Fuzzy Sliding Mode Speed Controller Design of Induction Motor Drives

Transcription

1 Poceedings of the Intenational Confeence on Industial Engineeing and Opeations Management Istanbul, Tukey, July 3 6, Fuzzy Sliding Mode Speed Contolle Design of Induction Moto Dives F. Nacei, T. Laamayad and S. Belkacem Depatment of Electical Engineeing Batna Univesity Batna, Algeia M. Benbahim Depatment of Industial Engineeing Univesity of Batna Batna, Algeia Abstact this pape pesents a fuzzy sliding mode contolle fo an induction moto speed contolle to educe the sensitivity to paamete vaiations and load distubances, the poposed contol scheme combines a fuzzy contolle and a sliding mode contolle.the fuzzy contolles ae diven by the eo of the speed, eo of the flux and its change. The contol ule is established based on a systematic pocedue. The sliding mode contolle is designed based on a plant model. The poposed contolle is insensitive to paamete vaiations and load distubances. Keywods Sliding mode, Fuzzy Logic, Induction Moto, Fuzzy sliding Mode Speed. Intoduction Induction motos have been widely applied to speed contol because of thei high toque to Weight atio, high efficiency and easy maintenance.the field oiented contol []. Induction moto dive can be opeated like a DC moto.howeve,to develop a high pefomance field oiented contol induction moto dive,a suitable contolle must be taken into consideation., Many types of contolle have been developed in induction moto dive technology [],the sliding mode contol is one of the most impotant and inteesting development in this aea [3], Hence, the sliding mode contol is vey obust. howeve,a disadvantage of the sliding mode contol is that it equies a mathematical model which is usually difficult to obtain accuately fo nonlinea induction moto dives,in addition,it is sensitive to the extenal distubances, substantial developments in fuzzy contolles fo industial applications have been ; Made in ecent yeas, the most wothwhile popety of the fuzzy contolle is that it can be applied to contol systems without the need fo pocess model, howeve, it is difficult to a find systematic pocedue fo the fuzzy contol to guaantee system stability and to meet the pefomance specifications,the main featue of the fuzzy contolle is that it can convet, Linguistic contol ules into an automatic contol stategy,linguistic tems such as small, big, and lage may be defined as fuzzy sets, a fuzzy set is chaacteized by a membeship function, Moeove, linguistic contol ules may be used fo the specification of the contol law in a contol,poblem, linguistic contol ules ae usually obtained fom expeienced human opeatos, by incopoating linguistic contol ules and fuzzy set theoy,one can manipulate fuzziness and achieve the contol objectives. This pape poposes a fuzzy sliding mode contolle, which combines the fuzzy contolle and the sliding mode contolle,fo an induction moto speed contol educe the sensitivity to paamete vaiations and load distubances,the two fuzzy contolles ae diven by the eo (speed, toque and flux ) and its change, the establishment of the contol ule is based on a systematic pocedue, the sliding mode contolle is designed based on plant modeless using conventional methods, both compute fo induction moto dives ae pesented to 33

2 demonstate that the poposed contol scheme can educe the sensitivity to paamete vaiations and load distubances.. Indiect Field-Oiented Contol of the IM The dynamic model of thee-phase, induction moto can be expessed in the d-q synchonously otating fame as []: di ds L L. R L. m R..... m. m s R i ds Ls e iqs d. q. V ds dt. Ls L L L di qs L L L. R.. L.. i R m. R. i m.. m s e ds s qs d. V q qs dt. Ls L L L d d Lm. R R. i ds. d e. d dt L L dq L. R R m. i. qs e d. q dt L L d P. Lm f P. i. i. c qs d ds q.. T l dt L. J J J Whee is the coefficient of dispesion and is given by: Lm σ =- () LL L s, L, L m stato, oto and mutual inductances; R, R stato and oto esistances; s e, sl Slip fequency e ; Roto time constant P electical and oto angula fequency; Pole pais L ; R s () The main objective of the vecto contol of induction motos is to independently contol the toque and the flux; this is done by using a d-q otating efeence fame synchonously with the oto flux space vecto. In ideally field-oiented contol, the oto flux linkage axis is foced to align with the d-axes, and it follows that [4]: d q q (3) dt d cte Applying the esult of () and (3), namely field-oiented contol, the toque equation become analogous to the DC machine and can be descibed as follows: 3 p Lm Te iqs (4) L And the slip fequency can be given as follow: * L i m qs sl (5) 33

