Fuzzy Speed Regulator for Induction Motor Direct Torque Control Scheme

Transcription

1 ACEEE Int. J. on Electical and Powe Engineeing, ol., No., Dec Fuzzy peed Regulato fo Induction Moto Diect Toque Contol cheme Jagadih H. Puja,. F. Kodad Reeach chola JNTU, Anantapu & Faculty Depatment of EEE, B B College of Engg. & Tech., Hubli, India jhpuja@bvb.edu Pofeo, Depatment of EEE, Auoa Engineeing College, Hydeabad, India kodadf@ediffmail.com Abtact Thi pape peent a novel deign of a contol cheme fo induction moto a a fuzzy logic application, incopoating fuzzy contol technique with diect toque contol method fo induction moto dive. The diect toque contol method ha been optimized by uing fuzzy logic contolle intead of a conventional PI contolle in the peed egulation loop of induction moto dive ytem. The peented fuzzy baed contol cheme combine the benefit of fuzzy logic contol technique along with diect toque contol technique. Compaed to the conventional PI egulato, the high quality peed egulation of induction moto can be achieved by implementing a fuzzy logic contolle a a PI-type fuzzy peed egulato which i deigned baed on the knowledge of expet without uing the mathematical model. The tability of the induction moto dive duing tanient and teady opeation i aued though the application of fuzzy peed egulato along with the diect toque contol. The popoed fuzzy peed egulated diect toque contol of induction moto dive ytem ha been validated by uing MATLAB imulink. Index Tem Fuzzy Logic Contol (FLC), Diect Toque Contol (DTC), Induction Moto (IM), pace ecto Modulation (M), witching table. I. INTRODUCTION Fuzzy logic i ecently getting inceaing emphai in dive contol application. Recent yea, fuzzy logic contol ha found many application in the pat two decade. Thi i o lagely inceaing becaue fuzzy logic contol ha the capability to contol nonlinea uncetain ytem even in the cae whee no mathematical model i available fo the contol ytem []. o, the development of highpefomance contol tategie fo AC evo ytem dive eulted in a apid evolution. To ovecome the diadvantage of vecto contol technique, in the middle of 98, a new quick epone technique fo the toque contol of induction moto wa popoed by Takahahi a diect toque contol (DTC) []. DTC povide vey quick epone with imple contol tuctue and hence, thi technique i gaining populaity in indutie []. Though, DTC ha high dynamic pefomance, it ha few dawback uch a high ipple in toque, flux, cuent and vaiation in witching fequency of the invete. The effect of flux and toque hyteei band amplitude in the induction moto dive pefomance have been analyzed in []. To impove the pefomance of conventional DTC a fuzzy logic contolle i ued along with conventional DTC [7]. The main objective of thi pape i to imulate the fuzzy peed egulato fo induction moto diect toque contol cheme to impove the peed egulation pefomance unde tanient and teady tate uncetaintie caued by vaiation in load toque which in tem eplacing PI egulato of DTC by FLC. II. INDUCTON MOTOR TATE MODEL The dynamic input and out put equation of induction moto ae fomulated a a tate model in the tato efeence fame unde the aumption of linea magnetic cicuit, equal mutual inductance and neglecting ion loe a follow; X & ( = A X ( + BU ( () Y ( t ) = C X ( t ) () Whee A i the ytem, B i the contol and C i the obevation matice. And X( i the tate, U( i input and Y( i out put vecto with element a follow; T X ( = [ i i ] () U ( t ) = δ A = M L = ; R B T δ M σl = C = L = ; R σ = & i Y ( t ) = i σ ω ( σ ) σm σm ω ( σ ) ω ( σ ) σm σm ω σl M L L ω (4) (5) (6) (7) ; σ δ = + ; σ σ ACEEE DOI:.IJEPE...

