A Comparative Study on Predictive and ISVM Direct Torque Control Methods for a Doubly Fed Induction Machine Fed by an Indirect Matrix Converter

Transcription

1 A Cmparative Study n Predictive and ISVM Direct Trque Cntrl Methds fr a Dubly Fed Inductin Machine Fed by an Indirect Matrix Cnverter Dwnladed frm ijeee.iust.ac.ir at 1:59 IRDT n Tuesday May 8th 018 M. Aghasi*, D. A. Khaburi*, V. Faraji* and H. Behnia* Abstract: This paper presents a cmparative study n the Predictive Direct Trque Cntrl methd and the Indirect Space Vectr Mdulatin Direct Trque Cntrl methd fr a Dubly-Fed Inductin Machine (DFIM) which its rtr is fed by an Indirect Matrix Cnverter (IMC). In Cnventinal DTC technique, gd transient and steady-state perfrmances are achieved but it presents a nn cnstant switching frequency behavir and nn desirable trque ripples. Hwever, in this paper by using the prpsed methds, a fixed switching frequency is btained. In this mdel Dubly-Fed Inductin Machine is cnnected t the grid by the statr and the rtr is fed by an Indirect Matrix Cnverter. Functinally this cnverter is very similar t the Direct Matrix Cnverter, but it has separate line and lad bridges. In the inverter stage, the Predictive methd and ISVM methd are emplyed. In the rectifier stage, in rder t reduce lsses caused by snubber circuits, the rectifier furstep cmmutatin methd is emplyed. A cmparative study between the Predictive DTC and ISVM-DTC is perfrmed by simulating these cntrl systems in MATLAB/SIMULINK sftware envirnments and the btained results are presented and verified. Keywrds: Direct Trque Cntrl; Indirect Matrix Cnverter; Indirect Space Vectr Mdulatin; Predictive DTC. 1 Intrductin1 Dubly-Fed Inductin Machines (DFIMs) have windings in bth statr and rtr and bth windings are participating t pwer transfer between shaft and system. DFIMs have clear superirity fr the applicatins f large capacity and limited-range speed cntrl case due t the partially rated inverter, lwer cst and high reliability. These characteristics have enabled the dubly-fed wund rtr inductin machine t have vast applicatins in wind-driven generatin [1, ]. The Direct Trque Cntrl (DTC) methd has been intrduced in the 1980s by I. Takahashi and T. Nguchi as an alternative t Field Orientated Cntrl (FOC), with the twfld bjective f simplifying the cntrl algrithms and achieving similar r even better perfrmances [3]. Iranian Jurnal f Electrical & Electrnic Engineering, 01. Paper first received 16 Jan. 011 and in revised frm 07 May 01. * The Authrs are with the Department f Electrical Engineering, Iran University f Science and Technlgy (IUST), Tehran, Iran. s: maghasi@elec.iust.ac.ir, khaburi@iust.ac.ir, vfaraji@elec.iust.ac.ir and hbehnia@elec.iust.ac.ir, The DTC is cmmnly used with a Vltage Surce Inverter (VSI), where electrlytic capacitr is used n the dc link f the AC/DC/AC cnverter in rder t smth the dc vltage and stre the energy recvered frm the machine during regeneratin braking. Large electrlytic capacitrs in dc link cnsiderably increase the size and weight f cnverter and als decrease the lngevity f the system [4]. In recent years researches n direct frequency cnversin using Matrix Cnverters (MC) have becme ppular. Matrix cnverters have many desirable feature cmpared t the cnventinal vltage r current surce inverter such as: n need t large energy strage cmpnents, cmpact size, lnger lifetime, regeneratin capability and unitary pwer factr fr any lad [4, 5]. There are tw typical current cmmutatin methds which d nt require snubber circuits fr a PWM rectifier f AC-t-AC cnverters withut DC link cmpnents. The first methd is named rectifier zer current cmmutatin and the secnd methd is named rectifier fur-step cmmutatin [6]. Because f using rectifier fur-step cmmutatin methd in the rectifier stage, this cmmutatin prcess is firstly described in detail. 138 Iranian Jurnal f Electrical & Electrnic Engineering, Vl. 8, N., June 01

