Modeling and Position-Sensorless Control of a Dual-Airgap Axial Flux Permanent Magnet Machine for Flywheel Energy Storage Systems

Transcription

1 758 Junal f Pwe Electnc, Vl., N. 5, eptembe JPE Melng an Ptn-enle Cntl f a Dual-Agap Axal Flux Pemanent Magnet Machne f Flywheel Enegy tage ytem Tng Duy Nguyen, lbet F Hck Beng *, Kng-Jet Teng *, Dn Mahna Vlathgamuwa *, an Xnan Zhang * * chl f Electcal an Electnc Eng., Nanyang Technlgcal Unvety, ngape Abtact Th pape peent the melng an ptn-enle vect cntl f a ual-agap axal flux pemanent magnet (AFPM) machne ptmze f ue n flywheel enegy tage ytem (FE) applcatn. The ppe AFPM machne ha tw et f thee-phae tat wnng but eque nly a ngle pwe cnvete t cntl bth the electmagnetc tque an the axal levtatn fce. The ppe cntllablty f the latte cucal a t can be utlze t mnmze the vetcal beang te t mpve the effcency f the FE. The meth f cntllng bth the pee an axal placement f the machne cue. An nheent pee enle beve al ppe f pee etmatn. The ppe beve elmnate the tay ence, whch n tun euce the veall weght an ct f the ytem whle mpvng t elablty. The effectvene f the ppe cntl cheme ha been vefe by mulatn an expement n a pttype machne. Keyw: Axal evtatn Fce Cntl, Dual-Agap Axal Flux Pemanent Magnet Machne, Flywheel Enegy tage ytem, enle vect cntl a δ g, g g, g f ^,, q I max J K c K p, K, K K T NOMENCATURE a electe th ple f the ytem la angle uppe an lwe agap length uppe an lwe effectve agap gan f the beve flywheel gavty etmate quantte -axe tat cuent q-axe tat cuent maxmum cuent f the machne mment netal f the flywheel Cate fact pptnal, ntegal, ffeental ceffcent tque cntant Manucpt eceve Aug. 9, ; eve Jul. 6, Recmmene f publcatn by Acate Et Jung-Ik Ha. Cepnng Auth: t..nguyen@pmal.ntu.eu.g Tel: , Fax: , Nanyang Tech. Unvety * chl f Electcal&Electnc Eng., Nanyang Technlgcal Unvety, ngape a, b, c ff lm, l m,, tat elf-nuctance t elf-nuctance tat nuctance uppe an lwe pemanent magnet thckne -axe tat flux lnkage -axe t fluxe, q q-axe tat flux lnkage f t flux lnkage tat flux lnkage magntue M af, M bf, M cf mutual nuctance μ, μ pemeablty n vacuum, elatve pemeablty N f f fctu magnetmtve fce f the t fel N numbe f tat wnng n unampe natual fequency f the ytem tat flux vect pee e t electcal pee p numbe f ple pa ξ ampng at f the ytem R tat etance R, R nne an ute au f the pemanent magnet T, T, T uppe, lwe an ttal mt tatng tque

2 Melng an Ptn-enle Cntl f 759 T ϴ ϴ e v, v V c z ffeental tme cntant f a PID cntlle t electcal angula ptn t electcal ptn -axe tat vltage c-lnk vltage axal placement f the flywheel I. INTRODUCTION Due t ecent avance n pwe electnc an maj mpvement n mateal an beang technlgy, the FE ha becme a pmng altenatve t cnventnal chemcal battey enegy tage ytem []-[]. The FE ha attbute that make t attactve f ue n bth teetal an pace applcatn. In teetal applcatn t can be ue n hyb an electc vehcle, electc al, an hpya cane applcatn, enewable enegy applcatn, tbute geneatn f pwe mthng, pwe levelng an vltage etng [ ]-[8], an n pace applcatn t can be ue f enegy tage an atttue cntl functn [ 9]-[]. The mt/geneat the key cmpnent epnble f the thee funamental me f the FE: chage, tanby an chage. Theefe, the melng