VECTOR CONTROL OF INDUCTION MOTOR BASED SPACE VECTOR MODULATION

Transcription

1 olume, Numer, 9 Electronics n Telecommunictions ECTOR CONTROL OF INDUCTION MOTOR BASED SPACE ECTOR MODULATION L BOURAS M KADJOUDJ Btn University, Algeri BP 6 Btn, kjouj_m@yhoofr Astrct: It is well known tht the vector control se on hysteresis regultors of inuction mchine resents less erformnce in term of current qulity witch trnslte y strong riles t stey stte wht increses the commuttion losses in the inverter For these resons, we roose new roch of FOC se on the SM technique Simultion results re shown to emonstrte the vliity of the roose methos Key wors: Inuction Motor, FOC, SM, Hysteresis I INTRODUCTION Nowys s consequence of the imortnt rogress relize in ower electronics inuction mchines riven y sttic converters hve ecome the most wiely use mchines in vrile see liction, for this resons of cost, size, reliility n efficiency With the vnces of inustril comuters, control lgorithms (FOC, DTC, roust n ttive control) cn now stisfctory e imlemente Among these techniques, fiel-oriente control hs emerge for high erformnce control of inuction mchines [] [] This control strtegy cn rovie the sme erformnces s chieve from sertely excite DC mchines, n its min ojective is, s in sertely excite DC mchines, to ineenently control the rouce torque n the flux, this is one y choosing -q sttionry reference frme with the sttor flux sce vector In the choice of the strtegy of sce vector moultion (SM), vector roch of the inverter which offers irect on with the trnsformtions use in the moern controls Thus the methos known s of sce vector moultion or SM The sce vector moultion is strtegy of reference; its rincile is the continution of the vector tension [] [] In this er, we resent simultion of n inirect fiel-oriente control for n inuction motor se on SM The imlemente system resente in this er consists of n inuction motor with its sttic inverter with technique SM, n see, n current controllers II DESCRIPTION OF THE SM ALGORITHM Sce vector moultion SM is imlemente using the irect metho n is use in the inuction motor SM is referre strtegy for high erformnce s rives ue to increse utiliztion of the c link n the cility to reuce the switching losses s comre to the hysteresis current control[8] Bse on the toology of the inverter ower stge, shown in fig there re eight ossile switching sttes for the outut line voltge sce vector, which is se on the constrint tht the inut lines cn never e shorte n the hse currents must e continuous [6]The eight ossile switching sttes re etermine form the ifferent ossile vlues of the inuction motor line to line voltges TABLE I Switching Sttes in Tow-Level Inverter n the stte c c qs c -c (/c)e j c -c (/c)e j9 -c c (/c)e j -c c (/c)e -j - c c (/c)e -j9 c - c (/c)e -j Corresoning Outut Line to Line oltge n Sttor q Comlex oltge Sce ector In ition, the inverter outut line to line voltge sce vector is esignte s [ c c ] T To hel etermine the ossile inverter outut line to line voltges, Mnuscrit receive Ferury 9, 9; revise Aril 6, 9 7

2 olume, Numer, 9 Electronics n Telecommunictions simlifie reresenttion of the inverter is shown in Fig, ech hse leg of the inuction motor must e either connecte to the ositive sie of the c link, or to the negtive sie c link The eqution relting the sttor c line to line voltges to the sttor q comlex sce vector is exresse y j j ( + c + c ) qsl l= e e The ossile switching sttes, resulting line to line voltges, n comlex voltge sce vectors re given in tle I The sttor line to mioint inuction motor q comlex sce vectors re relte to the sttor line to line q comlex sce vectors y the exression given in (), which reltes the line to line voltges of three hse Υ connecte lo to the line to mioint voltges l e qsl j qsl m= The sce vector igrm will ll of the ville inverter outut voltge vectors is shown in fig, where the six non-zero voltge vectors hve een ientifie To itionl switching vectors, which re not shown in Fig, re the zero vectors () n 7 () The reference ( vector, r, shown in Fig, hs length of ) c n n ngle of θ The quntities n θ re efine in () n (), resectively, where n re inut s shown in Fig = + θ = tn v r = c θ Once the reference vector, r, is known, it is synthesize uring ech switching erio y fining its rojection onto the nerest tow jcent switching vectors, using jcent switching losses [], [7] In the cse of this system, the switching erio, T is µs, which corresons to n inverter switching frequency, F of khz The synthesis of r in voltge sector is shown in Fig Since the uty cycle timing informtion is normlize to one, the zero vector must e use to ccount for the ifference etween ( + ) n unity, s shown in (6) r r r jy v + v = = m e + + = ref c In tow imensionl, the n uty cycles cn e etermine from chnge of sis of r from the () () () () () (6) 8 orthogonl sis to the sis efine y to jcent switching vectors which for sector re n, s shown in Fig The sis mtrix is etermine y exning the new sis vectors, [x,y], in terms of the stnr sis vectors, which is show in (7) A similr chnge of sis roceure cn e use in the remining five sectors The chnge of sis mtrices for ech sector is summrize in tle II Once,, n hve een etermine, the next ste is to comute the,, n c uty cycles The normlize,, n c uty cycles correson to the time the to switch of the corresoning hse, or c leg is turne the switching erio, when hse leg is on, the stte is n the to switch of fig is close n the ottom switch is oen The hse leg uty cycles re etermine se on the sector the reference vector is in n the switching stte of the jcent switching vector Therefore, for the reference vector in sector, the,, n c uty cycles re given s shown in (8) when the zero vector v() is use The,, n c uty cycles re given in (9) when the zero vector v7() is use Once the uty cycle times,, n c re etermine, s shown in Fig for sector for the cse when the zero vector is v7() / = / = + = = c = = + c = q q SECT Z SECT Duty Cycle Com Figure Sce vector moultion controller c (7) (8) (9)