2 ACEEE Int. J. on Electical and Powe Engineeing, ol., No., Dec Whee ω epeent oto peed. R and R ae the tato and oto eitance epectively. L, L ae the tato and oto elf-inductance and M i the mutual inductance epectively. The electomagnetic toque developed by the induction moto i expeed a, T = P i i (8) 4 em ( ) Whee, and, ae epectively, the tato fluxe pojection on the (d, q) axi efeence fame. The induction moto electomagnetic toque and load toque balancing unde equilibium can be expeed a, d T em = J ω + B ω + T (9) L dt Whee J i the moment of inetia of the oto, B damping coefficient and T L i the load toque. Fom the above mathematical epeentation, we can ee that the dynamic model of an induction moto i a tongly coupled nonlinea multivaiable ytem. The contol poblem i to chooe (, ) in uch a way a to foce the moto electical angula peed and the oto flux magnitude =[ + ] / to tack given efeence value by denoted ef and ef epectively. Note that the choice of a efeence fame otating at the ame angle and i moe uitable fo the contol poblem ince in thi fame the teady tate ignal ae eem to be contant. III. DTC CHEME FOR INDUCTON MOTOR DRIE A. Woking tategy of Conventional DTC The M technique i ued to appoximate the voltage efeence vecto by employing the combination of two out of eight poible vecto geneated by the thee phae voltage ouce invete fo IM dive i a hown in Fig.. DC A B C N Inducton Moto π = co ωt () BN m CN i = whee = m co ωt + π ( + a + a ) AN BN i = to 7 CN () () Thee thee phae voltage ae applied to the thee phae induction moto employing the equation (). The thee phae bidge invete of Fig. ha eight pemiible witching tate. The witching tate and the coeponding phae to neutal voltage of iolated neutal induction moto ae ummaized in Table.I in which i off tate and i on tate indication fo the witche to. Table M Ivete witching tate AN BN CN DC / - DC / - DC / DC / DC / - DC / - DC / DC / - DC / 4 - DC / DC / DC / 5 - DC / - DC / DC / 6 DC / - DC / DC / 7 Conide, fo example tate 5 pace vecto voltage i, DC DC DC 5 = + a + a (4) A thee ae thee independent limb, thee will be eight diffeent logic tate, povide eight diffeent voltage obtained applying the vecto tanfomation decibed a: π 4π j j i = DC + e + e (5) Eight witching combination can be taken accoding to the above expeion (5). o, the patition of d-q plane in to two zeo voltage vecto and ix non-zeo voltage vecto ae a hown in Fig.. Figue. M Invete fo Induction Moto Dive The thee phae inuoidal intantaneou voltage equation of thee phae invete of Fig. ae a follow. AN = co ωt () m ACEEE DOI:.IJEPE...

3 ACEEE Int. J. on Electical and Powe Engineeing, ol., No., Dec Figue. Patition of the d-q plane in to ix angula ecto B. tato Flux and Toque Etimation The component of the cuent (I, I ) and tato voltage (, ) ae obtained by the application of the tanfomation [5] given by () and (). The component of the tato flux (, ) ae given by (8). The tato flux linkage pe phae and the electomagnetic toque etimated ae given by (9) and () epectively. I = I & I ( ) A = I B I (6) C = ( + ) & DC = DC( ) (7) t t = ( R I )dt & = ( R I )dt (8) ACEEE DOI:.IJEPE... + = (9) The angle between efeential and tato flux i given by θ = tan () T = P I I () em ( ) The tato eitance R can be aumed contant duing a lage numbe of convete witching peiod T. The voltage vecto applied to the induction moto alo emain contant ove the time peiod T. Theefoe, eolving fit equation of ytem lead to; t = ( R I )dt () t = ( ) + T () In equation (), () tand fo the initial tato flux condition. Thi equation how that when the tem RI can be neglected in high peed opeating condition of the extemity of tato flux vecto. Alo, the intantaneou flux peed i only govened by voltage vecto amplitude [] given in (). d () dt The vecto tenion applied to the induction moto emain contant duing the ampling time peiod T. Thu we can wite, the expeion fo change in tato flux ove the ampling time peiod T a, ( k + ) ( k) + T (4) ( k + ) ( k T (5) Δ ) Equation (5) implie that by applying a vecto of tenion which i co-linea in it diection, we can inceae the tato flux. Theefoe, by electing adequate voltage vecto one can inceae o deceae the tato flux amplitude and phae to obtain the equied pefomance [] [5]. C. witching Table Fomation The vecto i+ o i- ae elected to inceae the amplitude of flux, and i+ o i- to deceae it when flux i in ecto I. If o 7 i elected, then the otation of flux i topped and the toque deceae wheea the module of flux emain unchanged. Which how that the choice of the vecto tenion depend on the ign of the eo of flux i independent of it amplitude [5]. Flux F= F= ecto Table II witching table fo DTC bai Toque I II III I I T= T= T= T= T= T= Obviouly, the exit of the coecto of flux mut be a Boolean vaiable. One add a band of hyteei aound zeo to avoid unwanted commutation when the eo of flux i vey mall [] [5]. Indeed, with thi type of coecto in pite of it implicity, one can eaily contol and maintain the end of the vecto flux in a cicula ing fom. The witching table popoed by Takahahi [] i a given in Table.II. The voltage vecto witching table eceive the input ignal fom change in flux hyteei contolle, change in toque hyteei contolle and anothe ignal fom pace vecto modulation block, hence develop the appopiate contol voltage vecto witching tate fo PWM invete accoding to the Table II. D. Hyteei contolle The change in flux and change in toque ae compenated by uing two hyteei contolle a epeented in below Fig. epectively. - T em Figue. Flux and Toque Hyteee contolle epectively

