SSSC circuit model for three-wire systems coupled with Delta-connected transformer

Transcription

1 SSSC rut moe for three-wre ytem oupe wth Det-onnete trnformer G. oh Srv Futy of Eetr Engneerng K. N. Too Unverty of Tehnoogy Tehrn, Irn Dr M. Tvko n Futy of Eetr Engneerng K. N. Too Unverty of Tehnoogy Tehrn, Irn tvko@kntu..r trt Th pper preent new rut moe of SSSC e on tte equton n three-wre ytem. SSSC ere ompentor of FCTS fmy. It njet n mot nuo votge wth vre mptue n equvent to n nutve or ptve retne n ere wth the trnmon ne. The ny of power eetron ytem ompex, owng to t wthng ehvor. Sne uh ytem h t pe ompexte, the nee for mper moe eent, though more prt one ometme pproprte. Wth mpe hnge, th pper moe how fferent tte of SSSC, oth trnent n tey tte, n the rnge of e to prt onfrme y MTL muton. Th moe ute for rut muton oftwre uh MTL or PSPICE n proper to ontro proe n ontro metho. Th moe n e ue trtng pont for further nvetgton on ontro metho n the future. Keywor: SSSC moe, SSSC Crut Moe, tte equton, SSSC trnent. I. INTRODUCTION The rp eveopment of power eetron tehnoogy prove extng opportunte to eveop new power ytem equpment for etter utzton of extng ytem. Durng the t ee numer of ontro eve uner the term Fexe C Trnmon Sytem (FCTS tehnoogy hve een propoe n mpemente. The FCTS eve n e ue for power fow ontro, oop fow ontro, o hrng mong pre orror, votge reguton, n enhnement of trnent tty n mtgton of ytem oton. FCTS hve eome n eent n ntegr prt of moern power ytem. Moeng n gt muton py n mportnt roe n the ny, egn, tetng n ommonng of uh ontroer. Stt Synhronou Sere Compentor (SSSC ere ompentor of FCTS fmy. It njet n mot nuo votge wth vre mptue. It equvent to n nutve or ptve retne n ere wth the trnmon ne. The hert of SSSC SI (votge oure nverter tht uppe y DC torge ptor []. Wth no extern DC nk, the njete votge h two prt: the mn prt n qurture wth the ne urrent n emute n nutve or ptve retne n ere wth the trnmon ne, n m prt of the njete votge n phe wth the ne urrent to over the oe of the nverter []. When the njete votge eng the ne urrent, t w emute ptve retne n ere wth the ne, ung the ne urrent we power fow through the ne to nree. When the njete votge ggng the ne urrent, t w emute n nutve retne n ere wth the ne, ung the ne urrent we power fow through the ne to eree [3]. SSSC uperor to other FCTS equpment n the eneft of ung SSSC re te n [4]. Pper [5] n [6] hve egne the power fow ontroer of SSSC e on NN metho n Fuzzy ef-tunng PID nvuy, n the reut how they mprove the ef-ptng n the routne, n eerte the pee of power fow jutment. Pper [7] h ut SMI ytem wth SSSC n TCSC y ung the SIMPOWERSYSTEM tooox of MTL, n then the trnent hrtert mute. The effet of mpng power oton h een ompre etween fferent wth moe of SSSC. ee, the wth trtegy of ntern fut n extern fut ummrze. Thee pper fou on the moeng n ontrong SSSC n propoe mny moe ute for power fow n other ppton. mot of them hve ue the phor equton for uton n extrtng the moe whh ee other ppton ppe for the ontro n SSSC ontroer. Phor equton e on tey tte onon expn ytem ehvor t tey tte ut n not how the ytem ehvor t trnent tte. To ontro ytem, t pree ehvor neee n trnent n tey tte, n fut onon. Therefore, the new moe of SSSC neee to how the trnent ehvor n to hve enough et out SSSC. On the other hn, the moe hou hve the ty to e mpfe for other ppton uh power fow or tey tte onon n n vry etween ompte n mpfe moe wth nomn hnge n t. The tme equton expoun the trnent n tey tte n fut onon n ehvor of ytem. If we n get the SSSC rut moe from tme equton, th moe n expoun ehvor of SSSC t trnent n tey tte n other onon. In th pper, frt, the tte equton of SSSC, Thévenn Equvent Crut of network n the wthng funton re expne. e on thee equton, the SSSC moe n t mpe PI ontro re propoe. The next prt emontrte the //$5. IEEE