3 Figue : Block diagam of IFOC fo an induction moto 3. Sliding Mode Contol A Sliding Mode Contolle is a Vaiable Stuctue Contolle. Basically, a includes seveal diffeent continuous functions that can map plant state to a contol suface, and the switching among diffeent functions is detemined by plant state that is epesented by a switching function [5, 6, 7]. Without lost of geneality, conside the design of a sliding mode contolle fo the following second ode system: Ids*, Iqs* ae the inputs to the system; the following is a possible choice of the stuctue of a sliding mode contolle [8, 9]: s ksigns (6) s k. sign( s) Whee s, s ae called suface change which ae used when the system state is in the sliding mode. K, K ae a constant and it is the maximal value of the contolle output. s,s ae called switching function because the contol action switches its sign on the two sides of the switching suface s ; s. s,s Ae defined as [7, 8, and 9]: Whee s (y ef). s (/)*(y def). sign is a sign function, which is defined as: s sign s s ε sign s = s < ε sign s s ε sign s = (9) s < ε And constant facto, defines the dead aea. The contol stategy adopted hee will guaantee the system tajectoies move towad and stay on the sliding suface s, s fom any initial condition if the following condition meets: ss () ss 33 (7) (8)

4 4. Fuzzy Contolles A fuzzy contolle basically compises fou pinciple elements; fuzzification, fuzzy contol ules, fuzzy infeence engine, defuzzification, the design of the fuzzy contolle is descibed as follows: 4. fuzzification In the poposed fuzzy contolle, the system vaiables ae defined as follows: e e ; e ae change of the eo. K e ; k e ae the gain of the fuzzification. Ke ; ke ae the gain of the fuzzification. e ef ef () 4. Fuzzy infeence engine In a fuzzy infeence engine, fuzzy logic pinciples ae used to combine the fuzzy IF_THEN ules in the fuzzy contol ules. Whee idsf,iqsf calculate by a fuzzy infeence mechanism. Because the data manipulated in the fuzzy infeence mechanism is based on fuzzy set theoy, the associated fuzzy sets involved in the fuzzy contol ules ae defined as follows: NG : Negative big NG : Negative big NS : Negative small NS : Negative small EZ : zeo EZ : zeo PS : Positive small PS : Positive small PG : Positive big PG : Positive big And thei univese of discouses ae assigned to be between [-, ] fo the inputs (e and output vaiable u ). e ), and [, 3] fo the les fonctions d'appaten Figues : Membeship functions of inputs e and Δe les fonctions d'appaten Figues 3: Membeship functions of output u With fuzzy infeence mechanism, the paamete u is tansfomed to an adjustable contol and hence the sliding mode s, s can not be used to contol the system, between two values, 333

5 4.3. Fuzzy contol ules The fuzzy infeence mechanism contains twenty-five ules fo each output. The esulting fuzzy infeence ules fo the tow outputs vaiables u ae as follows: NG NS ZE PS PG NG NG NG NS NS EZ NS NG NS NS EZ PS ZE NS NS EZ PS PS PS NS EZ PS PS PG PG EZ PS PS PG PG 4.4. defuzzification The fuzzy output Whee c c 5 u can be calculated by the cente of aea defuzzification as: w 5 c c 5 wc i i w i 5 T u W 5 9 w w i i i, c tough c9 ae the cente of the membeship functions of u and 5 5 W w w w i i 5. Fuzzy Sliding Mode Contol A block diagam of the poposed fuzzy sliding mode speed contolle fo an indiect field oiented Induction moto dive is shown in (figue 4 ),which consists of the induction moto dive,the sliding mode contolle and the fuzzy contolle,in the design of the poposed contolle, the paametes of the sliding mode contolle can be detemined accoding to the design method Of a conventional sliding mode contolle,the inputs of the fuzzy contolle ae the eo (e),and,the eo change e,when the switching functions eos (s,s) ae lages, the sliding mode is contibutes contol signal (idss, iqss),and when switching functions eos(s,s) ae Small between ( s and s ), the fuzzy contolle is Contolled the system by using (idsf, iqsf). i () Figue 4: The block diagam of the poposed contolle 334