2 Dwnladed frm ijeee.iust.ac.ir at 1:59 IRDT n Tuesday May 8th 018 In this paper, als a nvel predictive DTC strategy fr Dubly-Fed Inductin Machine (DFIM) based n Indirect Matrix Cnverter is prpsed which is characterized by a simple structure, minimal trque ripple and cnstant switching frequency. The paper is rganized as fllws: in sectin II, a review f Predictive DTC fr dubly-fed inductin machines is presented; then, in sectin III, the Indirect Matrix Cnverter is intrduced. The current cmmutatin methd fr rectifier stage (rectifier furstep cmmutatin) is explained in sectin IV. In sectin V, the Predictive DTC and ISVM DTC methds, where an IMC is used t supplying the DFIM, is mdeled and explained. Simulatin results fr cmparisn between tw methds are available in sectin VI. Finally, the cnclusins are expsed in sectin VII. Predictive Direct Trque Cntrl fr a DFIM The blck diagram f the Predictive Direct Trque Cntrl is depicted in Fig. 1. In this strategy the directly cntrlled variables are the electrmagnetic trque and rtr flux amplitude which are the same variables in the cnventinal DTC methd. As it can be seen frm Fig. 1, firstly by using the DFIM equatins, the estimated values f trque, rtr flux and sectr number f the rtr flux are calculated. The estimated trque and rtr flux magnitude are then cmpared with their respective desired values and then, the resulting errrs are fed int tw tw-level hysteresis cmparatrs. The utputs f bth flux and trque cmparatrs tgether with the sectr number f rtr flux, are used as inputs f the active vectr selectin blck. Tw vltage vectrs are utputs f vectr selectin blck. The first is active vectr and in general, the secnd permitted vectr will be a zer vectr. Furthermre, in rder t have a cnstant switching frequency in this Predictive DTC cntrl technique, the switching perid h is fixed cnstant (h=1/f). At the beginning f each switching perid, the cntrl strategy calculates the ptimum active vectr, which is required t maintain trque and flux near the reference value and it can reduce their ripples. These active vectrs are btained by using a lk up table methd. The lk-up table is made up accrding t Table 1. When the utput f the cmparatr is set t 1, i.e. psitive errr, it means a psitive slpe variatin is required. On the cntrary, when the utput is set t 1, i.e. negative errr, a negative slpe variatin is needed. The prtin f active vectr in the sample perid, with h c is shwn. The typical trque and flux wavefrms, fr this cntrl strategy are represented in Fig.. Cnsidering the applied vectr and the initial cnditins at the current switching perid, the slpes f the trque and flux variatins can be calculated by using derived equatins f trque and flux [7, 8]. At each sample perid, the slpe f trque is called S1 if the active vectr is applied, and is called S if the zer vectr is applied. Similarly, S 11 and S are the slpes f the flux fr the active and the zer vectrs. During ne sample perid, the square f the square trque ripple is calculated as fllws [7, 8]: 1 hc T = ( s. t T ( k) T ). dt em ripple em em _ ref h (1) 1 h + ( s. t s. h + s. h + T ( k) T ). dt h c 1 c em em _ ref c h By deriving frm last expressin respect t the active vectr interval, h c, and equaling it t zer, the minimum ripple trque is btained. dt em ripple dh c = 0 () By slving this equatin, the ptimal switching interval, h is btained as: c.( T T ( k)) s. h em _ ref em c h = c. s s 1 (3) 3 Indirect Matrix Cnverter Indirect Matrix Cnverter as shwn in Fig. 3, is an AC/DC/AC cnverter, but bulky DC link capacitr is eliminated in it and a filter in entrance is used instead. Als, bi-directinal switches in rectifier-bridge are used instead f traditinal unidirectinal switches. Fig. 1 Predictive DTC blck diagram fr DFIM. Table 1 Predictive DTC Switching table H T 1-1 H Φ Rtr flux sectr Aghasi et al: A Cmparative Study n Predictive and ISVM Direct Trque Cntrl Methds

