A New PWM Technique of a Two-Phase Brushless DC Motor Drive with the Switching Loss Reduction

Abstract

An improved PWM technique is presented for a two-phase brushless DC (TP-BLDC) motor fed by a two-phase eight-switch inverter. Based on traditional three-phase BLDC motors, the mathematical model of TP-BLDC motor with sinusoidal back-emfs is introduced. A two-phase BLDC motor with two hall sensors is studied for the low cost application of motor drives. To simply the drive algorithm and fast its application, the principle of current commutation for two-phase BLDC motor drives is analyzed in 180 degree conduction mode, and a further improved PWM scheme is proposed to reduce the switching loss of two-phase eight-switch inverter. Effectiveness of the proposed PWM method is verified through the experiments.