6 Let the contol inputs ids*, iqs* of the fuzzy sliding mode contolle is given as: Ids*=idsf+idss Iqs*=iqsf+iqss Whee idsf, iqsf calculate by a fuzzy infeence mechanism (FLC). Whee idss, iqss calculate by a sliding mode contolle (SMC). (3) 6. Simulation Results To pove the ightness and effectiveness of the poposed contol scheme, we apply the designed contolles to the speed contol of the induction moto. Figues 5 shows the speed esponse, toque and flux ( d, q ) of fuzzy sliding mode contolle when the machine is opeated at [ad/sec] unde no load and a nominal load distubance toque ( N.m) is suddenly applied and eliminated at.5sec, sec espectively, Figues 6 shows the speed esponse and toque and flux ( d, q ) of fuzzy sliding mode contolle when the machine is Opeated at (-ad/sec) at.3sec. The fuzzy sliding mode contolle ejects the load distubance apidly with a negligible steady state eo. Figues (7, 8, 9). The poposed contolles ae now compaed unde the same opeating conditions of the dive system. Fom the simulated esults, pefect tacking esponses and obust chaacteistics also can be obtained fo the complete fuzzy sliding-mode contol system. Figue (7, 8, 9): confim that the contolle ejects the load distubance vey apidly with no oveshoot and with negligible steady state eo. A test of obustness of the poposed contolle was also caied out by an incease in % of the oto esistance of the machine (R) (Figues 7) and of 5% of its oto inductance L (Figues 8). Othe test of obustness was effectuated by incease in % of the inetia moment of the machine (J) (Figues 9). The figues show that the poposed contolle gave satisfactoy pefomances thus judges that the contolle is obust. Toque (Nm) Speed (ad /sec) le couple électomagnétique la vitesse de otation Flux (web) leflux phq et phd en(wb) Figues 5: the esponse of the machine when it is opeated at [ad/sec] unde load N.m is suddenly applied and eliminated at.5 sec,sec espectively 335

7 Flux (web) Speed (ad /sec) Toque (Nm) le couple électomagnétique la vitesse de otation le flux phq et phd en (Wb) Figues 6: the esponse of the machine when it is opeated at- [ad/sec] unde no load is suddenly applied at.3 sec. Speed (ad /sec) la vitesse de otation w en (d/s)

8 .4. Flux (web) le flux phq et phd en (Wb) Figues 7: Simulated esults test of obustness the fuzzy sliding mode contolle (.5*R; R ; *R) Speed (ad /sec) la vitesse de otation w en (d/s) Flux (web) le flux phq et phd en (Wb) L.5*L Figues 8: Results of the test the obustness the fuzzy sliding mode contolle (.9*L ; L ; L*.5) 337

9 la vitesse de otation w en (d/s) J= J n J= *J n le flux phq et phd en (Wb) Figues 9: Simulated esults test of obustness the fuzzy sliding mode contolle (J=J n, J=*J n ) 7. Conclusion A fuzzy sliding mode contol scheme was poposed in this pape fo an induction moto speed contol to educe the sensitivity to paamete vaiations and load distubances ;in the contol scheme, the establishment of the contol ule was based on a systematic pocedue.the sliding mode contolle was designed using the conventional method. The poposed contolle is designed fo the field oiented (d,q) model of the moto,the fuzzy sliding popety of the contolle makes it moe pactical,since, in eal applications The load is not exactly known in advance and that the oto esistance may vay quite a bait; due to heating; in addition,the contolle is asymptotically stable A compute simulations and esults demonstated that the poposed contol scheme can educe the sensitivity to paametes vaiations and load distubances. Refeences [] J. P. Caon, J. P. Hautie, Modeling and Contol of Induction Machine, Technip Edition (995) (text in fench) [] L. Baghli, Contibution to Induction Machine Contol: Using Fuzzy Logic, Neual Netwoks and Genetic Algoithms, Doctoal Thesis, Heni Poincae Univesity, Januay 999 (text in fench). [3] M. A. Ouhouche, C. Volet, Simulation of a Diect Field-Oiented Contolle fo an Induction Moto Using Matlab/Simulink Softwae Package, Poc. Of IASTED Int. Conf. Modeling and Simulation (MS ), USA. [4] C.C de wit.optimisation discétisation et obsevateus. Vol. Edition Hemes Sciences Euope Ltd. Pais. [5] LI Zhen, Longya Xu, On-Line Fuzzy Tuning of Indiect Field-Oiented Induction Machine Dives, IEEE Tans. on Powe Electonics, Vol. 3 n (998). 338

10 [6] C. M. Liaw and F. J. Lin, Position Contol with Fuzzy Adaptation fo Induction Sevomoto Dive, IEE Poc. Elect. Powe. Appl., 4, pp [7] V. I. Utkin, Sliding Mode Contol Design Pinciples and Applications to Electic Dives, IEEE Tans. Ind. Elect., Vol. 4. N (993). [8] Chun_jung chen tien_chi chen fuzzy sliding mode position contolle design of induction moto deives Poceedings of the IASTED Intenationl confeence, august 4_6, 6,Honolulu, Hawaii,USA [9] H.Buhle. Réglage pa mode glissant, pesses Polytechniques Romandes; switzeland. [] H.Sholten, Logique Floue et Régulation PID.Ellips Edition Making S.A