3 olume, Numer, 9 Electronics n Telecommunictions v r v r v r v r v r re f Figure Inverter outut voltge vectors in the - sttionry frme TABLE II: Chnge of sis mtrix for ech of the six sectors Sector : 6 6 v r 6 v r commne vlue, n the lo torque is lie to the inuction motor moelle in the sttionry frme, which is common choice when the switching wveforms re simulte From the results otine, it is shown in Fig8 n 9tht the hrmonic comonents, when using hysteresis control, re roly sce roun n verge switching frequency of out khz When using SM control, hrmonic comonents re closely sce roun the switching frequency use, which f khz ws s = Is * Is Rs K + K i / / / / v r / / / / / / / / Iqs * Iqs Rs K + K i Ws?s q c c γ v r ref v r / Figure q current regultors in the synchronous reference frme c c Figure Synthesis of the reference vector in sector Phse Phse Phse c TS=TS Φ ref C ref C E w r FOC I s * I qs * q Current Regultor s θ Φ s S M Drivin g U TS / TS Figure Center se hse gting signls in sector III FOC WITH SM The out uts of the current regultors from the inuts to the sce vector moultor, shown in Fig The oututs of the current regultors, the n q uty cycles, re given in the rotting reference frme The n q uty cycles re returne to the sttionry reference frme y using rotting to sttionry reference frme trnsformtion, s shown in (7) The oututs of the reference frme trnsformtion, n n re use s the inuts to the sce vector I SIMULATION RESULTS The system simultion rrngement shown in Fig7 is use to otin the switching wve forms for SMA similr rrngement is use to test hysteresis current control The fiel-oriente controller in the sttor flux reference frme shown in Fig6, is use A see regultor hs een e to regulte the rotor see t the 9 T e *?s * I q s * Figure7 Schemtic of sic control softwre for inuction motor rive control + - T m e s K K ( + K ) +t r + t r X + t r Figure 8 Fiel-oriente controller in the sttor flux reference frme CONCLUSION In this er, we hve resente simultion of n inirect fiel-oriente control for n inuction motor using w r? sli * M I s * I q s *? s *

4 olume, Numer, 9 Electronics n Telecommunictions MATLAB/SIMULINK A simlifie sce vector moultion control scheme is resent for reuce switching losses in converter-fe rives The roose scheme reuces the switching ower losses significntly more thn the conventionl PWM se n hysteresis regultors n gives the sme erformnces, more over, s those otine with the SM technique The min vntges of the roose scheme re: Only two inverter legs re controlle in ech oertion intervl The switching losses re reuce Switching frequency is controllle Rotor see [r/s] 6 6 c- is-iqs current - Torque [N-m] 6 - Sttor flux [W] - Rotor see [r/s] c- is-iqs current Sttor flux [W] Torque [N-m] is current [A] HrmonicAmlitue [A] 6 - is current [A] 6 x Hrmonic frequency (Hz) Figure9 Simultion results FOC with hyst t r/s n N-m HrmonicAmlitue [A] - x Hrmonic frequency (Hz) x Figure Simultion results FOC with SM t r/s n n-m

5 olume, Numer, 9 Electronics n Telecommunictions APPENDIX Motor rmeters kw, /8, Hz, rm, 6/6A =; Rs=8Ω, rr=8ω, Ls=7H, Lr=7H, lm=8h J=Kgm, fr=nm/r/s; Фn=W REFERENCES [] M Kjouj, ME Benouzi, C Ghenni, DDillo, A Roust Hyri Current Control for PMSM Drives, IEEE Trns on Energy Conversion, ol 9 No 9-, [] M Kjouj, N Gole, MEH Benouzi, Direct Torque Control of PMSM Drive With Constnt Switching Frequency, SACAC 6, Dulin -7 July 6 [] F Blschke, The rincil of fiel- orienttion s lie to the new trns vector close-loo control system for rottingfiel mchines, InterntionlJjournl of Power n Energy Systems, vol, no, -, [] D Csei, G Serr n A Tni, Constnt Frequency Oertion of DTC Inuction Motor Drive for Electric ehicule in roc, ICEM 96, voliii, igo, Sin, Set, -, -9, 996 [] LBours, D Skri et M Kjouj, Anlyse et Prévision es Fréquences e Commuttion our l Commne DTC e l Mchine Asynchrone Fourth Interntionl Conference on Electricl Engineering CEE'6 Btn, Algeri7-8 Novemer 6 [6] C E Curos, Moifie sce vector moultion for zero voltge trnsition for three hse to c iirectionl converter Mster thesis in electricl engineering Blcksurg, irgini 996 [7] B H Kwn, T W Kim, A novel SM se hysteresis current controller, IEEE Trns ower electronic, vol, no, Mr 989 [8] N Celnovic, Sce vector moultion n control of multilevel converters PhD thesis in electricl engineering n comuter engineering Blcksurg, irgini