An Optimized Ride through Protection Method for DFIG Wind Turbine during Asymmetrical Disturbance

Transcription

1 578 J. Baic. Appl. Sci. Re., ()578-58,, TextRoad Publication ISSN 9- Jounal of Baic and Applied Scientific Reeach An Optiized Ride though Potection Method fo DFIG Wind Tubine duing Ayetical Ditubance Alieza Zohooi, Rouhollah Shafaie The Cente of Excellence fo Powe Syte Autoation and Opeation, Depatent of Electical Engineeing Ian Univeity of Science and Technology, Tehan, Ian ABSTRACT In thi pape a coplete analyi fo calculating the tato flux vecto of the doubly fed induction geneato (DFIG) unde yetical and ayetical netwok ditubance wa pefoed without neglecting neithe the tato eitance no the lip fequency. The effect of diffeent fault occuence tie on the aplitude of the tato cuent i then invetigated. Conequently, an optial cowba eitance fo fault ide though potection of DFIG unde netwok ditubance i popoed by eploying the atheatical algoith of Analytic Hieachy Poce (AHP). A typical elative ipotance i elected and optiization i caied out. Siulation eult fo an optiized cowba deontated that the popoed potection contol yte can ipove the tato voltage duing the fault and the fate etieval afte the fault. Keywod: Doubly Fed Induction Geneato; Cowba Optiization; Reactive powe; Analytic Hieachy Poce;Voltage ditubance.. INTRODUCTION Recently the nube of vaiable peed wind tubine connected to the gid, epecially thoe uing doubly fed induction geneato (DFIG), i contantly inceaing. The ot ignificant advantage of thi kind of tubine eege in the ating of thei convete which i aound 5 5% of the tubine ated powe. Moeove not only cot, ize and weight collaboated with a all convete ae lowe but alo loe ae alle than the wind tubine baed on full powe convete connected to the tato []. Since the tato i diectly connected to the gid a hown in Fig., thee type of wind tubine ae o uch enitive to netwok ditubance epecially fault condition which becoe the ain poble. Fig..Scheatic of DFIG wind tubine connected to the gid A udden gid voltage dop becaue of netwok ditubance, that ae ainly yetical o ayetical fault, ceate ovevoltage and ove-cuent in the oto winding that can detoy the oto ide convete (RSC) if no pope potection ethod i conideed []. The potection ethod to deal with the poble and ipove fault ide though (FRT) capability i concealed in connecting oto winding to the cowba eito [,, 5]. The cowba ut liit the oto cuent in a way that oto teinal voltage doe not exceed fo the ated voltage. Thi ean that alle the cowba the bette it i [, ].Fo anothe point of view, a lage cowba eitance to liit the oto peak cuent i oe deiable [, ]. Hence, one of the bet and ot coon ethod fo FRT contol yte i electing the optial cowba eito. The cowba value ut be choen in the way that not only povide FRT capability of the DFIG but alo guaantee fat wind tubine etoation. Cowba optiization ethod wa patially dicued in [, 5,, 7], whee in ot of the the optiization pefoed eithe by the iteative anne o hallow one jut fo yetical thee phae fault. Theoetical ethod in finding an optial cowba wa patially dicued in [8] fo a ingle phae fault. In thi pape the autho develop the idea fo all type of netwok fault condition baed on analytical hieachy poce (AHP). Accodingly, the optial cowba i obtained. Beide, thoough analyi fo calculating the tato flux vecto of the DFIG unde yetical and ayetical netwok ditubance i pefoed without neglecting neithe the tato eitance no the lip fequency which wee not conideed in late tudie [,5,]. Siulation eult pove that the popoed potection yte can povide a high deiable FRT pefoance of the DFIG duing netwok ditubance. Coeponding Autho : Alieza Zohooi, The Cente of Excellence fo Powe Syte Autoation and Opeation, Depatent of Electical Engineeing, Ian Univeity of Science and Technology, Tehan, Ian. Eail: aliezazohoui@iut.ac.i

