Torque Ripple Suppression of Doubly Salient Brushless DC Motors with Current Compensation Control

Due to the torque decline during the process of phase current commutation, doubly salient electro-magnetic (DSEM) motor suffers from undesirable torque ripple. In this paper, a new control method, namely phase current compensation control, is proposed to suppress the torque ripple of DSEM motor. Two control angles a and d are introduced to implement the angle position control. Meanwhile, compensation coefficient r is introduced to increase the compensation current under phase current close-loop control. The key of compensation is to obtain better utilization of inductance variation area to produce torque and then suppress the torque ripple. Both simulation and experimental results verify the validity of the proposed method for torque ripple suppression. The results show that the torque ripple can be reduced by 48.47% with the proposed control method.