A Torque Ripple Reduction Drive Strategy for Permanent Magnet Brushless DC Motor with Imperfect Back Electromotive Force

This paper presents a drive strategy to reduce torque ripple of a permanent magnet Brushless DC Motor (BLDCM) with short 120? flat top Back Electromotive Force (Back-EMF). In this strategy, the phase Back-EMF is divided into four sections. Then, in each section the phase current is regulated by corresponding PWM duty ratio to compensatethe torque ripple caused by imperfect Back-EMF. A program based on this strategy has been implemented in MATLAB@Simulink. The validity of the presented method is verified by simulation results.