Segmental PWM Variable Duty Cycle Control of Switched Reluctance Motor Based on Current Chopping

Abstract

The switched reluctance motor generally adopt current chopping control at startup or at low speeds, but the problem of large torque ripple occurs in actual control. This paper analyzes the causes of torque ripple under current chopping control, and proposes a subsection PWM variable duty cycle control method based on current chopping. This control strategy adjusts the excitation voltage of the winding by changing the PWM duty cycle, and is segmented according to the inductance characteristic curve, and uses different PWM duty cycles in areas where the current rate of change is different. In this paper, a three-phase 6/20SRM simulation model is established through Matlab/Simulink, and the optimal duty cycle at different speeds is obtained through simulation, and the functional relationship between the duty cycle and the motor speed is fitted. Through simulation analysis, the control strategy in this paper has significantly reduced torque ripple at different speeds compared with traditional current chopping control, which shows that the control strategy in this paper has a significant effect on suppressing torque ripple and has good dynamic performance.