A Series Dynamic Resistor Based Converter Protection Scheme for Doubly-Fed Induction Generator during Various Fault Conditions

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1 A S Dynac Ro Bad Con Pocon Sch fo Doubly-Fd Inducon Gnao dung Vaou Faul Condon Jn Yang, Sudn Mb, IEEE, John E. Flch, and John O Rlly, Sno Mb, IEEE Abac Th pap popo a nw con pocon hod, paly bad on a dynac o (SDR, ha aod h doubly-fd nducon gnao (DFIG conol bng dabld by cowba pocon dung faul condon. A cobnd con pocon ch bad on h popod dynac o and connonal cowba analyd and dcud. Th an pocon adanag a du o h opology whn copad wh cowba and DC-chopp pocon. Vaou faul o-cun condon (boh ycal and aycal a analyd and ud o dgn h pocon n dal, ncludng h wchng agy and coodnaon wh cowba, and anc alu calculaon. PSCAD/EMTDC ulaon ul how ha h popod hod adanagou fo faul o-cun pocon, pcally fo aycal faul, n whch h adonal cowba pocon ay alfuncon. Indx T S dynac o (SDR, con pocon ch, doubly-fd nducon gnao (DFIG, faul d-hough (FRT, wnd pow gnaon.,, ψ NOMENCATURE Volag, cun and flux co. V, V Sao, oo olag aplud. R, R Sao, oo anc.,, l, l Sao, oo lf- and lakag nducanc. Magnzng nducanc.,, Synchonou, oo and lp angula fqunc.,, Sao, oo and cobnd conan. P, Q Sao d ac and ac pow., Sao and oo ubcp. n Nonal alu ubcp. I. INTRODUCTION ARGE-SCAE offho wnd fa a gadually gowng all aound h wold, pcally n Euop wh offho wnd ouc a ch and locad n hallow wa. By, % of pow conupon n Euop wll b uppld fo nwabl ouc. Th alzaon of h abou plan l haly on h lag-cal offho wnd fa. Fo h UK ag, offho wnd fa wll conbu a uch a J. Yang and J. O Rlly a wh h Dpan of Elconc and Elccal Engnng, Uny of Glagow, G 8T, UK (-al: j.yang@lc.gla.ac.uk, j.olly@lc.gla.ac.uk. J. E. Flch wh h Dpan of Elconc and Elccal Engnng, Uny of Sahclyd, G XW, UK (-al: john.flch@.ah.ac.uk. 9.4% []. Th now plannng fo o han 3 GW of offho wnd fa capacy n h Euopan a by 5 - alo 3 o han h cun nallaon []. Thfo, h lably of offho wnd fa nd o b ad n dal bcau of h coly annanc and pa n h offho nonn. Th lably dbud bwn h wnd ubn, h wnd pow gnaon y, h collcon gd and h anon y [3]. Fo wnd pow gnaon y, h doubly-fd nducon gnao (DFIG, wh aabl wnd pd ackng pfoanc, and laly low co copad o fully-ad con wnd pow gnaon y,.g. pann agn ynchonou gnao (PMSG, a popula wnd gnaon concp. How, a gnfcan dadanag of h DFIG ulnably o gd dubanc bcau h ao wndng a conncd dcly o h gd hough a anfo and wchga wh only h oo-d buffd fo h gd a a paally-ad con. So a o poc h wnd fa fo nupon du o onho gd faul and wnd fa faul, cowba poc h nducon gnao and aocad pow lconc. Th wdly-ud n ndual applcaon. A ajo dadanag of cowba pocon ha h ood con (RSC ha o b dabld whn ung h cowba and h gnao conu ac pow ladng o doaon of gd olag. In ln wh dlopng faul dhough (FRT qun, an ac cowba conol ch popod [4], [5] o hon h h cowba n opaon bu h do no aod h ac pow conupon. So ach dlopd a nw faul conol