Impact of PWM and duty ratio control on voltage for Sic Fed three phase BLDC motor drive

Abstract

This paper presents an analysis of phase voltage and dc bus utilization for a three-phase Brushless DC motor (BLDC). Both pulse-amplitude (PAM) and pulse-width modulation (PWM) is employed to control the phase voltage and line current by adjusting the duty cycle. In this paper an analytical expression is derived for six-step-commutation, Bipolar PWM, H-PWM-L-ON, and PWM-ON. Through analytical expression and experimentation a comparative analysis has been performed for the aforementioned PWM techniques. Experimental results on a three-phase star-connected Sic-based BLDC drive are provided to substantiate the analysis on phase voltage, and DC bus utilization.