LOAD BALANCING AND POWER FACTOR CORRECTION FOR MULTIPHASE POWER SYSTEMS

Transcription

1 nterntonl Journl of Ane Reserh n Engneerng n Tehnology (JARET) olue 7, ssue, Mrh-Aprl 6, pp. 9, Artle D: JARET_7 9 Alle onlne t Journl pt Ftor (6): (Clulte y GS) SSN Prnt: n SSN Onlne: AEME Pulton LOAD BALANCNG AND POWER FACTOR CORRECTON FOR MULTPHASE POWER SYSTEMS. K. Trpth Deprtent of Eletrl Engneerng SHATS, Allh, Uttr Presh Prof. (Col.) G. Sngh CSED SHATS, Allh, Uttr Presh ABSTRACT n reent yers the re of ult-phse (phse orer ore thn three) hnes s populr. A ult-phse soure y e ere fro trnsforer onneton (- phse to 4-phse) or y DC lnk 4-phse nerters. There re prole of unlne, hron storton n poor power ftor operton. Ths pper proposes the supply se lo lnng n power ftor orreton.the propose openston shee uses the shunt urrent soure openston whose nstntneous lues re eterne y the nstntneous syetrl oponent theory. An el openstor n ple of physl relzton of the openstor hs een propose n for of urrent ontrolle oltge soure nerter. The openston shees eelope n the pper re teste for ther lty on 4-phse (4-wre & 5- wre) ruts through extense sultons. nex Ters: Mult-Phse, Power Ftor Correton, Copenstor, Lo Blnng Cte ths Artle:. K. Trpth n Prof. (Col.) G.Sngh. Lo Blnng n Power Ftor Correton for Multphse Power Systes. nterntonl Journl of Ane Reserh n Engneerng n Tehnology, 7(), 6, pp etor@ee.o

2 . K. Trpth n Prof. (Col.) G.Sngh. NTRODUCTON Mult-phse Power systes he seerl nherent enefts suh s reue torque pulston, hron ontent n urrent per phse wthout nresng the oltge per phse, hgher systes hgher rellty n nrese power n the se fre s opre to ther three-phse ounterprt. So Mult-phse nerter fe nuton otor res (espelly 4-phse) re sutle for hgh power rtngs n other spelze ppltons. Howeer the use of suh ult res n ees y e effete y phse outges & unlne s well s nonlner long. Suh ontons y le to ny unesrle effets on the supply syste suh s tonl losses n onnetng lnes n nterfng ees, oslltory torques n hnes, nrese rpple n retfers, lfuntonng n senste equpents, hron n exesse neutrl urrents et. t s therefore esre to he the lne power syste operton wth nu lower orer hrons. A nuer of ethos he een eole for the openston of hrons n unlnes for the onentonl three phse systes. Generlly These ethos re se on the nstntneous rete power theory, theory of syetrl oponents, n referene fre theory Utlzng these theoretl onepts, tehnques he een eelope for lo lnng n power ftor orreton.ths pper resses the prole of lnng of n unlne 4-phse (Multphse) lo n power ftor orreton on supply se. The propose openston ethos he een erfe y sulton stues.. COMPENSATON SYSTEM t s ssue tht n el oltge soure s onnete to n rtrry lo Z L, rwng unlne urrent fro the soure. n Orer to ke the soure urrents lne, n externl ontrolle urrent soure lle openstor s propose to e onnete to the lo s shown n Fg..The pont of onneton of openstor to power syste s lle pont of oon onneton (PCC). The propose openston shee n e pple to oth four-phse four-wre n four-phse fe-wre power syste. n four-phse four-wre str onnete lo, the oon pont of the lo n s solte fro N, the oon pont of soure. On the other hn, n four-phse fe-wre syste, the neutrl pont s fore y onnetng the noes n n N n s lso onnete to the openstor t ts oon pont n s shown n fg().ths hs the ntge tht the openstor urrents,, & re urrents n nepenent ruts, n eh phse of the openstor n supply urrents nepenent of the other three phses. Fgure Copenston shee for 4-phse str onnete lo. 9 etor@ee.o

