bas ed on vol tag e c olla ps e t heor y tec hn ique s f or optic all y loca ting an d dime ns ion ing The s e c on trolle rs ar e p ropos ed an d i llus tra ted i n a real s ys tem .

SVCs an d TCSC can be u s ed t o increas e s ys tem loa da bility in pra ctic al a pp lica tions .

FACTS c on trolle r hav e a dditi onal a dvan tag e of bei ng to con trol f as t s ys tem os cilla tion due t o the re quick re s pons e ; fu r the r mor e m a in ta inan ce c os t ar e lowe r as the re ar eno mec han ical sw itche s to worr y a bout t he s e c on trolle rs .


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THANK YOU

analysis of svc and tcsc in voltage collapse

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