Brushless DC motors (BLDC) with two-phase conduction mode generate periodic torque ripple, which affects their applications in servo systems. On basis of model predictive control (MPC), a new torque ripple reduction approach for BLDC is proposed. Combined with mathematical analysis of different operating states of BLDC, this control method can achieve constant current of the conducted phases during noncommutation and constant non-commutation current during commutation in full speed range by predicting the pulse width modulation (PWM) duty ratio, and the torque ripple minimization can be guaranteed. The simulation results present that the proposed method is able to suppress the torque ripple efficiently at low speed and high speed, and has good robustness to deviations of motor parameters.

Brushless DC motor (BLDC),model predictive control (MPC),Pulse width modulation (PWM) duty ratio,torque ripple minimization