A technique for torque ripple compensation of a low cost BLDC motor drive

This paper presents a technique to compensate the torque ripple of a BLDC motor drive, which is operated without a DC link capacitor. A simple buck converter based model for the BLDC motor drive is proposed to investigate the torque ripple. Using the model, mathematical expressions for the phase current, which indicates the torque produced by the motor, are derived. Theoretical behaviour of the motor drive, predicted from the model, is compared with Matlab/Simulink based simulations to demonstrate the validity of the compensation technique and analysis. In addition, performance of the motor drive is compared with a similar sized conventional BLDC motor drive. The proposed torque ripple compensation technique and derived mathematical expressions are expected to be useful at the design stage of low cost BLDC motor drives to achieve comparable performance.