Investigations into commutation torque ripple reduction in a BDCM drive using various combined PWM-square-PWM control strategies

In this paper, commutation torque ripple in a brushless dc motor is examined using simple fixed frequency PWM combined with square wave control strategies. These were easily derived from true Hall Effect sensor signals through decoding. The performances of the drive were examined from Matlab based simulation model using these techniques. It shows that the PWM-ON/ON-PWM presents better commutation torque ripple compensation over a large operating speed range. But H_PWM/L_PWM present better time response, a compromise has to be made between these strategies. An experimental testing bed was built to confirm the effectiveness of the approach used.