4 ACEEE Int. J. on Electical and Powe Engineeing, ol., No., Dec The change in flux i compenated uing one level hyteei band a hown Fig.. But, a the dynamic toque i geneally fate than the flux, the ue of a compenato with two level hyteei band i ued in ode to adjut the change in toque and minimize the fequency witching aveage a hown in Fig. [7]. I. TRATEGY OF PROPOED FUZZY PEED FOR IM DTC CHEME REGULATOR The popoed DTC employ an induction moto model to pedict the voltage equied to achieve a deied output toque [5]. By uing only cuent and voltage meauement, it i poible to etimate the intantaneou tato flux and output toque. An induction moto model i then ued to pedict the voltage equied to dive the flux and toque to the demanded value within a fixed time peiod. Thi calculated voltage i then yntheized uing M. A. The tuctue of Fuzzy peed Regulato fo Induction Moto DTC cheme The DTC cheme of Induction Moto dive ytem include flux and toque etimato, flux and toque hyteei contolle, fuzzy logic contolle a a fuzzy peed egulato and a witching table and a thee phae PWM invete a hown in Fig.4. In addition, we need a DC bu voltage eno and two output cuent eno fo flux and toque etimation [7]. ef ef FLC T em T L Hyteei Contolle Hyteei Contolle Flu x and Toque Etimato Z - witching Table DC Encode M DC PWM Invete i d i q IM Figue 4. The tuctue of Fuzzy peed egulato fo IM Diect Toque Contol cheme B. Fuzzy Logic Contolle Concept In the eeach wok conideed in thi pape, fuzzy logic contolle i ued to coodinate between the vaiou paamete induction moto dive ytem a hown in the block diagam of the Fig.5. Thee fuzzy contolle have got a lot of advantage compaed to the the conventional PI contolle, uch a the implicity of contol, low cot, high eliability, compactne of the hadwae a fuzzy logic contolle jut make ue of fuzzy ule and the poibility to deign without knowing the exact mathematical model of the poce []. C. PI-type Fuzzy Logic Contolle a a Fuzzy peed Regulato e(k) z - ce(k) K K FLC K du(k) Figue 5. Baic tuctue PI-type Fuzzy Logic Contolle z - u(k) In the DTC cheme of M voltage ouce invete-fed induction moto dive ytem, imultaneou contol of the toque and the flux linkage wa equied. o, the efeence toque to DTC i fed fom peed loop of the IM dive a hown in Fig.5 which i egulated uing PI-type FLC hown infig.6. In which K, K and K ae nomalization facto. The input linguitic vaiable peed eo e(k), change in peed eo ce(k) and output linguitic vaiable du(k) membehip function will be divided into even fuzzy et with the linguitic value NL (negative lage), NM (negative medium), N (negative mall), ZE (zeo), P (poitive mall), PM (poitive medium), PL (poitive lage) epectively. The fuzzy logic contolle i baically an input output tatic non-linea mapping technique. The PI-type FLC contol action can be expeed a [6], du( = K e( + K ce( I P (6) Whee K P and K I ae popotional and integal gain. On integating above equation, we get u( = K e( + K e( dt P I (7) The dicete fom of equation () can be expeed a, du( k) = K e( k) + K ce( k) I P (8) Equation (8) i a PI-type FLC with non-linea gain facto. The fuzzy aociative memoy (FAM) of Mamdani ule bae model to develop the PI-type FLC a a fuzzy peed egulato which in tem eplace the PI peed egulato of conventional DTC [8] i given in Table. III. ERROR (e) du Table III FAM of FLC a a Fuzzy peed Regulato of IM CHANGE IN ERRO R (ce) NB NM N ZE P PM PB NB NB NB NB NB NM N ZE NM NB NB NB NM N ZE P N NB NB NM N ZE P PM ZE NB NM N ZE P PM PB P NM N ZE P PM PB PB PM N ZE P PM PB PB PB PB ZE P PM PB PB PB PB ACEEE DOI:.IJEPE... 4