agy [6] o a faulolan gd-d con opology [7]. How, h ak h conol y coplx o nca h u wh conol coodnaon bwn noal and faul opaon. A opology can dop oo ccu olag hnc lng h cun, and an alna o cowba pocon. How, o h auho knowldg, h ha bn no publhd lau on a opology pocon ch. Thfo h ach a pocon fo ffc ubn and con pocon dung aou faul condon. Th pap ogand a follow. In Scon II, h xng pocon ch fo aabl-pd wnd ubn gnaon y, ncludng DFIG and pann agn ynchonou gnao, a uad. Thn a pocon ch wh dynac o conncd o h oo wndng popod. Th faul ha can occu n wnd fa and h cun n h oo wndng of DFIG a dcud n dal

2 a h ba of h con pocon ch dgn: faul oo cun xpon a gn hocally and wh ulaon ul; and h dffnc bwn oo cun chaacc fo ycal and aycal faul dcud whch hghlgh h adanag dynac o a h pay pocon of h con. In Scon IV, a nw con pocon ch cobnng h dynac o and h cowba noducd. Analy and dcuon of PSCAD/EMTDC ulaon a podd n Scon III and V. II. CONVERTER PROTECTION SCHEMES FOR DFIG A. Cowba Pocon Th paln DFIG pocon ch cowba pocon. A cowba a of o ha a conncd n paalll wh h oo wndng on occunc of an nupon, bypang h oo-d con. Th ac cowba conol ch connc h cowba anc whn ncay and dabl o u DFIG conol. Fo ac cowba conol ch, h conol gnal a acad by h oo-d con dc (whch a uually IGBT. Th ha olag and cun l ha u no b xcdd. Thfo h oo-d con olag and cun a h ccal gulaon fnc. Th DC-lnk bu olag can nca apdly und h condon, o alo ud a a onod aabl fo cowba ggng. Bdconal hyo [8], GTO [5], [9] o IGBT [] a ypcally ud fo cowba wchng. B. DC-Chopp In [5], [] a bakng o (DC-chopp conncd n paalll wh h DC-lnk capaco o l h ochag dung low gd olag. Th poc h IGBT fo oolag and can dpa ngy, bu h ha no ffc on h oo cun. I alo ud a pocon fo h DC-lnk capaco n full ad con opolog, fo xapl, pann agn ynchonou gnao []. C. S Dynac Ro (SDR In a la way o h dynac bakng o [3], whch ha bn ud n h ao d of gnao, a dynac o popod o b pu n wh h oo ( dynac o and h l h oo o-cun. Bng conolld by a pow-lconc wch, n noal opaon, h wch on and h o bypad; dung faul condon, h wch off and h o conncd n o h oo wndng. Th dffnc bwn h dynac o and h cowba o DC-lnk bakng o opology. Th la a hun-conncd and conol h olag whl h dynac o ha h dnc adanag of conollng h cun agnud dcly. Moo, wh h dynac o, h hgh olag wll b had by h anc bcau of h opology, o h nducd oolag ay no lad o h lo of con conol. Thfo no only conol h oo oolag whch could cau h oo-d con o lo Shun- Ro DC-Chopp conol, bu, o gnfcanly, l hgh oo cun. In addon, h ld cun can duc h chagng cun o h DC-lnk capaco, hnc aodng DC-lnk oolag. So wh h dynac o, h oo-d con do no nd o b nhbd dung h faul. Th cowba adqua fo pocon of h wnd ubn y dung gd faul n on-ho dlopn. Th nflunc of poaly long oo-d conol of DFIG can b nglcd whch no pnly h ca fo lag-cal offho wnd fa. Th opology aghfowad nough o l h o-cun and ha oolag bu h appa o b no lau ngang h u. To how h pocon ch and h nacon wh h oo ccu, h oo qualn ccu dcbd f wh h gnal Pak odl of nducon gnao. Fo h olag and flux quaon of nducon gnao n a ac aoond fnc fa [4]: dψ = R ( d dψ = R jψ ( d ψ = (3 ψ = (4 wh pod by h gd. Th oo olag conolld by h oo-d con and ud o pfo gnao conol. Fo (3 and (4 w can lna and oban an xpon whch ubud no (; lnang ψ g DC-lnk d RSC Shun- Ro Cowba Roo = j ψ R j d d d.