2 Zohooi and Shafaie. DFIGBehavio Unde Netwok Ditubance In thi ection the popoed ethod fo tato flux vecto calculation i obtained fo ayetical fault condition. Notice that fo yetical fault the ae equation ae applied by neglecting the negative equence of the tato voltage vecto in all the equation. Fo iplifying the tudy, the oto vaiable will be efeed to the tato. Hee d-q efeence fae otating at ynchonou peed i ued by []: v d R i d d d d v q R i q dt q q v d R i d d d d v q R i q dt q q Since the tato i connected to the gid diectly, the gid ipoe the tato voltagev d andv q. The oto voltage vq and vd ae foced by a RSC which contol the achine pefoance. The tato and oto flux of the d-q axi can be eached by []: d i d d i () d q i q q i () q whee and ae the tato and oto inductance, epectively and i the agnetizing inductance. Inveing () and () then ubtituting in () and () given the following equation [7]: R R. z. z v d R. d R v q z. z q v d R. R d. v z z q (5) q R. R. z z R R.. z z v d. d R R vq z. z q vd R. R ( ) d. z z v q q R. R. z z () whee z z z and z ( ) ( ) ae given a: The effect of ayetical fault in phae voltage can be tudied accoding to yetical coponent theoy. Baed on thi theoy, a thee phae voltage yte can be expeed a the u of thee coponent: poitive, negative, and zeo equence. Theefoe the tato voltage pace vecto can be decopoed into thee vecto:. j t v. j t v e v e v (9) Fo a given claical achine with yetical ipedance, the poitive equence v ceate a flux otating at the ynchonou peed and the negative equence v ceate a flux otating with agnitude of the ynchonou peed but in the oppoite diection. Alo, the zeo equence v doe not ceate any flux. Thee voltage ceate foced and natual flux epectively which i fully dicued in []. Now diffeent kind of fault condition will be invetigated though the following ubection. A. Single-Phae Fault A ingle phae fault dop the voltage. Taking into account equal ipedance fo the poitive and the negative equence, the poitive, negative and zeo coponent expeed a: V a a V ( p ) p / V a a. V. a v. p / V V. a p / The tato flux vecto afte the fault occuence can be obtained fo (5), () and () in d-q ynchonou fae a: (7) (8) () 579

3 J. Baic. Appl. Sci. Re., ()578-58, af jt d d d. e bf () jt t jt d d d. e. e. e af j t q q q. e bf () jt t j t q q q. e. e. e.8 Natual flux (pu)... X:.8 Y:.7 X:.58 Y:.89 Fig.. Nataul flux value fo diffeent tie of ingle phae fault af Whee t and t ae the tie jut befoe and afte the fault occuence epectively. bf d And d ae the tato flux vecto afte and befoe fault occuence, epectively. Note that the tato flux vecto i obtained without neglecting neithe the tato eitance no the lip fequency. The econd pat of the () and (), the te in backet, ae explaining the natual flux. It i obviou that with diffeent tie of fault occuence the natual flux i changing fo a iniu value to a axiu value, o it affect on total peliinay tato flux vecto hence the aplitude of the tato cuent change baed on thi flux value. Fig. how the natual flux vaiation fo diffeent tie of ingle phae fault in a pecific geneato that the achine paaete ae given in Appendix. Accoding to Fig. the natual flux doain ae obtained a: y n (ax) =.7 () y n (in) =.89 The effect of obtained natual flux value on the tato cuent aplitude can be een in Fig. and Fig.. Beide, the tato flux tajectoy befoe and afte the fault occuence i deontated in Fig. 5. B. Phae to phae fault The poitive, negative, and zeo voltage coponent ae a follow []: V p / V v. p / () V p / With the voltage hown in (), the coponent of the tato flux vecto can be calculated fo () and () a the latte. Fig. how the natual flux vaiation fo diffeent tie of phae to phae fault in the odel. Accoding to Fig. the natual flux aplitude ae obtained a: y (ax) =. n y (in) =. n Tie (S) 5 Stato cuent (pu)... Tie (S) Fig.. Stato cuent vaiation unde ingle phae fo in natual flux 58

4 Zohooi and Shafaie Stato cuent (pu)... Tie (S) Fig.. Stato cuent vaiation unde ingle phae fault fo ax natual flux Flux, Beta axi (pu) Flux, Alpha axi (pu) Fig. 5.Stato flux tajectoy duing ingle phae fault The effect of achieved natual flux value on the tato cuent aplitude can be een in Fig. 7 and Fig. 8. Fig.7 how that the phae to phae fault ha a agnitude of about p.u on the oto winding a well a the oto ide convete. Thi i becaue of the highe natual flux in two phae fault that i obtained in (5).Theefoe it will detoy the GSC and RSC coponent if potection ethod ae not applied to the yte.. Natual flux (pu).8... X:.5 Y:. X:.55 Y: Tie (S) Fig.. Nataul flux value fo diffeent tie of two phae fault Stato cuent (pu) 8... Tie (S) Fig. 7.Stato cuent vaiationunde phae to phae fault fo ax natual flux Alo, the tato flux tajectoy befoe and afte the fault occuence i deontated in Fig. 9. Flux, Beta axi (pu) Flux, Alpha axi (pu) Fig. 9.Stato flux tajectoy duing phae to phae fault tat at t 58