an cntl f the mt/geneat f the FE amngt the key tak f ptmzng t pefmance. Axal-flux PM machne ae ganng nceang attentn n applcatn whch eque gemetc cntant an the ue f tatnal PM machne ae nt apppate []-[5]. Due t avance n machne egn, AFPM machne can have a numbe f tnct avantage ve cnventnal aal-flux PM machne, uch a: a hghe tque, bette pwe enty an lwe ne ung peatn [6]-[9]. It ha al been hwn that ngle a-gap axal flux machne []-[] can geneate ubtantal axal fce whch have t be cunteacte by haft beang. In the machne ppe f electc vehcle n [], fel cntl ue t puce a cmpenatng axal fce t balance the axal fce between the t an the tat. Hweve, th meth eque cmplcate cntl cheme an efft n axal fce cmpenatn, whch may lmt the ange f the electmagnetc tque. Dual a-gap axal flux machne ae ue n [9], [4]-[6] whee the ttal axal fce equal t the ffeence between the tw attactve fce f the tw a-gap, an a we ange f fel cntl capablty can be acheve. Hweve, thee ytem have the cmplcatn uch a the equement f tw pwe electnc cnvete t ve the thee-phae AC cuent [5], [6] tw ffeent cnvete f the AC cuent an f the DC fel cuent ve [9]. In atn, they wee nt pecally egne f FE applcatn. Fel-ente cntl ha been utlze t cntl the mt/geneat n a FE [], [7]. In thee cheme, cntnuu t-ptn nfmatn eque. Ence Fg.. A typcal pee pfle f the FE. can be ue t etect ptn gnal. Hweve, tay ence haly atfy the we pee ange peatn, epecally n a FE. Th ue t lmtatn n tem f the mechanm an manufactung f uch tay ence. In atn, the peence f an ence peent eveal awback, uch a nceae ct an euce ytem elablty. Hence t eable t elmnate th en. In th pape, a melng an ptn-enle cntl cheme f the ual-agap AFPM machne [5] ue n FE applcatn ppe. Th AFPM machne ha tw et f thee-phae tat wnng but eque nly a ngle pwe cnvete t upply pwe t cntl bth the axal fce an the electmagnetc tque. It applcatn n a FE ealze by entatng t axal ectn vetcally an havng t uble-e t be the ce f the flywheel. Unlke the cheme ntuce n [8], the enle peatn n th pape acheve by aptng a nvel nheent pee enle tat flux beve. The ppe beve mmune t pee etmatn e, tat etance vaatn an c-ffet effect. Th allw t t elve accuate flux an pee etmatn ve a we pee ange. The glbal aympttc tablty f bth flux the beve an tat etance etmat ae guaantee by the yapunv tablty analy. The ppe ptn-enle cntl cheme n cnjunctn wth the key equement f the ptmze pefmance f the FE;.e, fat acceleatn/eceleatn f the mt/geneat f the fat chagng/chagng enegy f the FE at a euce ct an weght. mulatn tgethe wth expemental eult n a machne pttype ae peente t cnfm the effectvene f the cntl cheme. II. THE DUA-AIRAP AFPM MACHINE A FE ften egne t wk a a fat-epne enegy tage evce. A typcal pee pfle f a FE hwn n Fg., an t can change wth the la eman. Acceleatn an eceleatn f the mt/geneat n ht pe f tme eental n a FE. Theefe, hgh