(5 Dfnng h lakag faco a σ =. (6 Thn u a olag ouc o pn h olag du o h o ao flux poduc d o = j ψ. (7 d So (5 bco d = o R σ j d. (8 Th oo olag n (8 can b xpd n a oo fnc j fa (.. ulply boh d by d = o R σ. (9 d Th h laonhp bwn oo olag and cun. So h oo qualn ccu oband and hown wh all h abo pocon ch n Fg.. R σ Bypa Swch S-Ro S Dynac Ro Fg.. DFIG oo qualn ccu wh all pocon ch hown. o

3 III. DFIG ROTOR CURRENTS DURING FAUT CONDITIONS DFIG oo cun und h-pha ho-ccu faul ha bn hooughly analyd. In [5], xac xpon of ao and oo cun dung h ho-ccu a dd ahacally. Th appoxa axu ao faul cun xpon wa alo dcud fo h analy of DFIG phycal pon wh cowba pocon [8]. How, h ha bn no analy of faul cun dung l ou olag dp o aycal dubanc. Nonhl, h poan fo h dgn of DFIG pocon y. In h pap, h oo cun xpon dung aou faul condon wll b dducd on h ba of h analy of [4], [6]. Th pha a olag xpon da ( a ( = R{ o} R a ( σ. ( d Th can b wn a a lna dffnal quaon fo a ( R a ( a ( = [ a ( R{ o} ] ( σ σ wh wh con n opaon, l a (=V co( β, β h pha a oo olag angl a h nan h faul occu. A. Sycal faul condon Fo a ycal olag dubanc on h ao d, f h a h-pha p aplud chang fo V o ( pv (p h olag dp ao, n (9 can xcd h axu o olag ha h oo con can gna, whch cau h falu of cun conol. Th olag [6] j pv o = ( p V j. ( j Wh conan dfnd a = σ R ; = R ; = ( ( (3 ( can b plfd by ong /, whch y all bcau of h all ao anc of h gnao, o j j o V ( p ( p. (4 Fo ( and (4, h fnal xpon of a ( can b old and ddd no fou coponn ( = (5 a DC wh h coponn a DC = a ( V co β V ( p σ ( (6 f V ( p σ = V co( n( β (7 β σ = V ( p σ (8 f n n( co( ( ( V. (9 n = ( p co( n( σ Th coponn a ld n TABE I wh fquncy and dcayng- conan chaacc. TABE I SYMMETRICA FAUT ROTOR CURRENT COMPONENTS Coponn Fquncy Dcayng- conan DC DC - f - n B. Aycal faul condon Fo aycal faul, h ao olag ddd no h pa: po, nga and zo qunc coponn, n h u of ycal coponn hoy [6]: j j = V V V ( Thn n (9 can alo b xpd a o o = ( n wh j = V ( j ( = V ( (3 j n j ψ n (4 Th coponn V, V, V, and ψ dpnd on h yp of n faul. Sngl-Pha Volag Dp: Pha a uff a olag dp. Th po, nga and zo qunc coponn of h ao olag a V = V ( p / 3 (5 V = V ( p / 3 V = V ( p / 3 wh p h pha a olag dp ao du o h faul. So h abo coponn a j (6 = V ( p / 3 j ( = V ( p /3 ( (7 Fo h naual flux nal alu analy n [6] V p ψ = ( / 3 (8 n hnc o n j V ( 3 j p. (9 p V 3 j p V ( 3 j( (3 j j V ( p 3 Fo ( and (3 h fnal xpon of a ( can b old and ddd no f coponn a ( = DC (3 n wh h coponn a old a: p DC = a ( V β V σ ( co 3 (3 p V ( σ 3 ( ( 3 p

