Controlling Torque Ripple Vibration in a Single-Phase PFC Using the Neutral Point of an IPMSM

Abstract

This paper proposes a method to reduce the torque ripple vibration of an integrated power factor correction (PFC) converter by using the zero-phase inductance of an interior permanent magnet synchronous motor (IPMSM) when the motor is not running. When an integrated PFC converter is applied to electric vehicle (EV) chargers, it is necessary to reduce the torque oscillation of the motor caused by the charging current. In an integrated PFC converter using an IPMSM, the zero-phase current and magnetomotive force harmonics of the permanent magnet cause torque vibration. In the proposed control method, the generated torque is estimated using the back EMF table, and the phase current is controlled to cancel it. The proposed method can be used to suppress torque vibration irrespective of the mechanical angle of the rotor. The effectiveness of the proposed method is experimentally verified. Using the proposed method, the torque vibration can be suppressed by up to 91.3% as compared to that in the case of the conventional control method. Furthermore, a power factor of 99.9% is achieved under a load condition of 1kW.