3 76 Junal f Pwe Electnc, Vl., N. 5, eptembe vacuum pump uppe agap lwe agap tay ence mechancal upptng ytem placement en mechancal upptng ytem magnet uppe t tm lwe t magnet vacuum an afety chambe uppe tat & wnng lwe tat & wnng bae Fg.. Man cmpnent f the ual-agap AFPM machne n a mplfe FE. Z O pwe cnvete A B C T T F F A B C uppe tat & wnng agap (g ) flywheel z agap (g ) lwe tat & wnng Fg.. Illutatn f the ual-agap AFPM machne pncple. pefmance cntl cmbnng the mnmzatn f the axal-fce te an the fctnal le n the beang amngt the man cncen f th tuy. The man cmpnent f the ual-agap AFPM machne n a mplfe FE ae llutate n Fg.. They ae cmpe f the tat, wnng, t, m, pemanent magnet, haft, beang an mechancal upptng ytem. The TABE I PROTOTYPE DIMENION AND PARAMETER Rate pwe kva Rate cuent, m.66 A Rate vltage, m 5 V Phae etance 4.67 Ω q-axe nuctance 6.8 mh Rate fequency Hz Mment f neta.49 kg.cm Numbe f ple pa Magnet type NFeB Remanent flux enty.t Uppe tat wnng tun we tat wnng tun tat ute amete 9 mm tat nne amete 5 mm Agap length.5 mm Numbe f lt 4 Teeth wth.4 mm lt epth 8 mm Pemanent magnet length f uppe. mm t Pemanent magnet length f lwe.87 mm t machne cmpe f tw halve namely the uppe half an the lwe half, epectvely. Each uppe lwe half ha t wn tat, t, magnet an wnng but the t ae ntegate tgethe by the haft. The cmpact flywheel fme by the tw t whch ae enccle by a cabn-fbe cmpte m. The flywheel anwche n between tw k-type 4-lt tat. Each f the uppe an lwe tat cae a et f thee-phae cppe wnng whch ae the uble-laye type wth lt pe ple pe phae [9]. Rtatn f the flywheel uppte aally by the tw man beang whch can be ethe bae n cnventnal teel n avance ceamc mateal [], []. Anthe et f auxlay beang, name the mechancal upptng ytem, pve axal uppt. In peatn, the flywheel phycally cntane by th upptng ytem. The wnng cnnectn agam an the pncple f the ppe machne ae llutate n Fg.. The uppe an lwe thee-phae tat wnng ae cnnecte n ee. Hence nly ne pwe electnc cnvete neceay t peate the machne. In geneal, the pwe cnvete wk une the pule wth mulatn (PWM) cntn t enegze the thee-phae wnng. In peatn, f example, n the uppe agap, the t flux tavel axally fm the uppe t ple t the uppe tat an then back t the t. The tatng flux geneate by the cuent n the uppe tat wnng nteact wth the t flux an then

4 Melng an Ptn-enle Cntl f 76 III. MODEIN AND CONTRO OF THE DUA-AIRAP AFPM MACHINE geneate electmagnetc tque an axal fce, namely T, F, a llutate n Fg. 4. The tque an axal fce f the lwe machne half, T an F, ae eve mlaly. The net fce alng the axal ax (OZ) btane a: F F - F () The ttal electmagnetc tque wtten a: T T T magnet wth kew angle 8.7 eg. (a) (b) Fg. 4. Machne pttype: (a) 4-lt tat wth t thee-phae wnng. (b) Rt wth uface-munte pemanent magnet. q - ax φ ' q Nth φ' a uth In th AFPM machne, the ttal electmagnetc tque ue t cntl the tatn f the flywheel, whle the net axal fce ue t egulate the axal te n the beang uppt. The paamete an menn f the ual-agap AFPM machne tue n th pape ae hwn n Table I. q φ θ - ax φ q b c A - ax Fg. 5. Thee phae (a,b,c) an tatng (,q) wnng f a -ple AFPM machne. () A. Mathematcal Mel The epaate tat an t f the ual-agap AFPM machne ae hwn n Fg. 4. The pemanent magnet ae munte n the uface f a k-type t, a hwn n Fg. 4(b). Thu th machne can be analytcally analyze a a nn-alent PM machne. The analytcal appach ue f a tatnal aal flux machne emplye hee t eve the mathematcal mel f th ual-agap AFPM machne. Wth the help f the upptng ytem, the uppe an lwe agap f th machne ae ajute t be equal t each the, g g. The mel f the ual-agap AFPM machne ftly btane