A new method to suppress the commutation torque ripple for BLDC motor based on ZETA converter

The commutation torque ripple generated in the commutation interval is one of the main drawbacks of Brushless DC (BLDC) motor and restricts its applications. In this paper, in order to reduce the commutation torque ripple, a novel circuit topology including a zero energy thermonuclear assembly (ZETA) converter and a dc-link voltage selection circuit is proposed and investigated. Firstly, the cause of commutation is analyzed. Then the desired DC link voltage is calculated for the novel circuit topology to make the incoming and outgoing phase currents change at the same rate during commutation, and to effectively reduce the commutation torque ripple. Finally, simulation results show that the proposed topology can effectively suppress the commutation torque ripple under both low-speed and high-speed operation.