3 Dwnladed frm ijeee.iust.ac.ir at 1:59 IRDT n Tuesday May 8th 018 S 1 T em-ref T em (k) Ψ r (k) Ψ r-ref S 11 h c Active Vectr Fig. Steady state Trque and Flux wavefrms at mtr and generatr mdes. As it is clear frm Fig. 3, the input terminals f the cnverter are cnnected t a three phase vltage-fed system, usually the grid, while the utput terminals are cnnected t a three phase current-fed system, like an inductin mtr. Because it has cnverter cnfiguratin with tw separated stages, therefre its tplgy is mre flexible t mdify. Als, Pulse width mdulatin algrithms f cnventinal inverters can be utilized in IMC with sme mdificatins, which can greatly simplify its cntrl circuit. Furthermre cmmutatin prblem f DMC are cnsiderably reduced by using specific current cmmutatin methds in IMC [4-6]. Regarding cmmutatin strategies f IMC, tw main rules shuld be taken int accunt: 1) In rder t prevent shrt circuit in the cnverter input, the incming and utging switches shuld nt be switched n tgether at any pint in time. ) Als, in rder t prevent the ccurrence sudden vervltages and switches damage, these switches shuld nt be turned ff simultaneusly [6, 9]. Fig 3 Indirect Matrix Cnverter. h Zer Vectr T em (k+1) Ψ r (k+1) S T ensure the establishment f tw cnditin at anytime, snubber circuits are used in rectifier bridge f IMC, but since the DC link part in IMC has n smthing circuit such as electrlytic capacitrs in cnventinal VSI, the lad current must be diverted t the snubber circuits during the perid switching deadtime in rectifier-bridge. On the ther hand, the currents discharge f the snubber capacitr flws thrugh the filter capacitrs, therefre additinal lsses will be generated in cnverter. Furthermre these currents disturb t input current wavefrm [6]. Typically tw types f cmmutatins methds have been prpsed which dn t require snubber circuits fr a PWM rectifier. The first methd is named rectifier zer current cmmutatin and the secnd methd is named fur-step cmmutatin. Althugh the lsses in snubber circuits can be reduced by these methds, but a cmplicated cntrl circuit must be added t synchrnize the switching f bth the rectifier and the inverter [6]. 4 Fur-Step Cmmutatin Strategy As stated in the previus sectin, the cmmutatin prcess f matrix cnverter is mre cmplicated cmpared with traditinal AC-DC-AC cnverter due t having n natural free-wheeling paths. This cmplex cmmutatin is the main reasn that matrix cnverter culd nt be widely entered in industrial applicatin. In the past decade, imprved cmmutatin methds were suggested by researchers, which made this tplgy becming clser t the industrial applicatin. One imprtant methd which firstly presented by Nandr Burani in 1989 is fur-step cmmutatin strategy. Since this time n wards new ptimized methds based n this strategy were presented ne after anther that each had wn unique set f its advantage and disadvantages. This cmmutatin strategy t prevent shrt circuits and pen circuits uses fur steps. T execute this strategy exactly, it is necessary t btain infrmatin abut DC link current (i dc ) directin. In the ther wrds, directin f utput current and value f input vltage determine the switches sequence that use fur-step cmmutatin strategy and cmmutatin reliability depending n accuracy in current utput directin and tw input-phase vltage differences [6]. The prcess f cmmutatin is explained with Fig. 4 T AP and T BP are shwn in Fig. 4. Fr example in this case the purpse is shwing the switching between phase A and B phase A is cnnected t rectifier utput thrugh IGBT f switch S 11 and dide f switch S 1 At this pint, as it is shwn current des nt pass frm the ther transistrs and dides. It has been suppsed that cmmutatin begins frm phase A t phase B. When i dc >0 the fllwing fur-step switching sequence is: 1) turn ff S 1 ; ) turn n S 31 ; 3) turn ff S 11 ; 4) turn n S Iranian Jurnal f Electrical & Electrnic Engineering, Vl. 8, N., June 01