n the ba f the cnate axe f a -ple AFPM machne. The analy val f a geneal cae, an t then extene f a p-ple machne. The thee-phae wnng an the q-wnng layut f the -ple AFPM machne ae hwn n Fg. 5. The tatng - an q-ax wnng ae n quaatue f each the an the magnetc axe ae algne wth the - an q-ax f the t. The -ax f the t chen t be algne wth the cente lne f the magnet an the q-ax le between the magnet. The phae vltage equatn f a typcal -phae AC machne can be expee a: ABC vabc RABC () t By ung Pak tanfmatn, the -phae vaable f an AC machne can be wtten n the t efeence fame (q) a: X q [ KP ] XABC (4) A peente n the abve ectn, the machne cmpe f tw halve. Theefe the mel f ne machne half can be btane ft an the the half can then be eve n a mla manne. F ethe f the tw halve f th machne, aumng that the pemanent magnet n the t ae epeente by the magnetmtve fce f N, f f an gnng the leakage nuctance, the flux matx f the machne half can be expee a: ff M af Mbf Mcf f T M af a Mab Mac a ( f a b c) (5) M bf Mba b M ac b Mcf Mca Mcb c c whee:

5 76 Junal f Pwe Electnc, Vl., N. 5, eptembe M M M af bf cf µπ ( R R ) N a b c (6) 8P g ff f µπ ( R R ) N f 8P g f µπ ( R R) NN cθ m c θ 8P g f µπ ( R R) NN c( θ / π) m c( θ / π) (8) 8P g f µπ ( R R) NN c( θ / π) m c( θ / π) 8P g In the t-efeence fame, the lnkage flux matx n (5) tanfme nt: f m f f m (9) q q The axal fce an electmagnetc tque can be expee a: ( f q)( f q) T W c F g g µπ ( R R ) 5 ( ) () Nff NNff N q 6P g µπ ( R R ) NN f q q f q T P( ) () 6Pg The effectve a-gap between the tat an the t at the equlbum pnt ae btane a: c m (7) g Kc( g lm / µ ); g K ( g l / µ ) () The fce F an the tque T whch ae geneate by the uppe machne half can be calculate by ubttutng g g - z,, q q an N f f N f f nt the equatn, wheea the fce F an the tque T whch ae geneate by the lwe machne half can be calculate by ubttutng g g - z,, q q an N f f N f f nt the equatn. The ttal axal fce an the tatng tque can be expee a: 5 N ff NN ff N ( q ) ( g z) F F F () µπ ( R R ) 6P 5 N f f NN f f N ( q) ( g z) µπ ( R R ) N N ffq N f f q T T T 6P g z g z B. pee Cntl nce the uppe an lwe wnng ae cnnecte n ee, (4) can be tanfme nt: T µπ R R N N N ( ) f f f f q 6P g z g z (4) (5) nce z much malle than g an g, (5) mplfe nt: µπ ( R R ) N N ff N f f T q KTq (6) 6P g g The ynamc tatng equatn can be wtten a fllw: K T T e t J J whch can be tanfme nt: q (7 ) θ() ϖ() (8) KT ϖ () Iq () J (9) A pptnal ntegal (PI) cntlle ue t cntl the machne pee. C. Axal Dplacement Cntl T mplfy the mel, t aume that the aal mtn f the t tablze by aal beang. Theefe, the axal placement f the t nepenent f the aal mtn. () then can be e-wtten a: 5 N ff NN ff N ( q) µπ ( ( R ) ) R g z F 6P 5 N f f NN f f N ( q) ( g z) Defnng the fllwng elatnhp f an c : I c () () Then by lneazng (8) abut z an I, an expanng t nt the Tayl ee t the ft e tem, the axal fce equatn tanfme nt:

6 Melng an Ptn-enle Cntl f 76 whee: F F F( z, ) F.( z z).( I ) ( z, I) ( z, I) ( z, I ) z F K Kz K c () 5 N ff NN ffi N ( I q) g K F( z, I ) K 5 N f f NN f f I N ( I q) g 5 N ff NN ffi N ( I q) F ( z, I ) g K K z 5 N f f NN f f I N ( I q) g 5 NN ff NI F ( z, I ) g K K 5 NN f f NI g an µπ ( R R ) K 6P In (), the gavtatnal fce actng n the t egne t be mla t the value f K ung a epettve pceue. The axal placement z mantane at the equlbum pnt z, whch make the tem K z neglgble. The tem K c a ynamc value whch ue t cntl the levtatn fce. The ynamc equatn n the axal mtn then expee a: z c f m K Kz K t Ung the aplace tanfmatn, () becme: mz Kz K c f c () K f () () () K K z ( ) ( ) (4) m K m K A pptnal ntegal evatve (PID) cntlle ue t egulate the axal vaatn, an the tanfe functn f the PID cntlle can be wtten a: c() K K p K (5) The cntl tuctue awn a llutate n Fg. 6. The chaactetc plynmal f the ytem btane a: m KK ( KK p K) KK KK ( KK K) KK m m m p (6) u () c c () K - () u [ K ] () p m K Fg. 6. Dagam f axal placement cntl ung PID cntlle. A utable cle-lp chaactetc equatn f a th-e ytem : ( a)( ξn n) y () (7) By entfyng the chaactetc plynmal wth (7), K p, K an K ae btane. IV. POITION-ENORE CONTRO The key fact that affect the pefmance f a enle ve the accuacy f the tat flux beve. Due t the butne t paamete vaatn an tubance ejectn capablte, pee aaptve beve ae cmmnly ue. In a gtal ealzatn, pee aaptatn uually pefme a the lat tep n the etmatn pce. Hence the pee etmate affecte by cumulatve e, ne an elay. When an naccuate pee value fe back t the beve, the flux an pee etmatn gaually wen. nce pee aaptve beve eult n a cuplng between the flux an pee etmat, nn-pee aaptve beve ae eable. In the tatnay (-) efeence fame, the t flux efne a: f cθ e f nθ e (8) The tat flux lnkage gvene by: ( v R ) t ( v R ) t (9) Neglectng the lneazatn e, ffeentatng (8) an eaangng the tem eult n a mfe cuent mel f the AFPM machne. R e v t R e v ()

7 764 Junal f Pwe Electnc, Vl., N. 5, eptembe e e t () A. Obeve ynthe Defne the matx Φ a: Φ e e () It can be beve that the matx Φ appea a a cmmn tem n bth () an (). Theefe, the matx Φ can be eplace by a lng me functn that pve t etmate upn cnvegence. Φ e e () whee gn ; an ae the cuent etmatn e. Futheme, a lng me cuent beve wthut pee aaptatn can be egne a fllw. gn v v R R t (4) B. yapunv tablty Analy By ubtactng (4) fm (), the cuent etmatn e ynamc ae gven by: gn t e e (5) Defne a yapunv canate functn a: ( ) V > (6) Dffeentatng (6) bth e yel: V [ ] [ ] e (7) F tablty, V < [ ] [ ] e >. By electng a lage enugh gan, the cnvegence f the cuent beve can be guaantee. In fact, thee n uppe bun n the gan, makng t vey eay t tune f atfacty pefmance. Fg. 7. Cntl ytem agam. C. Rt pee an Ptn Etmatn Afte the lng me actn ccu, the t flux a mee ntegatn f the lng me functn wthut equng any nfmatn n the t pee a ctate by: t (8) The t ptn can then be eteve fm: e θ tan (9) Multplyng the ft an ecn w f () by an, epectvely, an eaangng the tem gve the t pee etmate: e (4) The pee gnal lw-pa fltee t emve ne. Th a cmpact yet effectve pee etmatn cheme. It can be een that the etmatn cheme epenent n the vltage nfmatn, an that t pefmance can be egae n lw pee ze pee peatn. Hweve, t well ute f th AFPM machne egne f FE applcatn. V. CONTRO YTEM Bae n the t-flux ente vect cntl, the - an q-ax cuent f the flywheel can be ecuple an cntlle epaately. Fm the tque an axal fce equatn (6) an () t can be een that tque an the fce can be cntlle nepenently f t tatn an axal levtatn.