3 Lo Blnng n Power Ftor Correton for Multphse Power Systes. NSTANTANEOUS SYMMETRCAL COMPONENTS THEORY Followng the unlne four phsors of four-phse syste n e resole nto the four oponent systes of lne phsors known s: The zero sequene syste (zero phse fferenes); Frst- (poste) sequene syste (four phsors re sple 9 eg. relte to eh other). The seon-sequene syste (two phsors re sple 8 eg. relte to eh other, eh representng two phses, onsttutng two -phse zero sequenes n opposton); Thr-(negte) sequene systes (sequene n the opposte sense of rotton to tht of the frst sequene syste) The poste sequene oponents of lne four phse urrents l,,, he orgnl phse sequene lke the orgnl unlne four-phse urrents. These other three sets of oponents re shown n Fg..elow. o o o o () Zero sequene syste () Frst (poste sequene)syste () Seon sequene syste 9 etor@ee.o

4 . K. Trpth n Prof. (Col.) G.Sngh 94 etor@ee.o () Thr (Negte sequene) syste Fg. Syetrl Coponents of Four-Phse Syste As the orgnl unlne four-phse phsors re resole nto four oponents, the oponents when they re e yel the orgnl phsors. Therefore () A. Four phse opertor Now let the four phse oplex opertor e efne s,. exp / j j Fgure phsor gr n the rous power of opertor. Soe of the propertes of opertor '' re surze n equton. () J J J ()

5 Lo Blnng n Power Ftor Correton for Multphse Power Systes 95 etor@ee.o B. Trnsforton The syetrl oponents of four phse syste y e represente n trx for y equton. () () The nerse reltonshp of equton () y e wrtten s 4 (4) Wth the onentonl rotton of urrent etors n ounter lokwse reton, the nstntneous lue of the urrents n e expresse s follows. (5) The etors n re oplex onjugte to eh other n s rel quntty. The neutrl urrent - n wll e non zero f nstntneous urrent phsors re unlne n s lso equl to 4. The nstntneous syetrl oponent of n,, phse oltge n e wrtten n ter of,,, s followng equton (6) 4 (6) 4. CALCULATON OF COMPENSATOR CURRENTS The Copenstor urrent s lulte on the ss of nstntneous syetrl oponent nlyss of the lo urrent. An explt relton for the referene urrent s ere n ths seton y pplyng ult-phse nstntneous power syetrl oponent trnsforton. A openste soure wll he lne supply urrents n therefore ts zero sequene oponents wll e zero. Tht s, s s s (7)

6 . K. Trpth n Prof. (Col.) G.Sngh The lne phse urrents t esre power ftor ngle n e trnslte wth the help of (5) n (6) nto nother equton (8) s s s s s The nstntneous power n 4-phse 5-wre syste s gen y- s s s s s s s p (9) J lg Solng (8), y tkng e We otn - ( A B) Where, A s J, B s J tkng tngent on oth ses of () the followng relton s otne. s s () s s (8) () Where tn Fnlly; l l l l s s s s s s P lg s s P P lg P lg lg () 5. SMULATON RESULTS The propose openston shee for four-phse syste hs een erfe y sulton. n ths seton, the sulton results wll e presente n susse. A. Four-phse fe wre syste The syste shown n Fg. hs the followng speftons. The oltges s,,, Z,,, ) re gen elow- n penes s.5sn(t */ ) (),,, Correspons to phse,,, respetely Z Z j, Z j8, Z 5 j9 j4 (4) 96 etor@ee.o

7 Lo Blnng n Power Ftor Correton for Multphse Power Systes n the sulton results, the syste works wth unlne lo for one yle (. se) n runs for nother fe yle (. se) wth the propose openstors. t n e seen fro Fg.4 () n Fg. 4 () tht the soure urrents ( sp p,,, ) n lo urrents ( lp p,,, ) re equl n unlne When Copenstor s off urrents ( p (p=,,,)) eoe unlne orngly s shown n Fg.4(). Fgure 4 4-phse 5-wre supply syste wth n wthout openstor The nstntneous powers (soure & lo powers) n neutrl urrents (soure & lo neutrl urrents) re plotte n Fg. 5. t n e seen fro Fg. 5() tht efore openston, tht s, when openstor s swthe off, soure power ( P s ) n lo power (P l ) re equl n gntue n oslltng n nture ue to unlne n lo urrents. But fter openston when openstor s turne on the oslltng oponent of power n soure ttns stey stte lue s n e seen fro Fg. 5 () whle lo power s oslltng n nture s shown n Fg. 5 (). The power eelope n the openstor (P ) urng ts presene s lso foun unlne n shown n Fg. 5().Moreoer, the soure neutrl urrent ( sn ) ttns zero lue when the openstor s turne on n n e seen fro Fg. 5() s t lnes the soure urrents. t n thus e nferre tht the su of the nstntneous openstor urrents s equl to lo neutrl urrent ( l n ). Fgure 5 rton of power n neutrl urrent for 4-phse 5- wre supply syste The rton of o-phsors-oltge n urrents shows unty power ftor operton wth openstor s t s eent fro Fg. 6 t n e seen fro (8) tht penes re unlne n he rete eleents, ut the urrents re not only lne ut lso operte t unty power ftor wth openstor 97 etor@ee.o

