Development of Wide Range High Efficiency for Electric Propulsion System

Transcription

1 EVS27 Barclona, Sain, Novmbr 17-2, 213 Dvlomnt of Wi Rang High Efficincy for Elctric Proulsion Systm un-lun Chuang, Yong-ai Lin, Shin-Hung Chang an Bo-Tsng Sung Mchanical an Systms Rsarch Laboratoris, Inustrial Tchnology Rsarch Institut, 195, Sc 4, Chung Hsing R., Chutung, Hsinchu, Taiwan, R. O. C., Abstract This stuy focuss on vlomnt of a control stratgy for a 5kW rmannt magnt synchronous motor (PMSM). Through abov-mntion control stratgy, th rformanc of PMSM can b nhanc for wi s rangs high fficincy. In this ar, vctor control is imlmnt bas on f-forwar currnt control stratgy. Thrfor, th fatur of th roos control schm is to imrov rformanc of th roortional- intgral (PI) currnt control, incluing ovrshoot, transint rsons tim an aramtrs tuning tim. Finally, th ffctivnss of th roos control stratgy for 5kW PMSM is vrifi by xrimntal rsults. ywor: PMSM, vctor control, f-forwar currnt control, roortional- intgral currnt control. 1 Introuction In rcnt yars, hom alication inustry continuously rquirs high fficincy owr lctrical machin bcaus of incrasing man of nrgy an nvironmntal issus. Th mor nrgy an nvironmntal rgulations hav bn nhanc, th mor various fforts to surss incrasing rouct cost hav bn attmt. Du to th avantags of small siz, light wight, fast rsons an high fficincy, rmannt magnt synchronous motor (PMSM) is wily us in aviation an arosac, military, inustrial an agricultural aras [1]. On th othr han, vctor control clarly rquirs instantanous control of stator currnt. Vctor control usually raliz with igital PWM controllr in rotating (-q) rfrnc fram of vctor control is to control flux an torqu of machin to riv th motor to accuratly trac th rfrnc comman valu irrsctiv of loa, machin aramtr an any xtrnal nvironmntal changs. In vctor control stator currnt is controll instantanously which rucs th torqu rils an imrovs ovrall rformanc of machin [2]. Vctor control PMSM rivs couls torqu, flux an it also maks th control quit asir. Consquntly, vctor control bcoms th cor control stratgy of PMSM. In gnral, convntional roortional-intgraliffrntial (PID)-ty controllrs hav bn wily us in inustry u to thir siml control structur, as of ign, an inxnsiv cost. Howvr, th PID-ty controllr can not rovi rfct control rformanc if th controll lant is highly nonlinar an uncrtain. Th motivation of this stuy is to ign a ral-tim control schm that osssss th volutionary caability of th f-forwar currnt control stratgy [3]. 2 Dynamic mol of PMSM Mathmatical moling of motor is rquir for simulation an analysis of riv systm. PMSM quations ar rsnt in -q rfrnc fram [4]. Th stator flux-linkag quations ar givn by: V λ = + +! (1)! t ri s ωλ EVS27 Intrnational Battry, Hybri an Ful Cll Elctric Vhicl Symosium - Abstract 1