8 Melng an Ptn-enle Cntl f 765 Pwe ccut Dplacement en Rt tat wnng Fg. 9. Cntl ytem agam f the flywheel evce. Dvng ccut Fg. 8. Expemental etup. The expemental cntl etup hwn n Fg. 9. The pee an axal placement ae upeve an cntlle by a gtal gnal pce TMF4 embee n a PACE ca tgethe wth a penal cmpute. The veall flywheel ytem blck agam hwn n Fg. 7. Infmatn n the t angle etmate fm the tat cuent an the vltage efeence. PID cntlle ae ue t cntl the pee, axal placement an t egulate the - an q-ax cuent. The tatnal angula pee * etmate an then cmpae wth the pee cmman, the pee e gnal * amplfe n the PI cntlle a the tque cmpnent cuent cmman * q n the tatnal cnate. mlaly, the e between z an ae amplfe by the PID cntlle t geneate the cuent cmman. The pace vect mulatn technque * apple t cntl a vltage uce nvete t upply the thee-phae pule wth mulatn vltage a calculate by the cntlle t fee the flywheel. VI. EXPERIMENTA REUT A. Expemental etup A machne pttype evelpe an tete. The tat yke cntucte fm lamnate n whch enlle an cmpacte a a pal. In that way, the aal flux mnmze an manly the axal path ae ue t cnuct the magnetc flux. The pemanent magnet ae mae f neymum-n-bn (NFeB5) wth a N-Cu-N catng. The expemental etup hwn n Fg. 8. The axal placement meaue by an ey-cuent type placement en an a tay ence ntalle t meaue the eal t angle f vefcatn. * z B. Expemental Reult Expement ae pefme wth a pule wth mulatn fequency f khz an a amplng tme f μ. All the ata wee captue an playe n PACE CntlDek by the penal cmpute. The AFPM machne wa epeately acceleate an eceleate fm 5 pm t, pm t mulate the chagng an chagng peatn f the FE. The axal placement efeence et at ze thughut. Bth the pee an axal placement epne ae well cntlle. They ae epcte n Fg.. Thee ae me mall vaatn n the placement ung the acceleatn an eceleatn f the machne. Th ue t the nteactn between an q n the fce equatn a eve n (). The cepnng q-axe cuent ae hwn n Fg.. The pee etmatn e n Fg. nfe that the pee etmatn pce f the beve effectve nce the etmatn e vey mall wth an aveage value f ze. The pee e, a een n Fg., ue t the lw elutn f the ntalle tay ence at,4 pule / evlutn. The pee pfle ung the tatup f th AFPM machne al btane an hwn n Fg.. The efeence, meaue an etmate value ae hwn. It can be een that the etmate fllw the efeence vey well. Th cnfm the effectvene f the enle cntl cheme apple t th AFPM machne. The mnmum pee f pm btane an hwn n the ft ubplt f Fg. 4. The pee e hwn n the ecn ubplt. It can be een that ve ytem al wk well at th mnmum pee an that the pee pefmance eteate n the lw pee egn. Hweve, peatn at uch a lw pee unealtc f a typcal FE. The mnmum peatng pee f appecable enegy tage n a FE hul be appxmately pm.

9 766 Junal f Pwe Electnc, Vl., N. 5, eptembe pee [pm] pee(pm) efeence pee meaue pee etmate pee Dplacement [mm] x Tme [ ] Fg.. Expemental eult f the ppe ptn enle AFPM ve: pee pfle, an axal placement epectvely. Cuent I [A] Cuent Iq [A] Tme [ ] Fg.. Cuent epne f the ppe ptn enle AFPM ve wth pee pfle n Fg.. Ft an ecn ubplt hw the -an q- ax cuent epectvely. pee e [pm] Tme [ ] Fg.. pee etmatn e f pee pfle n Fg Tme() Fg.. pee pfle ung tatup. pee(pm) pee e(pm) Tme() Fg. 4. Mnmum peatng pee an pee e. VII. CONCUION efeence pee meaue pee The melng an ptn-enle vect cntl f a ual-agap axal flux pemanent magnet machne ptmze f ue n flywheel enegy tage ytem applcatn peente n th pape. The machne ha tw et f thee-phae tat wnng but t nly eque a ngle pwe cnvete t multaneuly cntl bth the electmagnetc tque an the axal levtatn fce. The meth f cntllng the pee an axal placement f the machne cue. An nheent pee enle beve al ppe f pee etmatn. The ppe beve elmnate the tay ence, whch n tun euce the veall weght an ct f the ytem whle mpvng t elablty. The effectvene f the ppe cntl cheme ha been vefe by mulatn an expement n a pttype machne.