2 MTL muton reut. The SIMPOWERSYSTEM tooox (eron 4.3 (R6 of munk ue for muton. II. SSSC STTE SPCE EQUTIONS ND THÉENIN EQUILENT CIRCUIT OF NETWORK ume tht the onverter votge yntheze ung PWM or SM ontro, n the ontro oop foue on α. The open-oop equton re otne n tnr form tht n ter e mofe for oe-oop ontro: x f ( x( ( u( ( Where x(t the tte vetor: T x(t [ ( ( (t] ( u(t the nput vetor: [ ( ( ( t ] T u r r r (3 n (t the vetor of wthng funton. [ ( ( ( t ] T (4 The tte pe moe of ( nue rete wthng funton ong wth the mn votge-uppe oure. Coner the SSSC hown n Fg. There re two topoog moe for every eg. The tte equton for the two moe n e otne eprtey n then, ntroung the wthng funton {, }, efne the output votge of onverter n wth wthng funton eow: C (5 (6 Fg how the three-phe rut of SSSC, network n onneton etween them. otge oure ( n r, retne (R n R n nutor (L n L n fgure re the thévenn equvent rut of network n trnmon ne. The trnformer onnet together wth et onneton n trnformer turn rto ume to one. ummry of the equton to get the fn equton for SSSC moe expne eow: C (7 ( R L x ( R L (8 R R L L R L (9 ( x ( R L r ( x x ( For other phe o the me phe. Thu, from (5 to ( n other phe equton we otn: R (3L L ( r (3 R (3L L ( r (4 Suttutng,, from (5 to (3 n (4 gve: R (3L L ( r R (3L ( r L ( (5 ( (6 From (6, (5 n (6 the tte equton re onue eow: (3L L 3R R ( 3L L C 3R R ( 3L L C r r ( (3L L ( (3L L (7 To get the rut moe of SSSC, frt efne two nepenent votge oure: f (( u( [ r ] (8 f (( u( [ r ] (9 ong wth two votge-ontroe votge oure (CS re efne foow: g ( ( ( ( g ( ( ( ( Three tte equton (5, (6 n (6 ere the nutor urrent n ptor votge. The frt two equton men tht the nutor urrent epen on the votge fferene etween the nepenent oure (8, (9 n epenent oure (, (. The thr equton (6 how tht

3 the urrent of ptor C ompoe of two urrent ontroe urrent oure (CCCS h n h, eh funton of wthng funton n ne urrent. ( ( ( ( (, ( ( t t t h t t ( ( ( ( ( (, ( ( t t t h t t (3 orng to ove equton we hve: (( 3R R (3L L g ( ( f ( u( (4 (( 3R R (3L L g ( ( f ( u( (5 C h ( ( ( h ( ( ( (6 The reutng equvent rut moe hown n Fg, n ute for rut mutor uh MTL or PSPICE. Note tht the ptor rut hou e onnete to the nutor rut ung two very g mpene Z for PSpe muton, whh eve negge effet on the rut ehvor. The hert of SSSC SI onverter whe the mportnt prt of SI t wthe n wthng metho. If hvng n e onverter, t n mke e nuo wve form wthout ny hrmon. The frther from e onverter, the rnge n mptue of hrmon nree. In prt moe, the rge rnge of hrmon onge the mn hrmon re me. Thee n e hown y wthng funton. If hrmon me n prt tuton re negete, (t, (t & (t n e uttute wth nuo wve form. If re muton neee n hrmon re tken nto ount, (t, (t & (t n e uttute wth re wve form of wthe how n Fg 3. (t, (t & (t nue the we rnge of funton, whh y exertng eh of them ehvor of SSSC v-à-v tuton ttne. For exmpe, f (t, (t & (t re uttute wth the prt wthng funton (the funton nue the pue me y PWM, SM (Fg 3 or other prt pue mker, the moe how the prt moe of SSSC. If (t, (t & (t re uttute wth the verge of prt wthng funton (expne n [8], the moe how the verge ehvor of SSSC n emnte ome hrmon epenng on vergng pero. If (t, (t & (t re uttute wth the e wthng funton, tht, n e onverter ext to mke the ext nuo wve t output of onverter, the moe how ehvor of SSSC n e onon y regr of hrmon n torton. Or f (t, (t & (t re uttute wth the fxe hrmon nuo wve, the moe how the ehvor of SSSC tht rete to th hrmon, o the effet of one hrmon on SSSC n e eorte. For exmpe, f (t, (t & (t re uttute wth mn hrmon pu the thr hrmon, the effet of thr hrmon on trnent tte n power of SSSC n e nyze. Therefore, th moe n how the SSSC ehvor n vrou onon. When mpe moe of SSSC neee, mpfe onon n mtton re ue, or ee, when ompete moe of SSSC neee, ompte onon n mtton re ue. III. SSSC CONTROLLER The f metho ppe for ontro of SSSC [8]. In th metho wth hnge of the f (f the nge of onverter output votge, n Fg the nge of pont n fnte rnge, the tve or ntve power (njete or reeve n the ere rnge n e ontroe. Th propoe moe n e ue trtng pont for ext uton of f n the next pper. Fgure. three-phe rut of SSSC, network n onneton etween them I. MTL SIMULTION RESULTS Th eton how muton reut for SSSC prt moe (Fg 4, 5 & 6, n SSSC e moe wth the 4th hrmon (the mptue of the 4th hrmon equ to 3 perent of mn hrmon me y onverter (Fg 7. For

