Research on torque ripple modulation for permanent brushless DC motor based on DSP

According to the large torque ripple problem which exists in brushless DC motor (BLDCM), this paper analyses the causes of commutation torque ripple and non-commutation torque ripple. The results of analysis show that the motor´s torque ripple is directly related with its phase commutation, current phase commutation, and PWM modulation. And the appropriate phase commutation time and current are calculated. Then, based on TMS320F2812 we designed the PWM modulation control strategy of BLDCM and the way of bus current control. The results of experiments show that when the motor is running between two intervals it can control torque range, and the whole running torque ripple is very small.