Improved direct torque control strategy of fourphase switched reluctance motor
                                                SANG Xuyang, YAN Gangfeng, WANG Yuandong, SHI Xiasheng
                                              (College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)

Abstract: In order to solve the problem of large torque ripple and rotor vibration, a direct torque control strategy of fourphase switched reluctance motor was proposed, which was based on PWM and the improved flux model. The improved flux model and switching table, combined with the characteristics of fourphase switched reluctance motor, was designed to realize the direct torque control strategy of fourphase switched reluctance motor, which solves the problem of rotor turbulence when motor start. The PWM module was introduced into the direct torque control strategy to regulate the torque more subtly, by changing the equivalent voltage. The starting performance and torque ripple suppression effect of motor before and after optimization were simulated and compared, under Matlab/Simulink environment. The results indicate that the problem of rotor vibration during startup is solved effectively meanwhile the starting torque is improved after applicating the improved flux model，and direct torque control strategy of switched reluctance motor with PWM has better torque ripple control effect.

Key words: switched reluctance motor(SRM); direct torque control(DTC); startup optimization; pulse width modulation（PWM）