Commutation torque ripple reduction in BLDC motor using PWM_ON_PWM mode

The paper analyzes the steady commutation process of the BLDC motor using PWM mode, confirms the commutation time to keep non-commutation phase current amplitude constant during commutation period by way of PWM in the period to implement the compensation control to eliminate commutation torque ripple under both low speed and high speed operation, investigates the effect by PWM mode on a three-phase six-state 120° turn-on BLDC motor, and presents torque ripple compensation control in PWM ON PWM mode, which can not only entirely eliminate torque ripple resulted from the current emerging in the turn-off phase during non-commutation period but also compensate torque ripple caused by the commutation current during commutation period.