4 T A T B T A T B Inv & IM. Inv & IM. Dwnladed frm ijeee.iust.ac.ir at 1:59 IRDT n Tuesday May 8th 018 Fig. 4 Cmmutatin frm T AP t TBP When i dc <0, the fllwing fur-step switching sequence is: 1) turn ff S ; ) turn n S 11 3 ; 3) turn ff S 1 ; 4) turn n S Mdeling ISVM DTC Based On IMC fr DFIM In this sectin the suggested mdel f Direct Trque Cntrl based n Indirect Matrix Cnverter fr dublyfed inductin machine is presented and analyzed. The Fig. 5 shws the related blck diagram. As it s shwn, input vltages are sensed and alng with trque and flux errr and rtr flux sectr are applied t cntrl blck. Input vltage and current directin in DC link are emplyed t determinatin mde f implementatin f fur-step cmmutatin that explained in detail in last sectin. An indirect space vectr mdulatin (ISVM) is ften used fr matrix cnverters, prviding full cntrl f bth the utput vltage vectr and the instantaneus input current displacement angle. The prprtin between the tw adjacent vectrs gives the directin and the zer-vectr duty-cycle determines the magnitude f the reference vectr. 5.1 Rectifier Stage The input vltage can be calculated using the fllwing definitin: V = ( v + av + a v ) (4) i 3 a b c Assuming that the displacement angle between the fundamental cmpnent f current and the input phase vltage is θ i, therefre Phase current vectr angle can be achieved by a fictitius vectr Ix as fllws [9, 10]: I i ji x = x + y (5) in which: i = v csθ v sin θ x x i y i i = v sin θ + v csθ y x i y i The directin f I i is given by: iy Ii = arctan (7) ix Fig. 6 shws that there are six active current space vectrs each f them is related t a certain switching cnfiguratin. As presented in Fig. 7 it is pssible t btain the input current vectr by synthesize tw adjacent fixed active vectrs [10]: I = d i + d i i γ γ δ δ (8) where the relative duratin f current vectrs are: d = sin(60 θ ) δ i (9) d = sin θ γ i Fig. 5 Schematic diagram DTC based n IMC fr DFIM (6) Aghasi et al: A Cmparative Study n Predictive and ISVM Direct Trque Cntrl Methds

5 Dwnladed frm ijeee.iust.ac.ir at 1:59 IRDT n Tuesday May 8th Inverter Stage The space vectr f IMC utput line-t-line vltage V L L may be defined [9]: V = ( v + av + a v ) L L 3 AB BC CA (10) The utput line-t-line vltage vectr V 0 L L is synthesized by tw adjacent fixed active vectrs, as shwn in Fig. 8. V = d v + d v L L α α β β (11) where the relative duratin f vltage vectrs are: d = sin(60 θ ) α dβ = sinθ (1) d = 1 d d 0 α β Fig. 6 Input vltage and current vectrs Fig. 7 Synthesis f input current vectr Fig. 8 Synthesis f utput vltage vectr 5.3 Tw-Stage Matrix Cnverter T balance the input currents and the utput vltages prperly in the same switching perid, the mdulatin pattern shuld cmbine the rectificatin and inversin vectrs unifrmly, prducing the fllwing switching pattern: α γ-α δ-β γ-0. The cmbined duty-cycles f the rectificatin and inversin stages, using the previusly presented switching pattern, are btained as a crss prduct f their independent duty-cycles as shwn in Eqs. (13) [9]. d = d d = sin(60 θ ) sin( θ ) αγ α γ i (13a) dβγ = dβ dγ = sin( θ)sin( θi) (13b) d = d d = sin(60 θ ) sin(60 θ ) αδ α δ i (13c) d = d d = sin( θ ) sin(60 θ ) (13d) βδ β δ i The zer-vectr duty-cycle is determined as the cmplement f all active states cmbined. During the rest f the perid all utput phases are shrted and lad vltage is zer, i.e. zer vectr is taken: d = 1 d d d d 0 αγ αδ βγ βδ (14) The switching pattern fr an IMC is presented in Fig. 9. d β ( δ+ γ ) and d 0 γ that shwn in Fig. 9 is given by [9]: d = ( d + d ). d β( δ + γ) δ γ β (15) d = d d = d.(1 ( d + d ).( d + d )) 0γ 0 γ γ γ δ α β (16) Rectifier stage cmmutatin fr predictive DTC and ISVM-DTC methd is similar. Cmmutatin differences ccur in the inverter stage. In inverter stage, predictive DTC expressed methd in sectin II is used. S, cmmutatin pattern fr predictive DTC is as fllw [11]. 