Commutation torque ripple reduction in brushless DC motor using modified SEPIC converter

Brushless DC Motor (BLDCM) drives, widely used in high performance applications where torque smoothness is essential, suffers from severe torque ripples. For BLDC motors, torque ripple is an important origin of acoustic noise, vibration and speed fluctuation. In this paper, a dc-dc Modified Single Ended Primary Inductor Converter (MSEPIC) and a switch selection circuit is employed in front of the inverter in order to obtain the desired commutation voltage resulting in reduced commutation torque ripple. The theoretical analysis and computer simulation, using MATLAB/ Simulink environment, are given to illustrate the proposed method and the performance is compared with conventional system. And the experimental results are also provided for verification of the BLDC drive system.