A PWM technique to minimize torque ripple in BLDC motor for low-cost applications

Abstract

This paper proposes a pulse-width modulation (PWM) technique for minimizing the torque ripple in BLDC motor. To reduce the torque ripple, the commutation interval time should be firstly known. The conventional methods of torque ripple reduction require parameters and commutation interval time computation which is sensitive to parameter variation. The proposed method is robust because the commutation interval time is mainly determined by measured terminal phase voltages. It is also low-cost scheme with minimum number of devices and not sensitive to motor parameters. The purposed method primarily computes the optimal duty ratio applied during commutation intervals to minimize the torque ripple. Both simulation and experimental results are presented to validate the proposed method, comparing with the conventional method.