2 λ V = ri s + ωλ! (2) t whr ω is th lctrical angular vlocity, r s is th stator rsistanc for r-has, i an i ar th -q axs stator currnts, rsctivly, V an V ar th -q axs stator voltags, rsctivly, λ an λ ar flux linkags, rsctivly. Th an q axs Flux Linkags in rotor rfrnc fram ar givn by λ = Li + L i (3) s m qr λ = Li + L i (4) s m r Th PM xcitation can b mol as a constant currnt sourc i fr. Th rotor flux is along th - axis, so th -axis rotor currnt is i fr. Th q-axis currnt in th motor is zro, bcaus thr is no flux along this axis in th rotor, by assumtion λ = L i + L i (5) m qr λ = L i + L i + L i (6) m r m fr whr L is mutual inuctanc btwn th stator m wining an rotor magnts. Abov voltag quations can b rrsnt in matrix form as givn blow # V $ # rs + sl ωl $ # i $ # ωλ f $ % V & = % + ω L rs + sl &% i & % & ( ) ( )( ) ( (7)) This is th ynamic mol of PMSM us in vctor control. Th vlo torqu motor is bing givn by 3 T = ( λi λi)! (8) 22 Us (5) an (6) into (8) can b rwrittn as 3 T = [ Lm ( ifr + ir ) i Lmiqri + ( L L ) ii ] 22 (9) Bcaus motor is us intrior rmannt magnt (IPM). So L L, iqr = ir =, Li m fr = λ f. Thrfor, accoring to (9) is xrss th follow quation [5]. 3 T = [ λ fi + ( L L) ii] (1) 22 Th mchanical torqu quation is ωr T = Jm + Bmωr + T (11) L t whr J is th momnt of inrtia of th motor, m B is th viscous cofficint of th motor, T L is m th loa torqu, T is th motor torqu, mchanical rotor s an quals to whr P is th numbr of th ols. 3 Control mthoology w is th r w 2, This rsarch rsnts th rformanc vlomnt of wi rang high fficincy for lctric roulsion systm. Th control block iagram of th roos control stratgy is ict in Fig. 1. i i i i q PI PI u _ cross u _ cross v _ ff v v v _ ff v as v bs v cs 2 3s 3r Harmonic Injction 3s 2 θ ω S Estimator v ma v mb v mc PWM Gnrator Currnt Fbacks Figur 1: Control block iagram 3.1 Major Control Dsign Obsrvr Fir Signals Powr Stag PM motor In this stuy, in orr to achiv wi s rangs high fficincy. First, thr ar two PI controllrs which achiv currnt control of -q axs. Sconly, f-forwar currnt control is introuc to comnsat th rformanc of two PI currnt control oututs of -q axs in ovrall oration rang. Thirly, th thir harmonic injction is us to ruc comutation comlxity of a motor controllr. Sinc siml comutation of PWM signals, it can rais both rats of rogram xcution an voltag utility. Th tail crition of major control ign is xhibit in th following subsctions PI controllrs Th two PI controllrs hav high stay-stat rcision; asy algorithm, goo stability an high rliability. Dfin currnt rror of -q axs, = i i, an = i i. Thrfor, two PI q currnt control oututs of -q axs can b writtn as I Vq = ( + ) (12) q S I V = ( + ) (13) S whr,, I an S is Lalac orator. I ar control gains, EVS27 Intrnational Battry, Hybri an Ful Cll Elctric Vhicl Symosium - Abstract 2

3 3.1.2 F-forwar currnt control Th f-forwar currnt control quations of -q axs via fback currnt, motor s, stator inuctanc, stator rsistanc an flux linking can b writtn as V = ri + ω L i + ωλ (14) _ ff s f V = ri ω L i (15) _ ff s Th cross coul control block iagram is ict in Fig. 2. Th cross coul control is introuc to comnsat two PI currnt control rror of -q axs in ovrall oration rang. It can b writtn as U _ cross = crossω ( i i ) (16) v v θ Park Transform 2 3s v as v bs v cs Harmonic Injction max{ abc,, } min{ abc,, } v max v harmonic v min v harmonic v ma v mb v mc PWM Gnrator PWM a PWM b PWM c Figur 3: Harmonic injction control block iagram 4 Numrical simulation an xrimntal rsults Th tail scifications of 5kW PMSM is shown in Tabl I. U _ cross = crossω ( i i ) (17) whr is cross coul gain. cross i ω cross U _ cross i iˆ iˆ ω cross U _ cross Figur 2: Cross coul control block iagram Harmonic injction In orr to ruc comutation comlxity an rais voltag utility. Thrfor, th thir harmonic injction is us in th major control systm. It is ign in Fig. 3, an can b writtn as v =.5( v + v ) (18) harmonic max min v = v v v (19) max max{ as, bs, cs} v = v v v (2) min min{ as, bs, cs} v = v + v ma as harmonic v = v + v mb bs harmonic v = v + v mc cs harmonic (21) Tabl I: Th tail scifications of 5kW PMSM 4.1. Numrical simulation In this ar all numrical simulations ar carri out using Matlab/Simulink softwar. Figur 4 shows th simulat rsults of -q axs currnt control for th PI control stratgy. As can b sn from subfigurs (a)-(b) of Figs. 4, favorabl tracking rsonss can b obtain. But occurrnc of th ovrshoot an transint rsons ar srious. Currnt (A) Currnt (A) i i (A).18 (sc) Tim(sc) i.16 (sc) (a) i 8.43 (A) Tim(sc) (b) Figur 4: Control currnt of -q axs for th PI control stratgy EVS27 Intrnational Battry, Hybri an Ful Cll Elctric Vhicl Symosium - Abstract 3