8 . K. Trpth n Prof. (Col.) G.Sngh Fgure 6 ()-() (:) sle soure oltge (sol lne) soure urrents (she lne) lo urrents (hr sol lne) 5- wre supply syste. B. Lo openston for phse outges The ultphse los lke otor plty to operte wth phse outges n t hs egre perforne soure sees n unlne operton n therefore other los onnete to suh soure get ffete. The propose Copenstor n e use for lo openston for phse outges stsftory. The results re shown n Fg.7 to Fg.8 Fgure 7 rton of lo urrents, soure urrents n openstor urrents when two phse (, ) re out (fro lo se) fro 4-phse 5-wre syste Fgure 8 rton of power n neutrl urrent for the phse outge (,) of lo for 4- phse 5-wre supply syste 98 etor@ee.o

9 Lo Blnng n Power Ftor Correton for Multphse Power Systes t s foun tht fro fg (7) n fg (8) tht the soure urrents n power re lne When Copenstor s on. 6. CONCLUSON A etho for lo lnng n power ftor orreton on soure se for 4-phse (ultphse) lo rut s Propose n ths pper The propose shee hs een foun to e sutle for unlne long n phse outge soure oltges, lo urrents, soure urrents, neutrl urrents n openstor urrents hs een osere urng non-openstng n openstng pero. The rtons of the lo, soure n openstor powers re nlyze. t n e onlue tht 4-phse (ult-phse) syste equppe wth ult-phse openstor n work wth phse outges n unlne long. REFERENCES [] E. A. Klgsh n C.M. Ong, Hgh phse orer nuton otors- Prt-- Desrpton n theoretl onsertons, EEE PAS-, no. pp. 47-5, 98 [] E. A. Klgsh n C.M. Ong, Hgh phse orer nuton otors-prt-- Experentl results, EEE PAS-, no., pp.54-59, 98 [] Y. Zho, n T.A. Lpo, Moellng n ontrol of ultphse nuton hne wth struturl unlne, Prt- -Mhne oelng n ultensonl urrent regulton, EEE Trns, Energy onerson, EC-, no., pp , 996. [4] H. A. Tolyt n H. Xu, A noel ret torque ontrol (DTC) etho for fe phse nuton hne Pro. Apple Power Eletrons onferene & Syposu (APEC)-, Annul EEE Conf., pp.6-68,. [5] C. B. Jon, C. Césr e Azeeo, A. M. N. L, n L. A. Rero, Onlne estton of the sttor resstne n lekge nutne of fourphse nuton hne re, EEE Trns. On Power Eletrons, ol. 9, no., pp. -5, 4. [6] J.Apsley n S. Wllson, Anlyss of ultphse nuton hne wth wnng fults, EEE Trnstons on nustry ppltons, ol. 4, no., pp , 6. [7] H. Akg,Y. Knzw, K. Fugt n A. Ne, Generlze theory of nstntneous rete power n ts pplton, Eletrl Engg. n Jpn, ol., no.4, pp , 98. [8] H. Akg, Y. Knzw n A. Ne, nstntneous rete power openstors oprng swthng ees wthout energy storge oponents, EEE Trns. n. Appl., ol. A-, no., pp. 65-6, 984. [9] H, Akg, A. Ne n S. Atosh, Control strtegy of te power flters usng ult oltge-soure PWM onerter, EEE Trns. n. Appl. ol.a-, no., pp , 986 [] M. Z. Elsek, Blnng of unlne los usng stt r openstors, Eletr..Pow. Syst. Res., (), pp. 7-48, 987. [] H. Wtne, R. M. Stephn n M. Arees, New onepts of nstntneous te n rete powers n eletrl sy stes wth gener los, EEE Trns. On Power Delery, ol. 8, no., pp , 99. [] A. Kern n G. Shroer, A noel pproh to power ftor ontrol n lnng proles, Pro., EEE, ECON, 48-4, etor@ee.o

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