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Uen, Melng an cntl f alent-ple pemanent magnet axal-gap elf-beang mt, IEEE/AME Tan. Mechatnc, Vl. 6, N., pp , Jun.. [7] R. Caena, R. Pena,. Ahe, an J. Clae, Pwe mthng n wn geneatn ytem ung a enle vect cntlle nuctn Machne vng a flywheel, IEEE Tan. Enegy Cnve., Vl. 9, N., pp. 6-6, Ma. 4. [8] N. Tng Duy, T. Kng Jet, Z. Ch, Z. ha, an N. Han Thng, Ptn enle cntl f a nvel flywheel enegy tage ytem, n IPEC, Cnfeence Pceeng, pp. 9-98,. [9] A. K. awhney, A Cue n Electcal Machne Degn, Dhanpat Ra & n, 987. [] M. Naka,. Takaa, M. Yha, M Kkuch, T. u, an. Nakamua, Impvement f uablty f hyb ceamc ball beang n lqu hygen at mlln n (, pm), Tblgy Onlne, Vl. 5, N., pp. 6-7, Feb.. [] Q. He, H. u, Y. Zhang, J. Ye, an Q. Nu, The chaactetc f hyb ceamc ball beang f hgh-pee pnle Intenatnal Cnfeence n Mechatnc an Autmatn, (ICMA 9), pp , 9. Tng Duy Nguyen wa bn n Bnh Dnh, Vetnam. He eceve h B.Eng. an M.Eng. fm the Hchmnh-Cty Unvety f Technlgy, Vetnam, an h Ph.D fm the Nanyang Technlgcal Unvety, ngape. He cuently wth Nanyang Technlgcal Unvety, ngape, a a Ptctal Reeach Fellw. H cuent eeach nteet nclue electcal machne egn an ve, electmagnetc, an electcal enegy cnven ytem.

11 768 Junal f Pwe Electnc, Vl., N. 5, eptembe lbet F Hck Beng eceve h Dplma n Electcal an Electnc Engneeng (wth tnctn) fm INTI Cllege, ubang Jaya, Malaya, n 4. He eceve h B.. n Electcal Engneeng (wth ft-cla hn) an h Ph.D. fm the Unvety f New uth Wale, yney, Autala, n 7 an, epectvely. He cuently a Reeach Fellw at Nanyang Technlgcal Unvety, ngape. H cuent eeach nteet nclue electcal machne an ve. D. F a membe f the IEEE Inutal Electnc cety, the IEEE Pwe Electnc cety, an the IEEE Inuty Applcatn cety. H eeach nteet ae n electcal machne an ve. D. F a membe f the IEEE Inutal Electnc cety, the IEEE Pwe Electnc cety, an the IEEE Inuty Applcatn cety. an mt ve. Xnan Zhang eceve h B.Eng. fm Fuan Unvety, hangha, Chna (PRC), n 8. He wa wth the Chnee Acaemy f cence a a ptgauate tuent fm 8 t. He cuently a Ph.D. canate at Nanyang Technlgcal Unvety (NTU), ngape. H cuent eeach nteet nclue all electc hp, pwe electnc Kng-Jet Teng wa bn n ngape. He eceve h B.Eng. (Ft Cla) an M.Eng. fm the Natnal Unvety f ngape, ngape, an h Ph.D. fm Cambge Unvety, Cambge, U.K. He cuently the Hea f Pwe Engneeng an the Dect f the Cente f mat Enegy ytem at Nanyang Technlgcal Unvety, ngape. He ha actvely cnucte cue an pve techncal cnultatn f nute an nttutn n ngape an the cunte. He ha hel key avy appntment n vau gvenmental ganzatn f the ngape gvenment. He ha publhe ve a hune techncal pape, an actvely evew an et pape f maj junal an cnfeence. D. Teng a Fellw f the Cambge Cmmnwealth cety an the Cambge Phlphcal cety. He a en Membe f the Inttute f Engnee, ngape, a Cpate Membe f the Inttutn f Engneeng an Technlgy (UK), an a en Membe f the Inttute f Electcal an Electnc Engnee (UA). In 996, he wa awae the wan Pemum by the Inttutn f Electcal Engnee (UK), f h wk n gate tun-ff thyt f ue n tactn ve. He ha hel a numbe f maj appntment n pfenal cete nclung the Cha f IEEE ngape ectn n 5. He a Chatee Engnee egtee n UK. He wa awae the IEEE Th Mllennum Meal an the IEEE Regn Ten Outtanng Vluntee Awa. Dn Mahna Vlathgamuwa eceve h B.. n Electcal Engneeng fm the Unvety f Matuwa, anka, an h Ph.D. n Electcal Engneeng fm Cambge Unvety, UK, n 985 an 99, epectvely. In 99 D Vlathgamuwa jne the chl f Electcal an Electnc Engneeng, Nanyang Technlgcal Unvety, ngape, a a ectue, an he nw an Acate Pfe. H cuent eeach nteet nclue mc-g, egn f g nteface f enewable enegy ytem an pwe cnvete.