4 Figur 5 shows th simulat rsults of -q axs currnt control for roos control stratgy. As can b sn from subfigurs (a)-(b) of Figs. 5, favorabl tracking rsonss can b obtain. From th simulat rsults in subfigurs (a) (b) of Figs. 5, th rformanc of th roos control stratgy can b achiv small occurrnc of th ovrshoot an transint rsons. Accoring to currnt of q axis in Fig. 4 (a) an Fig. 5 (a), th ovrshoot has 21 (A) imrovmnts, an transint rsons has.6 (sc) imrovmnts, in numrical simulations; than th PI control stratgy. Accoring to currnt of axis in Fig. 4 (b) an Fig. 5 (b), th ovrshoot has 2 (A) imrovmnts, an transint rsons has.6 (sc) imrovmnts, in numrical simulations; than th PI control stratgy. Consquntly, th roos control stratgy is mor suitabl for lctric roulsion systm than th PI control stratgy. Figur 7: Motor controllr for this stuy i 21.89(A) 14 i 12 Currnt (A) Figur 6: 5kW PMSM for this stuy Dyna Dyna.12 (sc) 1 8 MCU MCU Tim(sc) (a) 5 Figur 8: Pictur of xrimntal st-u -5 Currnt (A) (sc) i PMSM i (A) Tim(sc) (b) Figur 5: Control currnt of -q axs for th roos control stratgy 4.2. Exrimntal rsults In orr to raliz th valu of th roos control stratgy in ractical alications, a igital signal rocssor (DSP) F288-bas control latform is us for lctric roulsion systm. Th lctric roulsion systm inclu motor an controllr. In th stuy, Fig. 6 shows th 5kW PMSM an Fig. 7 shows th motor controllr. Th ictur of th xrimntal st-u for lctric roulsion systm is ict in Fig. 8. This ar rsnts xrimntal rsults by a ynamomtr. Th xrimntal rsults inclu torqu-s curv as shown in Fig. 9, fficincy ma as shown in Fig. 1, owr an fficincy curvs as shown in Fig. 11. Comlt xrimnts guarant th stability an th rliability of th lctric roulsion systm. From Fig. 9, th xrimntal rsult of torqu-s curv confirms that th maximum outut torqu of owr moul is 21 N.m. It is vry obvious that goo fluxwakning caability la to wi s rang. W can got fin systm rformanc in 3~5 rm rang as shown in Fig. 1. Figur 9: T-N curv EVS27 Intrnational Battry, Hybri an Ful Cll Elctric Vhicl Symosium - Abstract 4