4 prt moe the reut of three fferent onon re hown: SSSC work n ptve moe, SSSC work n nutve moe, n 3 trneny of SSSC, hngng from nutve moe to ptve moe. n for eh of them the ntve power of SSSC hown tht njete nto or reeve from network t trnformer termn, the ne urrent n ptor votge(. Fgure. equvent rut moe of SSSC, ute for rut mutor uh MTL The prmeter of network n SSSC ue for muton re: n(w n(wt-π/3, n(wtπ/3, r95n(wt-5π/8, r95n(wt- 5π/8-π/3, r95n(wt-5π/8π/3, RR.5Ω, LL.6mH, R.5Ω, L.mH, C.mF, (v, ωπ. In Fg 4 & 5, t the trt of muton, the SSSC nether njet ntve power nto the network nor reeve t from the network (nt onon. t the next tge, ontroer jut f nge o tht the SSSC njet 75 r nto the network t ptve moe n reeve 75 r from the network t nutve moe. In Fg 6 & 7, t the trt of muton, ontroer jut f nge o tht the SSSC reeve 75 r from the network t nutve moe (nt onon. t. eon, the ontroer hnge t trget n jut f nge o tht the SSSC njet 75 r nto the network t ptve moe. Thee reut how tht the ptor votge ten to nree for α.7 (ptve moe n eree for α37.48 (nutve moe ompre wth the ptor votge when the SSSC nether njet ntve power nto network nor reeve t from the network. Fg 7 how the effet of the 4th hrmon t SSSC n njetng nto or reevng ntve power from network. Th hrmon (4th one of the fmou hrmon proue n onverter urng the wthng. rou tte of SSSC y hep of hngng the nput wthng funton n e tue n th moe.. CONCLUSION Th pper propoe the new SSSC rut moe e on tme equton n three-wre ytem wth et onneton for ere trnformer. Th moe nue the wthng funton, n wth nomn hnge n thee funton, mute fferent tte of SSSC, tht, trnent n tey tte. Th moe ute for rut muton oftwre n ontro metho. Fgure 3. proue pue y -eve SM for nuo wve form, wthng pero khz To ute three-phe ntntneou power, the wy expne n [9] n efne n eow ue. For three-phe power ytem, ntntneou votge v, v, v n ntntneou urrent,, re expree ntntneou pe vetor, n, tht : v v, (7 v The ntntneou tve power of three-phe rut, p, n e gven y p where enote the ot (ntern prout, or r prout of vetor. Intntneou pe vetor q efne q where enote the ro (exteror prout of vetor or vetor prout. etor q egnte the ntntneou ntve power vetor of the three-phe rut, n the mgntue or the ength of q, q, egnte the ntntneou ntve power, tht, q q. Fgure 4. muton reut for prt moe of SSSC, opertng n ptve moe (α.7. Lne urrent n ptor votge. The ntve power of SSSC tht njete nto network

5 Fgure 5. muton reut for prt moe of SSSC, opertng n nutve moe (α Lne urrent n ptor votge. The ntve n tve power of SSSC tht reeve from network Fgure 7. muton reut for trnent tte of SSSC from nutve moe (α37.48 to ptve moe (α.7 y e SSSC wth 4th hrmon moe. Lne urrent n ptor votge. The ntve power of SSSC tht njete nto n reeve from network Fgure 6. muton reut for trnent tte of SSSC from nutve moe (α37.48 to ptve moe (α.7 y prt moe. Lne urrent n ptor votge. The ntve power of SSSC tht njete nto n reeve from network I. REFERENCES [] L.S.Kumr,.Ghoh, Moeng n ontro egn of tt ynhronou ere ompentor, IEEE Trn. on Power Devery, 999, 4(4, pp [] Yong Hu Song, n T John, Fexe trnmon ytem (FCTS Lonon: The Inttuton of Eetr Engneer, 999, pp [3] Kyn K. Sen SSSC- Stt Sere Compentor: Theory, Moeng n ppton IEEE Trn. on Power Devery, o.3, No. Jnury 998. [4] L. Gyugy, C. D.Shuer, Kyn K.Sen, Stt Synhronou Sere Compentor: o -tte pproh to the ere ompenton of trnmon ne. IEEE Trn on Power Devery, 997, (, pp: [5] YNG Q, WNG Hu. SSSC power fow ontro e on rtf funton neur network, Tehnoogy of Eetr Mhne n ppne, 5(5, pp.7-. [6] W. Hu, W. Yonn, X. Weong, Invetgton of Powe Fow Controer of SSSC e on Sef-Tunnng PI Controer wth Fuzzy Log, Trnton of Chn Eetrotehn Soety. 4, 9(7, pp [7] L. Qng, W. Zengpng, Z. Zhenhu, Stuy n Smuton of SSSC n TCSC Trnent Contro Performne, Power Sytem Tehnoogy n IEEE Power In Conferene,-5 Ot. 8, pp. 6. [8] M. Tvko n, D.C. Hm, verge rut moe for ngeontroe STTCOM, Eetr Power ppton, IEE Proeeng- oume 5, Iue 3, 6 My 5, pp: [9] F. Z. Peng, J-S. L, Generze ntntneou retve power theory for three-phe power ytem, IEEE Trnton on Intrumentton n Meurement, OL. 45, NO., FERURY 996, pp:9 95