A Strategy of Suppressing Torque Ripple in PMSM Drive System with Open-Phase Fault

This paper proposes a method to suppress the torque ripple based on proportional integral quasi resonant (PIR) controller for the permanent magnet synchronous motor (PMSM) with three-phase four-switch (TPFS) topology. The TPFS topology, having a lower number of switches, was first presented for the possibility of reducing the inverter cost, and it became very attractive as it can be utilized in fault-tolerant control to solve the open-phase fault of the motor. However, using the TPFS topology leads the command voltages and currents to have second harmonics in the dq axis, which causes the second periodic ripple in the torque and speed. The method proposed in this paper enables to improve the disadvantages of using the TPFS topology, and to suppress the ripples of torque and speed of the motor. Simulation results clearly prove the effectiveness of the proposed method.