4 = V co( β n( β σ V = p co( n( 3 ( ( σ σ p 3 ( (33 (34 = V ( co( ( (35 V ( n ( (( n = ( p co( n( 3 σ (36 Pha-o-Pha Faul: H pha b and c a ho ccud ladng o a olag dp a h nal. Thn h po, nga and zo qunc coponn of h ao olag a V = V ( p / (37 V = V ( p / V = V ( p / wh p h pha b and c olag dp ao du o h faul. Alo, h nal alu of naual flux [6]: V p ψ n = (38 Th cun xpon n h ca la o h nglpha faul ca, wh h a f coponn, bu dffn aplud. Th coponn a old a: DC = a ( V co V σ ( (39 p V ( ( p σ ( β p = V co( β n( β σ V ( ( = p co( n( σ p = V ( co( ( σ ( n ( n ( (( (4 (4 (4 = V ( p σ co( n(. (43 Th coponn a ld n TABE II wh fquncy and dcayng- conan chaacc: TABE II ASYMMETRICA FAUT ROTOR CURRENT COMPONENTS Coponn Fquncy Dcayng conan DC DC - - ( - n (a (b (c (d Roo cun (pha-a (p.u. Roo cun (pha-a (p.u. Roo cun (pha-b (p.u. Roo cun (pha-b (p.u Sulaon Thocal Sulaon Thocal Sulaon Thocal Sulaon Thocal ( Fg.. Th copaon of ulaon and hocal oo cun dung faul condon (fo.5: (a h-pha.p.u. olag dp; (b h-pha.6p.u. olag dp; (c ngl-pha (pha a olag dp of.p.u.; (d pha-o-pha (pha b o c ho ccu. Th faul oo cun a ulad n PSCAD/EMTDC o copa wh h analy, a hown n Fg.. Th gnao paa a hown n h Appndx, and h oo d con conolld ung a olag gulang coconoll. Th ulaon ha h oo-d con conncd whn faul occu. Each faul dplay dffn fquncy coponn and chaacc. Th h-pha ho-ccu faul cau an abup chang a h on h faul wh hgh pak alu bu wh laly ho duaon, Fg. (a and Fg 3(a. How, fo h l ou olag dp and aycal faul, Fg (bd, h hgh agnud, hgh fquncy ocllaon ak pobl o wch off h cowba pocon. To poc h y, h con ha o b nhbd and hn h DFIG abob ac pow fo h gd, whch adly affc gd coy. Th copaon how ha h analy n accodanc wh hoy and ald fo h udy of h faul condon. Thfo wll conbu o h con pocon ch dgn n Scon IV. All h-pha oo cun a hown n Fg. 3. Th a ulaon y wll alo b ud fo h pocon ch fcaon ha follow.

5 , abc I h_sdr > S Dynac Ro ON (a (b, abc I h_cb > AND Cowba ON Roo Sd Con OFF Cowba OFF Roo Sd Con ON AND S Dynac Ro OFF _dlay = π/( T (c Fg. 3. Th-pha oo cun dung dffn faul condon (fo.5: (a h-pha.p.u. olag dp; (b h-pha.6p.u. olag dp; (c ngl-pha (pha a.p.u. olag dp; (d pha-o-pha (pha b o c ho ccu. IV. PROTECTION SCHEME BASED ON SERIES DYNAMIC RESISTOR Th abo oo faul cun analy and ulaon hghlgh a ajo dffnc bwn ycal and aycal faul cun. Fo ycal faul, h oo cun nca abuply boh a h bgnnng and h nd of h faul. Th cowba nd only wch on fo a ho. Fo aycal dp, h cowba do no ol h pobl bcau nd o b ac houghou h duaon of h dp, qung h gnao o b dconncd fo h gd. Th can b xpland by h dffnc n flux coponn fo dffn faul [6]. In h con, a nw pocon ch bad on a dynac o popod whch alo cobn and coodna h xng cowba and DC-chopp pocon. A dynac o ud a h pay pocon, wh h cowba ccu ud f h dynac o canno poc bcau of a doang uaon. Th cowba ngagd only a h bgnnng o h nd of h faul, f qud. Th DCchopp ud fo DC-lnk oolag laon. A. Swchng Sagy I obd n h abo con ha aycal faul a o hazadou han ycal faul fo h DFIG bcau of h connuou