Torque Ripple Reduction Technique in SRM for Low Speed Range by Employing Fuzzy Logic for Dynamic Controlling of TSF

In this paper, in order to reduce torque ripple for low speed range in non-commutation region, instead of exciting by a DC current, a adjustable current according to rotor position is injected. Also, to reduce torque ripple in commutation region the modified torque sharing function (TSF) method has been used. In the proposed method, TSF is modified by a feedback from the motor speed and applying it to a fuzzy controller according to speed value. In the proposed method, motor speed, torque error, and torque error derivative are used as fuzzy controller inputs, which Turn-On and overlap angles between the phases are changed as a function of motor speed. Also reference torque of adjacent phase is modified as a function of torque error and torque error derivative. In this method, TSF is modified dynamically and momentary. The exact simulation based on Matlab/Simulink for a 3-phase 6/4 SRM are carried out to verify the effectiveness of the proposed novel method for 0 to 1500rpm speed range.