Analysis and Suppression of Torque Ripple for Doubly Salient Electro-Magnetic Motor

The Doubly Salient Electro-magnetic Motor (DSEM) is subject to significant torque ripple when working with traditional standard angle control method. To weaken the effects of the torque ripple for further applications of DSEM such as wind power generation and aerospace, in-depth analysis of the ripple generation mechanism and two novel strategies of inner torque loop and torque distribution control are presented in this paper. In conclusion, simulation and comparative analysis of the two strategies are conducted with a 2kW 12/8 DSEM prototype. The simulation results demonstrate that, compared with traditional control methods, the two novel torque control strategies can effectively suppress DSEM torque ripple. elimination method to calculate the ideal current with which no torque ripple are incurred, and suppress the torque ripple of doubly-fed DSEM with the ideal current. This method is oriented toward skewed slot machines and the calculation of ideal current is relatively complicated. (18) put forward the method of torque closed loop control strategy of a novel DSPM speed control system. Compared with traditional inner current loop control strategy, smaller torque ripple and more stable speed are realized with the novel speed control system. However, (18) did not take into consideration of the influences on DSPM torque output caused by the current distortion of inner torque loop control strategy. (19) increased DSPM output torque in the commutation interval by forwarding the on-time and delaying the off-time of the power tubes. The method reduces DSPM torque ripple but gives rise to phase current distortion and is only applicable in low-speed occasions. (20) proposed the combined method of commutation control in the software as well as detailed classification of forward angles to reduce the torque ripple. But this method is comparably complex and requires large amount of calculation of the forward angles.