5 J. Baic. Appl. Sci. Re., ()578-58,. CROWBAR OPTIMIZATION The concept of the pai wie copaion i oiginated fo pychological eeach that becoe the bae of AHP. The AHP i ued in the ultiple citeia deciion aking application. The deciion ake in thi ethod expee linguitic pai wie copaion, at fit; then, obtain nueical pai wie copaion by electing cetain nueical cale to quantify the and eventually calculate pioity vecto fo the nueical pai wie copaion [9]. The objective function of the peent ethod i defined a below [9]: F = w I + w T + w V + w Q () e Whee w, w, w and w ae elative ipotance of noalized containt of oto cuent I, electoagnetic toquet e, oto voltage V and eactive powe Q, epectively. Note that thee paaete ae obtained by iulation of DFIG unde netwok ditubance with diffeent cowba eitance value. It hould be ention that thee quantitie ae in diffeent ange o the containt ae noalized to the inteval of -9. d - c y noal = ( x - a) + c (7) b - a Fig. (7-a) and (7-b) efe to iniu and axiu peak value of obtained paaete fo iulation, epectively and x i the value within thi inteval. Beide, c and d ae equaled to one and nine, epectively. Moeove, the weight ae calculated by AHP algoith with epect to the fact that pefeence ae elected accoding to ipotance of vaiable. Fo intance, the pefeence of oto teinal voltage i oe than oto cuent and electical toque in ode to potect the powe electonic convete in te of theal inulation. Afte calculation of the weight, the objective function i plotted whee the iniu point i an optiized cowba fo pefect DFIG pefoance duing the fault conideing le powe aboption to have a bette dynaic fo fate voltage ecovey afte the fault. In ode to have a pecie analyi of the effect of cowba value on eactive powe, oto cuent, voltage and electical toque fo finding an optiize cowba thi pape ued a fifth ode algebaic diffeential equation of DFIG []. Hee the optiized cowba eitance fo netwok ditubance fo ingle phae, phae to phae and thee phae netwok fault ae hown in Fig., Fig. and Fig., epectively. Accoding to thee figue, the optiized cowba value ae obtained a. p.u.,. p.u. and. p.u fo ingle phae fault and phae to phae fault, epectively.. EVAUATION OF THE PROTECTION CONTRO SYSTEM In thi ection iulation i caied out fo diffeent cowba value fo yetical and ayetical netwok fault condition. Notice that netwok ditubance occued at tie.. A we can ee in thee figue the optiized cowba atifie the containt. A pointed out in fig.7 and fig.8 the lowe value fo cowba caue the lage peak cuent and electical toque. A hown fig.9 an inceent in cowba eult highe oto teinal voltage duing fault. A- Syetical Fault Figue how the tato cuent aplitude vaiation unde thee phae fault fo two cowba eitance that one i the optiized cowba achieved in the lat ection. Alo, Fig. 5 i deontating the toque and active powe of the geneato duing the ae condition. A pointed out in Fig. and Fig. the lowe value fo cowba caue the lage peak cuent and electical toque aplitude. O b jectiv e F u n ctio n X:. Y: Cowba Reitance (pu) Fig..Objective function veu cowba unde ingle phae fault Fig.. Objective function veu cowba unde phae fault 58

6 Zohooi and Shafaie Stato Cuent (pu) Fig.. Objective function veu cowba unde thee phae fault Rcb=. Rcb= Tie () Fig.. Stato Cuent aplitude vaiation duing yetical fault Electical Toque (pu) 8 - Rcb=. Rcb= Tie () Fig.. Electical toque vaiation duing yetical fault 5 Rcb=. Rcb=. Active Powe (pu).5.5 Tie (pu) Fig. 5.Active powe vaiation duing yetical fault B- Ayetical Fault Figue how the tato cuent aplitude vaiation fo optiized and non-optiized cowba eitance unde ingle phae fault. Alo, Fig. 7, Fig. 8 and Fig. 9 ae peenting the toque, active and eactive powe of the DFIG duing the ae condition. Stato Cuent (pu) 5 Rcb=. Rcb= Tie () Fig.. Stato cuent aplitude vaiation duing ingle phae fault 58

7 J. Baic. Appl. Sci. Re., ()578-58, Electical Toque (pu) - Rcb=. Rcb= Tie () Fig. 7. Electical toque vaiation duing ingle phae fault Active Powe (pu) Rcb=. Rcb=. Stato Reactive Powe (pu) Tie () Fig 8. Active powe vaiation duing ingle phae fault Rcb=. Rcb= Tie (pu) Fig. 9. Reactive powe vaiation duing ingle phae fault In the ae anne the iila figue ae obtained fo phae to phae fault condition with optiized cowba potection contol yte that can be een in Fig. to Fig.. A it i hown in Fig. 9 and Fig. the bette ide though potection contol yte i obtained by the popoed cowba optiization ethod. Stato Cuent (pu) 5 Rcb=. Rcb= Tie () Fig.. Stato cuent aplitude vaiation duing phae to phae fault Electical Toque (pu) - Rcb=. Rcb= Tie () Fig.. Electical toque vaiation duing phae to phae fault 58