o-cun n h oo. Fo h abo ocun analy a wchng agy dd o dn whn o ngag h pocon au ung cun hhold. Pocon ngagd: Th olag chang no a abup a h cun and can b had by h dynac o. Fo h DC-lnk olag, chang can b fuh ducd by h DCchopp. Thfo, only oo cun a onod fo dynac o and cowba pocon. Pocon dngagd: Th pocon hl can b n a dubanc. To aod h pocon wchng fqunly bcau of h hgh fquncy coponn of oo cun, h wch off dlayd fo a pod of h hgh fquncy coponn,.. _dlay = π/( af all h hpha cun dca blow h hhold alu. Th fnal wchng agy hown n Fg. 4. (d DC V h_dc < DC-chopp ON DC-chopp OFF Fg. 4. Th cobnd con pocon wchng agy. B. S Dynac Ranc Calculaon Ranc alu a calculad fo h o ou condon (wh h hgh pak cun alu: ycal olag dp up o.p.u.. Th oo cun xpon a (5 o (9. Du o h all ao anc, h followng appoxaon a / ad: ;. Thn h cun coponn a xpd a a ngl gonoc funcon a: DC n = a ( V co σ ( (44 V ( σ = V n( β ϕ σ β (45 = (46 f = V ( n( ϕ σ (47 wh ϕ = an Condng h aplud of ach coponn a h axu cun alu: a,ax = a ( V ( σ. (48 V V ( σ σ Alo, h bounday condon a a,ax I h_sdr ; V V h_rsc. (49 Thfo, (48, (49 an quaon wh can b old. Wh h pocon ch σ = (5 R R pocon Thn h ccal anc alu R pocon can b calculad. If h oo faul cun ll canno b ld ffcly, h cowba can b ud a fuh pocon. Th oal anc R pocon, nclud R SDR and R CB. Th cun-lng funcon podd by h dynac o, hnc h ccal ca of cowba anc h olag aco u b whn h oo olag l, fo hun conncon: R CB,ax V,ax. So h cowba anc a all conbuon o h oal R pocon.

6 Th pl han ung cowba pocon alon, wh h anc ha a low and upp l. Th nu alu cd by h oo wndng cun l, whl h axu by h olag l a h con nal [8]. Fo (48, (49, =.4p.u.; R pocon =.987p.u. =.59Ω. Thn h lcd anc alu a R SDR =.5Ω, R CB =.9Ω. Th alu of DC-chopp anc no o ccal a only lad o h DC-lnk olag, o h choo R DCC =.5Ω. V. SIMUATION RESUTS Th popod con pocon hod fd by PSCAD/EMTDC ulaon. Th gnao paa a ld n h Appndx. Th faul ulad a: a h-pha olag dp of.95p.u. fo.; a ngl pha (pha a goundng fo.; 3 a wo-pha ho-ccu (pha b o c fo.; and 4 a h-pha olag dp of.6p.u. fo.. Th hhold alu fo calculang R SDR and R CB a a I h_sdr =.5p.u., I h_cb =.8p.u.. Roo lp =.p.u. pcdng h faul. (a (b (c (d (a ( (b (f (c (g (d (h ( ( (f (g (j (h (k Fg. 5. Th-pha.95p.u. olag dp fo. whou pocon: (a hpha ao olag a,b,c (p.u.; (b h-pha ao cun a,b,c (p.u.; (c h-pha oo cun a,b,c (p.u.; (d pha-a oo olag a (p.u. and pha-a RSC olag c,a (p.u.; ( DC-lnk olag DC (p.u.; (f ao d ac pow P (p.u. and ac pow Q (p.u.; (g oo pd (p.u.; (h lccal oqu T (p.u. and chancal oqu T (p.u.. Fg. 6. Th-pha.95p.u. olag dp fo. wh con pocon: (a h-pha ao olag a,b,c (p.u.; (b h-pha ao cun a,b,c (p.u.; (c h-pha oo cun a,b,c (p.u.; (d SDR wchng gnal S SDR; ( cowba wchng gnal S CB; (f DC-chopp wchng gnal S DCC; (g pha-a oo olag a (p.u. and pha-a RSC olag c,a (p.u.; (h DC-lnk olag DC (p.u.; ( ao d ac pow P (p.u. and ac pow Q (p.u.; (j oo pd (p.u.; (k lccal oqu T (p.u. and chancal oqu T (p.u..