6 Simulatin Result In rder t validate the justness f the prpsed cntrl strategy, the develped cntrl system, shwn in Fig. 5, is implemented in MATLAB/SIMULINK. The machine parameters are prvided by Matlab 7.8 as fllws: 50 V statr line-line vltage, P N =15kW, f=50hz the results f trque cntrl fr bth predictive DTC and the ISVM methd are presented in Fig.11. As it can be seen, the predictive methd leads t less deviatin frm the set value f trque rather than the ISVM DTC. Fig. 1 shws the flux respnse fr these tw methds. Fig. 13 shws the flux circular trajectry fr bth predictive DTC and the ISVM methd. It is bvius that predictive methd can imprve steady and dynamic perfrmance f the system and decrease unreasnable flux ripple. Fig. 14 shws rtr current 14 Iranian Jurnal f Electrical & Electrnic Engineering, Vl. 8, N., June 01

6 Dwnladed frm ijeee.iust.ac.ir at 1:59 IRDT n Tuesday May 8th 018 Fig. 9 Switching pattern fr ISVM DTC γ h z h 0 H cγ h γ Fig. 10 Switching pattern fr predictive DTC (a) δ h z (a) (b) Fig. 13 Flux circular trajectry (a) predictive DTC (b) ISVM DTC (a) (b) Fig. 11 Trque respnse: (a) predictive DTC (b) ISVM-DTC (b) Fig. 14 Current wavefrm fr predictive methd (a) Rtr (b) Statr. (a) Fig. 15 Rtr flux sectr. (b) Fig. 1 Rtr flux respnse (a) predictive DTC (b) ISVM- DTC. and statr current respectively. Als, Fig. 15 and Fig. 16 shws rtr flux sectr and DC link vltage f IMC respectively. Aghasi et al: A Cmparative Study n Predictive and ISVM Direct Trque Cntrl Methds

7 Dwnladed frm ijeee.iust.ac.ir at 1:59 IRDT n Tuesday May 8th 018 Fig. 16 DC link vltage f IMC. Fig. 17 Rati f active vectr t zer vectr (hc/h) Table. cmparisn between predictive and ISVM In Fig. 17 rati f active vectr t zer vectr (h c /h) is shwn witch btain by Eqs. (7) and (8). The advantage f predictive methd cmpared with ISVM clearly shws in Table. As can be seen, predictive methd can imprve machine behavir significantly. 7 Cnclusin Simulatin results shw the capacity f this new predictive DTC technique with indirect matrix cnverter, t cntrl the trque and the flux f the DFIM at cnstant switching frequency. Cmpared with ISVM-DTC, ripple reductin f trque and flux in predictive DTC methd is mre. Bth methds als presents gd tracking behavir, capable f wrking at variable speed peratin cnditins fr bth mtring and generating mdes. Hwever, simulatin results shw that predictive methd is mre suitable fr use in applicatins such as wind pwer generatin. Beside the imprvements f the prpsed methd, using indirect matrix cnverter as static cnverter in this prject, the advantages f this cnverter (such as small size, near sinusidal input current and lng life-time) is als increased perfrmance f mdel. Dubly-fed inductin generatr is used extensively in wind pwer plant t generate energy. T reduce prblems f cnverter, snubber circuits were excluded frm the cnverter and Fur-step cmmutatin strategy was used instead. In rder t verify the predictive methd, a Simulatin task is prepared in SIMULINK/MATLAB sftware envirnment the btained results cnfirm the superirity f the predictive methd. Acknwledgment This wrk was supprted by Center f Excellence fr Pwer Systems Operatin & Autmatin, Department f Electrical Engineering, Iran University f Science & Technlgy. References [1] Ctter N. E. and Guillerm T. J., The CMAC and a therem f Klmgrv, Neural Netwrks, Vl. 5, N., pp. 1-8, Feb [] Liu Z., Mhammed O. A. and Liu S., A Nvel Direct Trque Cntrl f Dubly-Fed Inductin Generatr Used fr Variable Speed Wind Pwer Generatin, IEEE Pwer Engineering Sciety General Meeting, pp. 1-6, 007. [3] Mhammed O. A., Liu Z. and Liu S., Statr pwer factr adjustable direct trque cntrl f dubly-fed inductin machines, IEEE Internatinal Cnference n Electric Machines and Drives, pp , 005. [4] Takahashi I. and Nguchi T., A new quickrespnse and high efficiency cntrl strategy f an inductin mtr, IEEE Trans. Ind. Appl., Vl. IA-, N. 5, pp , Sep./Oct [5] Wheeler P. W., Rdriguez J., Clare J. C., Empringham L. and Weinstein A., Matrix cnverters: a technlgy review, IEEE Transactins n Industrial Electrnics, Vl. 49, Issue, pp , Apr 00. [6] Wei L. and Lip T. A., A nvel matrix cnverter tplgy with simple cmmutatin, Industry Applicatins Cnference, Vl. 3, pp , 001. [7] He M. X., Jun T. G., Ian W. X., Li F. Y., Xia Z. and Fei H. Y., Research n Imprved Fur-step Cmmutatin Strategy f Matrix Cnverter Based n Tw Line Vltage Synthesis Secnd Internatinal Cnference n Innvative Cmputing, Infrmatin and Cntrl, ICICIC 07, pp , 007. [8] Abad G., Rdriguez M. A. and Pza J., Tw- Level VSC Based Predictive Direct Trque Cntrl f the Dubly Fed Inductin Machine With Reduced Trque and Flux Ripples at Lw Cnstant Switching Frequency, IEEE Transactins n Pwer Electrnics, Vl. 3, Issue 3, pp , 008. [9] Abad G., Rdriguez M. A. and Pza J., Predictive Direct Trque Cntrl f the Dubly Fed Inductin Machine with Reduced Trque and Flux Ripples at Lw Cnstant Switching Frequency, IEEE Industrial Electrnics, IECON 006, pp [10] Iimri K., Shinhara K. and Yamamt K., A study f dead-time f PWM rectifier f vltage- 144 Iranian Jurnal f Electrical & Electrnic Engineering, Vl. 8, N., June 01

8 Dwnladed frm ijeee.iust.ac.ir at 1:59 IRDT n Tuesday May 8th 018 surce inverter withut DC link cmpnents and its perating characteristics f inductin mtr, Industry Applicatins Cnference, Vl. 3, pp , 004. [11] Chen X. and Kazerani M., A New Direct Trque Cntrl Strategy fr Inductin Machine Based n Indirect Matrix Cnverter, IEEE Internatinal Sympsium n Industrial Electrnics, Vl. 3, pp , 006. [1] Aghasi M., Faraji V., Khaburi D. A. and Kalantar M., Direct Pwer Cntrl fr Dubly-Fed Inductin Generatr Using Indirect Matrix Cnverters, 5th Internatinal Pwer System Cnference, Nv 010. [13] Faraji V., Aghasi M., Khaburi D. A. and Ghrbani M. J., A Mdified DTC fr Inductin Mtr Drive System Fed by Indirect Matrix Cnverter Using Active Learning Methd, nd Pwer Electrnic and Drive Systems and Technlgies Cnf., Feb Majid Aghasi was brn in 1985 in Tehran, Iran. He received B.Sc. in Electrnics Engineering and M.Sc. in Electrical Engineering frm Islamic Azad University Suth Tehran Branch and Iran University f Science & Technlgy (IUST), Tehran, Iran, 008 and 011 respectively. Since 010 he has taught as a lecturer at Islamic Azad University (IAU), Khmein Branch, Iran. Als, he is a member f Yung Researchers Club, Khmein Branch, Islamic Azad University, Khmein, Iran. His research interests are Pwer Electrnics. Davd Arab Khaburi was brn in He has received B.Sc. in 1990 frm Sharif University f Technlgy in Electrnic Engineering and M.Sc. and Ph.D. frm ENSEM INPEL, Nancy, France in 1994 and 1998, respectively. Since 000 he has been as a faculty member in Electrical Engineering Department f Iran University f Science & Technlgy (IUST). Vahid Faraji was brn in 1986 in Khmein, Iran. He has received B.Sc. in electrical engineering frm Shahed University and M.Sc. frm Iran University f Science & Technlgy (IUST), Tehran, Iran, in 008 and 011, respectively. Since 011 he has been as a faculty member in Electrical Engineering Department f Islamic Azad University (IAU), Khmein Branch, Iran. Als, he is a member f Yung Researchers Club, Khmein Branch, Islamic Azad University, Khmein, Iran. His research interests are Mtr Cntrl & Pwer Quality. Hamid Behnia was brn in 1984 in Tehran, Iran. He received B.Sc. in Electrnics Engineering and M.Sc. in Electrical Engineering frm Yazd University and Iran University f Science & Technlgy (IUST), Tehran, Iran, 008 and 011 respectively. Since 010 he has taught as a lecturer at Islamic Azad University (IAU), Khmein Branch, Iran. Als, he is a member f Yung Researchers Club, Khmein Branch, Islamic Azad University, Khmein, Iran. His research interests are Pwer Electrnics and renewable energy. Aghasi et al: A Cmparative Study n Predictive and ISVM Direct Trque Cntrl Methds