Research for BLDCM torque ripple suppression based on position sensorless

Brushless DC motor(BLDCM) has the problem of torque ripple due to its structural characteristics and traditional modulation mode,which limits its application range and especially in high precision servo system. A control method that combines the PWM-ON-PWM modulation mode with BUCK converter basis on position sensorless was proposed, to eliminate or suppress the torque ripple. Simulink results showed that the method can not noly completely eliminate the freewheel current of silent phase to eliminate the non-commutation torque ripple, but also decrease the commutation torque ripple in the running process of the motor.