7 A. Sycal Faul Condon Fg. 5 and 6 how h y pon o a.95p.u. olag dp fo. wh and whou pocon pcly. In h ulaon whou pocon, h oo-d con blockd dung h faul. Th oo cun ach aound.p.u. fo h o ou pha. DC-lnk olag and oo pd boh nca unl h faul clad. ag lccal oqu flucuaon occu. In Fg. 6, dynac o wchd n n oal o l h oo cun. Dung h coy of h faul, cowba wchd n fo 5 wh h dynac o conncd a h oo cun nca byond h cowba hhold. Th ulaon ul how ha wh dynac o pocon, h f oqu pak afly aodd, whl cowba hlpful fo pocon dung faul coy. Th oo cun aplud ld whn.5p.u., a qud. Th alo c h DC-lnk olag nca (l han.5p.u. n Fg. 6. Th DC-chopp funcon no qud. Th oo pd nca ffcly and, fo.p.u. o.7p.u. (.p.u. fo whou pocon ca. Th lag 5.p.u. oqu flucuaon a h a of h faul aodd; copa Fg. 5 o Fg. 6 wh h dynac o. How, a 7.p.u. oqu flucuaon occu dung h faul coy pha n Fg. 6. Th du o h cowba pocon wchng n a a fuh pocon au. Th nddual cowba and SDR oqu pfoanc wll b copad n Pa C whch how ha all of h 7.p.u. oqu pulaon ha occu a faul coy du o h cowba ccu, Fg. (d and (. Alhough h no oo olag onong n h wchng agy, ll ld ffcly o h alu bfo h faul bcau of h olag hang ably of h dynac o. Th oo olag dplay wchng fquncy coponn du o h pul wdh odulaon (PWM of h oo-d con. Th hgh olag had aco h o and h con whch ul n a low con d olag ( c,a n Fg. 7. ag ann happn dung h faul clang anly du o h pac of cowba pocon wchng, bu ogh wh dynac o pocon, h dubanc dappa af abou.5. I hould b nod ha h cowba ud n h pacula ca, bu no a ncay qun und all faul. B. Aycal Faul Condon Fg. 8 and 9 how h y pon dung aycal faul condon. Th oo cun a alo ld whn.5p.u.. Fo h pha-a faul n Fg. 8, h dynac o and cowba pocon wchng n a la o h ycal faul condon. How, h on pod of DC-chopp wchng bcau of h gadual nca of DClnk olag o.p.u.. Inad of ncang, h oo pd dca bcau h DFIG ll und conol wh ac pow uppld o h gd. An opd condon aodd a h lccal oqu balanc h chancal oqu fo h wnd ubn blad y. Fg. 7. Th oo olag a (p.u. and oo-d con olag c,a (p.u. copaon (zood fo o.. (a (b (c (d ( (f (g (h ( (j (k Fg. 8. Pha a.p.u. olag dp fo. wh con pocon: (a hpha ao olag a,b,c (p.u.; (b h-pha ao cun a,b,c (p.u.; (c h-pha oo cun a,b,c (p.u.; (d SDR wchng gnal S SDR; ( cowba wchng gnal S CB; (f DC-chopp wchng gnal S DCC; (g pha-a oo olag a (p.u. and pha-a RSC olag c,a (p.u.; (h DC-lnk olag DC (p.u.; ( ao d ac pow P (p.u. and ac pow Q (p.u.; (j oo pd (p.u.; (k lccal oqu T (p.u. and chancal oqu T (p.u..