5 ACEEE Int. J. on Electical and Powe Engineeing, ol., No., Dec ACEEE DOI:.IJEPE.... IMULATION AND REULT To veify the popoed cheme, a numeical imulation ha been caied out by uing MATLAB IMULINK. In the pefomed imulation, cetain tato flux and toque efeence ae compaed to the value calculated in the dive and eo ae ending to the hyteei compaato. The output of the flux and toque compaato ae ued in ode to detemine the appopiate voltage vecto and tato flux pace vecto. Figue 6. Conventional DTC imulated epone with PI peed egulato Figue 7. Popoed DTC imulated epone with Fuzzy peed egulato 5 ecto location ae hown in ode to validate the contol tategie a dicued above. The digital imulation tudie wee made by uing MATLAB envionment fo the ytem decibed in Fig.4. The peed egulation loop of the induction moto dive i deigned and imulated with fuzzy logic contolle. The feedback contol algoithm wee iteated until bet imulation eult wee obtained. The ytem dynamic epone obtained by imulation wee hown in Fig.5 and Fig.6 fo tato cuent, toque and peed to conclude the compaative eult of conventional DTC with PI peed egulato and popoed DTC with FLC a a fuzzy peed egulato. The DTC with FLC a a fuzzy peed egulato of IM peent the high quality pefomance compae to the conventional DTC with PI peed egulato hown in Fig.6 and Fig.7. CONCLUION The pape peent a new appoach fo peed contol of thee phae induction moto uing fuzzy logic technique. The pape develop a DTC with FLC methodology fo AC dive ytem i intended fo an efficient contol of the toque and flux without changing the moto paamete. Alo the flux and toque can be diectly contolled with the invete voltage vecto uing M technique. Two independent hyteei contolle ae ued in ode to atify the limit of the flux and toque. The popoed ytem wa analyzed, deigned and pefomance wee tudied extenively by imulation to validate the theoetical concept. The imulation eult how that the popoed DTC with FLC a a fuzzy peed egulato i upeio to conventional DTC with PI peed egulato in obutne, in tacking peciion and in peence of load ditubance becaue FLC i inheently adaptive in natue. REFERENCE [] Jagadih H. Puja,. F. Kodad imulation of Fuzzy Logic Baed Diect Toque Contolled Pemanent Magnet ynchonou Moto Dive, Poceeding of the Intenational Confeence on Atificial Intelligence- ICAI'9, ol. I, pp , July -6, 9, La ega Nevada, UA. [] Takahahi I, Naguchi T. A new quick-epone and highefficiency contol tategy of an induction moto. IEEE Tanaction on Induty Application [IN ], 986, IA-(5): [] D. Caadei, G. Gandi, G. ea, A. Tani Effecte of flux and toque hyteei band amplitude in diect toque contol of induction machine, IEEE-IECON-94, 994, [4] Jia-Qiang Yang, Jin Huang, Diect Toque Contol ytem fo Induction Moto With Fuzzy peed Pi Regulato Poceeding of the Fouth Intenational Confeence on Machine Leaning and Cybenetic, Guangzhou, 8- Augut 5. [5] R.Toufouti.Meziane,H. Benalla, Diect Toque Contol fo Induction Moto Uing Fuzzy Logic CGT Tan. on ACE, ol.6, Iue, pp. 7-4, June, 6. [6] Lee, C. C. Fuzzy Logic in Contol ytem: Fuzzy Logic Contolle, Pat I/II, IEEE Tan. ytem Man. Cybenet (99), [7] Hui-Hui Xia, han Li, Pei-Lin Wan, Ming-Fu Zhao, tudy on Fuzzy Diect Toque Contol ytem, Poceeding of the Fouth Intenational Confeence on Machine Leaning and Cybenetic, Beijing, 4-5 Augut.

6 ACEEE Int. J. on Electical and Powe Engineeing, ol., No., Dec [8] Jagadih H. Puja,. F. Kodad Digital imulation of Diect Toque Fuzzy Contol of PMM evo ytem, Intenational Jounal of Recent Tend in Engineeing- IJRTE, ol., Nov. 9 Iue, pp. 89-9, Academy Publihe, Finland. M. Jagadih. H. Puja eceived the M. Tech in Powe and Enegy ytem fom NITK uthkal, Mangaloe Univeity in the yea 999. Cuently, he i woking a an At. Pofeo in B B College of Engineeing & Technology, Hubli, Kanataka, India in the Dept. of Electical & Electonic Engg. & imultaneouly puuing hi Ph.D. in Electical & Electonic Engg. fom the petigiou Jawahalal Nehu Technological Univeity, Anatapu, Andha Padeh, India. Hi aea of inteet i oft Computing technique baed ytem. D.. F. Kodad eceived the M.Tech. degee in Enegy ytem Engg. fom JNTU, Hydeabad, India in the yea 99. He eceived hi Ph.D. degee in Electical Engg. fom JNTU, Hydeabad, India in the yea 4. Cuently, he i woking a Pofeo and Head in Auoa College of Engg., Hydeabad, Andha Padeh, India in the Dept. of Electical & Electonic Engg. He ha publihed a numbe of pape in vaiou national & intenational jounal & confeence & done a numbe of in-houe & induty poject. He i alo guiding a numbe of PhD. Hi aea of inteet i neuo-fuzzy ytem, Renewable enegy ytem, etc. ACEEE DOI:.IJEPE... 6