7134

466 دكتري

دكتري

قدرت

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1391

نه، 137ص.:مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمد ابراهيمي، مهدي معلم

1/8/91

مهندسي برق و كامپيوتر

ID466 دكتري

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Torque ripple minimization and dynamic performance improvement in Optimal Efficiency DTC Control of Induction MotorsAbstract Direct Torque Control DTC is known to produce quick and robust torque response forAC drives However during steady state operation the DTC produces high level of torqueripple and variable switching frequency Development of DTC for overcoming the drawbacksof classical DTC is voltage modulation application replacing look up table of the voltagevector selection The voltage modulation is based on space vector modulation SVM withconstant switching frequency Alternatively SVM method is incorporated with DTC so called DTC SVM for induction motor drives In this thesis for improvement of steady stateoperation of DTC SVM a new strategy is proposed to minimize the torque ripple ofinduction motor In optimal efficiency control of DTC SVM the induction motor will be operated withreduced flux level at light loads When the load torque is increased suddenly the referenceflux increases Consequently the stator current overshoots from its permissible value In thisthesis a new method is proposed for current limitation Another problem in light load operation is large speed drop after sudden load torqueincrease In order to improve the dynamic response in optimal efficiency DTC SVM control a new algorithm for optimum distribution of stator current components is developed andpresented in this thesis Simulation results show the consistency and good performance of the proposed methods Keywords Direct Torque Control Induction Motor Loss Minimization Space VectorModulation Torque Ripple

محمد ابراهيمي، مهدي معلم