8 (a (b (a Q (p.u SDR CB SDR CB (c (b Q (p.u (d (c W (p.u CB SDR ( (f (d T (p.u. CB (g (h ( (j (k Fg. 9. Pha b o c ho ccu fo. wh con pocon: (a hpha ao olag a,b,c (p.u.; (b h-pha ao cun a,b,c (p.u.; (c h-pha oo cun a,b,c (p.u.; (d SDR wchng gnal S SDR; ( cowba wchng gnal S CB; (f DC-chopp wchng gnal S DCC; (g pha-a oo olag a (p.u. and pha-a RSC olag c,a (p.u.; (h DC-lnk olag DC (p.u.; ( ao d ac pow P (p.u. and ac pow Q (p.u.; (j oo pd (p.u.; (k lccal oqu T (p.u. and chancal oqu T (p.u.. Th pha b o c ho-ccu n Fg. 9, n of faul cun, l ou han n h ngl-pha ca. Th no nd fo boh cowba and DC-chopp opaon. Th dynac o ffc n h condon. Bu n of ao olag, h o ou han fo a ngl-pha faul. ( T (p.u. SDR ( Fg.. Sy pon copaon bwn cowba and dynac o pocon, olag dp of.6p.u. fo : (a ao-d ac pow Q (p.u.; (b zood ac pow Q (p.u.; (c oo pd (p.u.; (d lccal oqu T (p.u. wh CB pocon; ( lccal oqu T (p.u. wh SDR pocon. Th a uch lag pow and lccal oqu flucuaon dung h faul. Th ul n gadual nca of oo pd, fo.p.u. o.p.u. bu h no ou. Th wo aycal condon ul n flucuaon af ao olag coy. Alhough o of h aabl a und conol, h flucuaon hould b udd n o dal. C. Pfoanc Copaon bwn Cowba and SDR Th pfoanc of h cowba and h dynac o pocon ch a copad. Th ac pow, lccal oqu and oo pd of h DFIG y a ulad and copad n Fg.. Boh of h wo ag xpnc ac pow and lccal oqu flucuaon dung h faul. How, fo cowba pocon, hy a uch lag. Fg. (b xpandd o how h ac pow upply. I can b n ha wh h oo-d con conncd wh h dynac o pocon ch, no ac pow abobd. How, fo cowba pocon, h aynchonou achn abob ac pow, up o.p.u.. So n of gd olag coy, h dynac o pocon ha a gnfcan adanag.

9 Th ac pow and lccal oqu ppl a lag wh dynac o pocon copad o cowba pocon. Th du o h hgh anc n h oo wndng and DFIG conol y pfoanc dung faul, whch nd fuh xploaon. How, cla ha h pak oqu ha occu a cowba un-on and un-off gnfcanly hgh han ha fo h dynac o. Th lad o h lag oqu flucuaon n n Fg. 6 whn h cowba ngagd. Fo oo pd chang hy a abou.p.u. dffn a h pak po o coy. Th dynac o duc h oo o-pd o ffcly han h cowba ccu. Mo poanly, h dynac o ha a uch all pac han h cowba, pcally dung wchng-off. Ipop cowba wch-off agy (whou h coodnaon of conoll fnc ng [4] can cau fqun wchng whch affc faul coy. Th can alo b n fo h copaon of olag coy n Fg. 8 and 9. Whou cowba wchng, h olag coy fo h wo-pha hoccu how nal flucuaon. VI. APPICATION DISCUSSIONS A. Th Swch T of h Bypa-Swch In paccal applcaon, h wch ay b an u, pcally fo ou faul pocon and coy whn fa wchng pon qud.g., o cowba hyo wch canno nup h cun bfo zo-cong [8]. Th wll nflunc h pocon pfoanc. In h abo ulaon, wchng of h cowba and dynac o pow-lconc wch a condd by dablng h npolaon n PSCAD/EMTDC. Th ol h conflc bwn da wchng-opaon wh ulaon p. Th ulaon p a µ, o h acual wch fo IGBT µ, whch nough fo h IGBT n applcaon (coonly al µ [7]. B. Swch Noal Opaon o Th dynac o h alzd by a powlconc wch. How, h bypa wch ha clod dung noal opaon wll poduc addonal lo, pcfcally dc on-a lo. Bu copad o h ao d bakng o