A BLDC motor drive with four switch three phase inverter

Currently, electrical engineers have been focused on Brushless Direct Current (BLDC) motor drives because of their efficiency, low maintenance, low inertia, high torque-weight ratio and simple control. Conventional inverter circuits for BLDC motors includes six power switches. Whereas in this paper, a BLDC drive system with four switch inverter and a voltage controlled BLDC drive is presented to reduce in losses and the total cost. Duty ratio values are modified in accordance with commutation modes in order to balance the phase voltages.