5 Acknowlgmnts Th authors woul lik to acknowlg th financial suort of Ministry of Economic Affairs (MOEA) of Taiwan, ROC, through grant numbr C353CC31. Figur 1: Efficincy ma In Fig. 11, th xrimntal rsults also vrify that th wi rang high fficincy of roos control stratgy is achiv for th lctric roulsion systm, an th systm maximum fficincy is ovr 85% whn normal rat owr is 35kW. Powr-fficincy curv also vrify that th outut owr is about 44.8 kw in 2~6 rm rang; maximum outut owr is about 73.2kW at 35 rm. Efficincy is about 9.3% in 2~6 rm rang; maximum outut fficincy is about 95.5% at 45 rm. Rfrncs [1] W. H Li, t al., Simulation rsarch on otimization of rmannt magnt synchronous motor snsorlss vctor control bas on MRAS, IEEE Prss [2] B.. Bos, Powr lctronics an variabl frquncy rivs-tchnology an alication, IEEE Prss, [3] R. J. Wai, t al, Ral-Tim PID Control Stratgy for Maglv Transortation Systm via Particl Swarm Otimization, IEEE Trans. Vol. 58, no. 2, , 211. [4] A. Mishra, t al, Moling an imlmntation of vctor control for PM Synchronous motor Driv, IEEE ICAESM, 212. [5] A. Mishra, t al, Maximum Torqu Control of IPMSM Driv with Multi-MFC, IEEE Intrnational Confrnc on Control, Automation an Systms, 21. Figur 11: Powr an fficincy curvs 5 Conclusions This ar succssfully invstigat fforwar vctor control stratgy for 5kW PMSM. Through abov-mntion control stratgy, th rformanc of PMSM can b nhanc for wi s rangs high fficincy. Th roos control stratgy rsult in th rucing of ovrshoot, transint rsons tim an aramtrs tuning tim; comaring with th PI currnt control stratgy. Thus, th roos control schm is mor suitabl for lctric roulsion systm than th PI stratgy. Th major contributions of this stuy ar summariz as follows. 1) Th succssful alication of vctor control mchanism an fforwar currnt control stratgy for th 5kW PMSM riv via a DSP consiring th ossibl xistnc of uncrtaintis. 2) Th ia of fforwar currnt control stratgy oration can b asily ali for othr control systms. Authors un-lun Chuang was born in Hsinchu, Taiwan, R. O. C., in H rciv th B.S. gr in lctrical nginring from Ming Hsin Univrsity of Scinc an Tchnology, Hsinchu, Taiwan, in 26 an th M.S. gr in lctrical nginring from Yuan Z Univrsity, Taoyuan, Taiwan, in 28. H is an nginr in Inustrial Tchnology Rsarch Institut, Hsinchu, Taiwan. His rsarch intrsts inclu control thory alications an motor srvo rivs. Dr. Yong-ai Lin rciv th B.S., M.S., an Ph.D. grs in lctrical nginring from th National Taii Univrsity of Tchnology, Taii, Taiwan. H is currntly an nginr in Mchanical an Systms Rsarch Laboratoris, Inustrial Tchnology Rsarch Institut, Hsinchu, Taiwan. His rsarch intrsts inclu th fil of filrogrammabl gat array ign an invrtr control. EVS27 Intrnational Battry, Hybri an Ful Cll Elctric Vhicl Symosium - Abstract 5

6 Dr. Shin-Hung Chang was born in Chung-Li, Taiwan, R. O. C., in H rciv th B. S. gr in lctrical nginring from National Taiwan Univrsity of Scinc an Tchnology, Taii, Taiwan, an th Ph. D. gr in lctrical nginring from Yuan Z Univrsity, Taoyuan, Taiwan, in 22 an 28, rsctivly. Sinc 28, h has bn a rsarchr an a rojct lar of EV ky comonnts in Inustrial Tchnology Rsarch Institut, Hsinchu, Taiwan. His rsarch intrsts ar intllignt, aativ, an robust control thoris an alications. Mr. Bo-Tsng Sung was born in Taoyuan, Taiwan, R. O. C., in H rciv th B. S. gr in lctronic nginring from Ta Hwa Institut of Tchnology, Hsinchu, Taiwan. H is an assistant nginr in Inustrial Tchnology Rsarch Institut, Hsinchu, Taiwan. His rsarch intrsts ar harwar ign of motor controllr, control an systm intgration. EVS27 Intrnational Battry, Hybri an Ful Cll Elctric Vhicl Symosium - Abstract 6