bypa-wch [3], h fa low du o h low pow ang on h oo d. VII. CONCUSION Con pocon ncay fo DFIG wnd pow gnaon y dung faul condon. In h pap, aou o pocon ch a wd. Th pupo of a dynac o o aod h fqun u of cowba hoccu, o axz h opaon of h oo-d con, and o duc oqu flucuaon dung pocon opaon. Th oo cun dung aou faul condon a dcud and cun xpon a gn o nuc h dgn of h pocon ch. Ranc calculaon fo h dynac o and cowba ung h xpon of axu oo cun a dcbd. Th dynac o can opa wh h oo-d con conol funconng. Fo h conol of h gd-d con o DC-lnk bu olag, h upon can b ho han fo a y wh noal ac cowba pocon. Th hlpful fo ung noal conol and pod ac pow fo gd olag uppo. Dung h poc, npcon of h ac pow, lccal oqu, and oo pd flucuaon how ha h popod hod nhanc DFIG faul d-hough capably. APPENDIX TABE III GENERATOR PARAMETERS Paa Valu Paa Valu Rad pow P n MW Rao N /N.63 Rad ao olag V n 69 V Ina conan H 3.5 Rad fquncy f 5 Hz Pol pa no. P p Sao lakag nducanc l.5 p.u. Sao anc R.5 p.u. Roo lakag nducanc l. p.u. Roo anc R.55 p.u. Magnzng nducanc p.u. REFERENCES [] Bh Wnd Engy Aocaon. Offho wnd. Aalabl: hp:// nfo.hl [] Th Euopan Wnd Engy Aocaon. Euopan Sac. Aalabl: hp:// [3] P. J. Tan, J. Xang, and F. Spnao, Rlably analy fo wnd ubn, Wnd Engy, 7, ol., pp. -8, [Onln]. Aalabl: hp://www3.ncnc.wly.co/cgbn/fullx/74/pdfstart [4] J. Mon, and S.W.H. d Haan, Rdhough of wnd ubn wh doubly-fd nducon gnao dung a olag dp, IEEE Tan. Engy Con., ol., no., pp , Jun. 5. [5] I. Elch, J. Kchann, J. Foann, S. Mull-Englhad, and H. Wd, Modlng of wnd ubn bad on doubly-fd nducon gnao fo pow y ably ud, IEEE Tan. Pow Sy., ol., no. 3, pp , Aug. 7. [6] D. Xang, R., P. J. Tan, and S. Yang, Conol of a doubly fd nducon gnao n a wnd ubn dung gd faul d-hough, IEEE Tan. Engy Con., ol., no. 3, pp , Sp. 6. [7] P. S. Flanny and G. Vnkaaaanan, A faul olan doubly fd nducon gnao wnd ubn ung a paalll gd d cf and gd d con, IEEE Tan. Pow Elcon., ol. 3, no. 3, pp. 6-35, May 8. [8] J. Mon and S. W. H. d Haan, Sho-ccu cun of wnd ubn wh doubly fd nducon gnao, IEEE Tan. Engy Con., ol., no., pp. 74-8, Ma. 7. [9] P. Zhou and Y. H, Conol agy of an ac cowba fo DFIG bad wnd ubn und gd olag dp, n Poc. In. Conf. Elccal Machn and Sy. 7, Soul, Koa, Oc. 8-, 7. [] M. Rodíguz, G. Abad, I. Saaola, and A. Glab, Cowba conol algoh fo doubly fd nducon gnao dung olag dp, n Poc. h Eu. Conf. Pow Elcon. Appl., Ddn, Gany, Sp. -4, 5. [] I. Elch, H. Wd, and C. Fl, Dynac bhao of DFIG-bad wnd ubn dung gd faul, n Poc. Pow Con. Conf., Nagoya, Japan, Ap. -5, 7. [] J. F. Conoy and R. Waon, ow-olag d-hough of a full con wnd ubn wh pann agn gnao, IET Rnw. Pow Gn., ol., no. 3, pp. 8-89, 7. [3] A. Caubook, D. J. Aknon, and A. G. Jack, Faul d-hough of lag wnd fa ung dynac bakng o (Mach 7, IEEE Tan. Pow Sy., ol., no. 3, pp , Aug. 7. [4] J. ópz, P. Sanch, X. Roboa, and. Maoyo, Dyanc bhao of h doubly fd nducon gnao dung h-pha olag dp, IEEE Tan. Engy Con., ol., no. 3, pp , Sp. 7.

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