8 Zohooi and Shafaie Active powe (pu) Rcb=. Rcb= Tie () Fig.. Active powe vaiation duing phae to phae fault Stato Reactive Powe (pu) Tie () Fig.. Reactive powe vaiation duing phae to phae fault. CASE STUDY FOR TYPICA GRID The obtained optiized cowba duing netwok ditubance ae applied to a typical gid a it i hown in Fig.. The tato voltage aplitude vaiation duing yetical and ayetical netwok ditubance ae hown in Fig. 5 to Fig. 7, epectively. Alo, eult ae obtained with diffeent cowba value. It i hown that the optiized cowba will ipove the DFIG FRT capability and povide fate etoation epone conequently enhanced the dynaic pefoance of wind tubine afte the netwok ditubance. It can be een that fo a yetical fault change in aplitude of tato voltage i le than two othe type of ayetical fault which ae tudied in thi pape. Rcb=. Rcb=. T T Fig.. Scheatic of a typical gid.5 Rcb=. Rcb= Fig. 5. Stato voltage aplitude vaiation duing yetical gid fault Stato Voltage (pu) Rcb=. Rcb= Tie () Fig.. Stato voltage aplitude vaiation duing ingle phae gid fault 585

9 J. Baic. Appl. Sci. Re., ()578-58, Stato Voltage (pu) Rcb=. Rcb=.. CONCUSION Tie () Fig. 7. Stato voltage aplitude vaiation duing phae to phae gid fault Thi pape i focued on copehenive analyi to calculate the tato flux vecto of DFIG unde yetical and ayetical netwok ditubance. It i ipeative that the popoed analyi i caied out by conideing both the tato eitance and the lip fequency. The effect of diffeent fault occuence tie on the aplitude of the tato cuent i then invetigated. Moeove, an optial cowba eitance fo FRT potection of DFIG unde diffeent kind of netwok ditotion i popoed by applying the AHP ethod. Siulation eult pove that the novel potection contol yte can povide a high deiable FRT pefoance and enhanced dynaic behavio of the DFIG duing netwok ditubance. APPENDIX DFIG data p MW v 9 v.8 pu.8 pu X.75 pu l X. pu l X.8 pu f 5 Hz REFERENCES [] Vie E., 9. Wind Technology Tend: Why Sall Step Matte,UK Renewable Enegy Wold Magazine. [] opez J., Sanchi P., Roboa X. and Maoyo., 7. Dynaic Behavio of the Doubly Fed Induction Geneato Duing Thee Phae Voltage Dip: IEEE Tanaction Enegy Conveion. (), [] opez, J., P. Sanchi, X. Roboa and. Maoyo, 8. Wind Tubine Baed On Doubly Fed Induction Geneato Unde Ayetical Voltage Dip:IEEE Tanaction Enegy Conveion. (), -. [] Moen J. and S. W. H. de Haan, 5. Ride Though of Wind Tubine With Doubly-Fed Induction Geneato Duing a voltage Dip: IEEE Tanaction Enegy Conveion (),5-. [5] aa O., Z. iu, G.Q Vaela and J.R. McDonald, 8 Optial DFIG Cowba Reito Deign unde Diffeent Contolle duing Gid Fault: DRPT -9 Nanjing China M. Young. [] Motezapou V., H. eani and A. Abbazadeh, 9. Shot Cicuit Cuent Calculation of Doubly Fed Induction Geneato: Intenational Confeence on Electic Powe and Enegy Conveion Syte. [7] Bollen M. H. J., G. Olguin, and M. Matin, 5. Voltage dip at the teinal of wind powe intallation: Wind Enegy, 8, 7 8. [8] Peng Z. and H. Yikang, 7.Contol Stategy of an Active Cowba fo DFIG Baed Wind Tubine unde Gid Voltage Dip: Intenational Confeence on Electical Machine And Syte, Oct. 8~, Seoul, Koea. [9] DongY., Y. Xu, H. i and M. Dai, 8. Acopaative Study of the Nueical Scale and the Pioitization Method in AHP: Euopean Jounal of Opeational Reeach, (8), 9-. [] AbbazadehA.,. ean and v. Motezapou, 9. Tanient Repone of Doubly Fed Induction Geneato unde Voltage Sag Uing an Accuate Model: Confeence on Sutainable Altenative Enegy (SAE), IEEE PES/IAS, Valencia. 58