Direct torque PID control of switched reluctance motor based on duty ratio control technique

The flux linkage loop and torque loop in the conventional direct torque control of switched reluctance motor are all hysteresis loops, the error ripple is permitted in the hysteresis loop width,torque increases or decreases ceaselessly, so the conventional direct torque control have the problem of bigger torque ripple inevitably. This paper presents a direct torque PID control of switched reluctance motor based on duty ratio control technique.The work time of active voltage vector is the total sampling period in the conventional direct torque control, in the direct torque PID control the work time of active voltage vector is determined by duty ratio,is the part of the total sampling period.Because the torque increases or decreases along with the work time of the active voltage vector, in the proposed method the work time of the active voltage vector can just satisfy the need of the given torqure, the proposed method has the torque characteristics of smoothness and exactness.The simulation results show that the torque ripple of the proposed method decreases greatly compared to the conventional one, better than the conventional one clearly.