New method to suppress torque ripple of BLDCM based on Tapped-Inductor Quasi-Z-Source net

In view of the torque ripple during the operation of BLDCM, different suppression strategies were proposed in commutation and conduction interval respectively. A Tapped-Inductor Quasi-Z-Source net was added at the front of the three-phase bridge during commutation, the DC link voltage was adjusted to equal to 4 times of the back EMF with the high boost gain characteristic of this topology, the current decreasing rate of the outgoing phase was equal to the rising rate of the incoming phase to suppress the torque ripple;The PWM-ON-PWM modulation was used in conduction interval to eliminate diode freewheeling of the non-conducting phase, current fluctuation and torque ripple were well controlled. The simulation results showed that the system can effectively reduce the torque ripple both in the commutation and conduction interval.