Amern Journ of Apped Senes 5 (11): 144-148, 008 ISSN 1546-939 008 Sene Pubtons Performne Comprson of Three-Phse Shunt Ate Power Fter Agorthms 1 Moeykutty George nd Krtk Prd Bsu 1 Futy of Engneerng nd Tehnoogy, Mutmed Unersty,75450 Mek, Mys Futy of Engneerng, Mutmed Unersty, 63100 Cyberjy, Mys Abstrt: The uge of pre onerters s eer nresng. Howeer, the otge nd urrent hrmons, zero-sequene nd negte- sequene omponents of otge nd urrent nd rete power present n pre onerters ge n rmng sgn to power system nd power eetron engneers. Ths reserh dsusses performne of three-phse shunt te power fter (APF) system usng three dfferent ontro tehnques nmey synhronous deteton gorthm (SDM), nstntneous te nd rete (p-q) theory nd nstntneous dret nd qudrture (d-q) urrent for the ontro of zero nd negte sequene omponents, rete power nd hrmons. The noety of ths reserh es n the suessfu ppton of SDM bsed APF nd (d-q) urrent APF for the ontro of rete power, hrmons nd negte nd zero sequene urrents resuted by the use of pre three-phse onerters. MATLAB 6.1 toobox s used to mode the systems. Key words: pre onerters, zero-sequene, negte sequene, SDM, p-q theory, d-q INTRODUCTION The uge of pre onerters s nresng due to hgh rebty, hgh power, dstrbuted power, hgh performne nd enbng tehnoogy for emergng pptons [1]. Howeer the presene of zero-sequene nd negte- sequene omponents of otge nd urrent hrmons nd rete power present n pre onerters ntrodues mny derse effets. The presene of negte-sequene nd/ zero-sequene omponents ntrodues symmetry nd s n ndton of bnorm ondton n whh these omponents re found. APF systems he been suessfuy ntrodued for the ontro of zero-sequene nd negte-sequene omponents n unbned systems [-4] nd ontro of zero-sequene omponents n pre onerters [5]. A deted dsusson on modeng of pre onerters nd ontro of rutng zero-sequene urrents nd rete power ruton hs been dsussed n [1]. Ths reserh dsusses the performnes of APF systems usng SDM, p-q theory nd (d-q) urrent for the ontro of zero nd negte sequene omponents of urrent, rete power nd urrent hrmons. The noety of ths reserh es n the suessfu ppton of SDM bsed APF nd (d-q) urrent APF for the ontro of rete power, hrmons nd negte nd zero sequene urrents resuted by the use of pre three-phse onerters. The ontro strteges of APF system re deted n the seond prt of ths reserh. Smuton resuts n the thrd prt demonstrte the effeteness of SDM nd (dq)urrent for the ontro of APF system to hee bned urrent snusods n phse wth the suppy otges. CONTROL OF APF SYSTEM Prnpe of operton: Bsy n APF system [6] s used for urrent ompenton. The ompenton urrents re generted by propery ontrong the otge soure nerter (VSI) n the urrent ontro mode. It hs been obsered tht for the suessfu operton of APF system the ptor otge of the nerter system shoud be 1.5 tmes the mxmum neto-ne otge [6]. A booster ndutor oud be used to onert the VSI n the urrent ontro mode. In ths reserh VSI s ssumed to be nstntneous nd nfntey fst to trk the ompenton urrents, hene t s modeed s urrent mpfer wth unty gn nd the smunk mode of the nerter sub system used s shown n Fg. 1 [7]. Three dfferent ontro gorthms nmey SDM, p-q theory nd d-q urrent re dsussed to generte the ompenton urrents. Correspondng Author: Moeykutty George, Futy of Engneerng nd Tehnoogy, Mek Cmpus, Mutmed Unersty, 75450, Mek, Mys Te: +606 5386 Fx: +606-31 655 144
nd the unt mptude we form n synhronsm wth the suppy otge s gen by: V sm (6) Thus the referene soure urrent: P (7) Vsm Fg. 1: Inerter sub-system Smry Contro of APF system usng SDM: In ths gorthm, the three-phse soure urrents re ssumed to be bned fter ompenton. The re power p onsumed by the od oud be uted from the nstntneous otges nd od urrents s: P sb b sb (7b) Vsmb P s s (7) Vsm p [ sb s ] b (1) where, V sm, V smb, C sm re the mptudes of the suppy otges. The ompenton urrents re then uted usng Eq. 8-8: where,, sb, s re the nstntneous ues of suppy otges nd, b, re the nstntneous ues of od urrents. The erge ue P d s determned by ppyng p to ow pss fter. The re power s then spt nto the three phses s foows: (8) b sb b (8b) s (8) Vsm P Vsmb Pb Vsm P () (b) () Thus for purey snusod bned suppy otges: where, P V I P P P P 3 d b (3) V I V I sm sm sm sm (4) P Ism (5) Vsm 145 Contro of APF system usng p-q theory: The p-q theory proposed by Akg [8] to determne the ompenton urrent to be njeted by the APF system for hrmon emnton nd rete power uses Prk s trnsformton from three-phses (, b, ) to two phses ( nd β). The three phse suppy otges nd od urrents oud be trnsformed nto the -β. orthogon oordntes s foows: 1 1 1 s sb sβ 3 0 3 3 s 1 1 1 b β 3 0 3 3 (9) (10) Aordng to p-q theory, determnton of nstntneous re power p nd mgnry power q s gen by the expresson:
p s sβ q sβ s β (11) where, p nd q ontn d nd terms nd n be wrtten s: p p + p (1) q q + q (13) To hee unty power ftor nd hrmon emnton, the term p nd the mgnry power q he to be emnted. The ompenton power p oud be obtned by fterng out the omponents from p. Thus: nd p p (14) q q (15) The referene ompenton urrent n -β pne s gen by the expresson: 1 s sβ p sβ β s q the (16) osθ snθ sd sb os( θ 10 ) sn( θ 10 ) sq s os( θ 40 ) sn( θ 40 ) (17) And the ompenton urrents re then uted usng the me Eq. 8-8 used n SDM. RESULTS AND DISCUSSION APF systems bsed on SDM, p-q theory, d-q theory hs been suessfuy modeed nd tested usng MATLAB 6.1 toobox for the ontro of zero sequene nd negte sequene omponents, hrmon omponents nd rete power resuted by the use of pre three-phse onerters. The effeteness of the system hs been suessfuy tested for dfferent frng nges wth two pre onerters. The performne of the deeoped systems s ustrted for 1 0 nd 90 s shown n Fg. 3-13. One my note tht unbned pre onerters ntrodue rete power, hrmons, negte nd zero sequene omponents of fundment nd hrmon omponents. It hs been obsered tht APF bsed on p-q theory fs to ompetey emnte negte nd zero sequene omponents. The performne of the system usng d-q urrent s omprbe wth tht of SDM nd SDM shows supremy n heng three bned urrent snusods n phse wth the suppy otges. V d nd the referene ompenton urrents for phse, phse b nd phse oud be euted usng Prk s bkwrd trnsformton nd gen n mtrx form s foows: 1 0 sq 0 b 1 1 3 3 (17) β 1 3 Fg. : Contro rut of APF system d-q usng urrent Contro of APF system usng d-q urrent : Fgure shows the bok dgrm of ontro rut of n APF system usng d-q urrent. In ths poste sequene omponent of the frst hrmon omponent of od urrent hs been treted s the d-xs omponent of the referene soure urrent, where s the q-xs omponent of referene soure urrent s zero n n de bned three-phse system. Now the referene soure urrents n the, b, pne Tme (se) oud be obtned by the use of Prk s trnsformton from sttonry xes d, q to, b, frme s foows: Fg. 3: Pots of soure otges nd soure urrents 146 1 Poste sequene extrton of fundment omponent Votge ontro + sd V dr d-q to -b- trnsformton s - +
Pots of s nd s(a) Tme (se) Fg. 4: Pots of Soure otges nd soure urrents usng p-q theory Tme (se) Fg. 8: THD s of od nd soure urrents usng d-q Tme (se) Fg. 5: Pots of Soure otges nd soure urrents usng p-q Tme (se) Fg. 9: THD s of od nd soure urrents usng SDM Pots of s nd s(a) Tme (se) Fg. 6: Pots Soure otges nd soure urrents usng SDM Tme (se) Fg. 10: Pot of zero-sequene urrent usng p-q theory Tme (se) Tme (se) Fg. 7: THD s of od nd soure urrents usng p-q Fg. 11: Pot of zero-sequene urrent usng d-q theory 147
ACKNOWLEDGMENT The uthors re grtefu to An Tn Wee Cht, Dr. Abduzeez S. Boujrwh, Chrsto George, K. S. Suresh Kumr, Prof. K Rmr nd Dr. Surbh Kumr Mukerj for ube dsussons. REFERENCES Tme (se) Fg. 1: Pot of zero sequene urrent usng SDM Tme (se) Fg. 13: Cptor otge obtned usng CONCLUSION APF systems bsed on SDM, p-q theory, d-q urrent he been suessfuy deeoped usng MATLAB 6.1 toobox. The noety of ths reserh es n the suessfu ppton of SDM bsed APF nd d- q urrent APF for the ontro of rete power, hrmons nd negte nd zero sequene urrents resuted by the use of pre three-phse onerters. It hs been obsered tht APF system bsed on p-q theory fs to hee the desred trget. 1. Zhong, Y., 000. Modeng nd Contro of Pre Three-Phse PWM Conerters: Theses Report, Vrgn Poytehn Insttute nd Stte Unersty, http://shor.b.t.edu/.. Bhrju, V.B. nd P.N. Enjet, 1993. Anyss nd desgn of n te power fter for bnng unbned ods: IEEE Trns. Power Eetron., 8 (4): 640-647. 3. Bhrju, V.B. nd P.N. Enjet, 1996. An te ne ondtoner to bne otges n threephse system: IEEE Trns. Ind. App., 3 (): 87-9. 4. Enjet, P.N., W. Shreen, P. Pkebush nd I.J. Pte, 1994. Anyss nd desgn of new te power fter to ne neutr urrent hrmons n three-phse four-wre eetr dstrbuton systems. IEEE Trns. Ind. App., 30 (6): 1565-157. 5. George, M. nd C.L. Seen, 004. Modeng nd ontro of zero-sequene urrent of pre threephse onerters usng Mtb/power system bokset. IEEE Power Systems Conf. nd Exp. 004, 3: 1440-1443. 6. Moeykutty George, 004. Modeng nd smuton of urrent ontroed three-phse shunt te power fter usng MATLAB/PSB. AIUB. J. S. Eng., 3 (1): 11-18. 7. Suresh Kumr K. S., 004, Three-phse shunt te power fters, prt III-Smuton of ontro systems: Seeted tops n power quty nd ustom power, pp.3. 8. Akg, H., 1994. Trends n te power ne ondtoners. IEEE Trn. Power Eetron., 9 (3): 63-68. 148