High frequency current reduction for interior permanent magnet synchronous motors

This paper proposes a new current controller with higher harmonic current reduction for interior permanent magnet synchronous motors (IPMSMs). Non-sinusoidal magnetic flux distribution on the rotor is one of the causes of the harmonic currents. The harmonic currents oscillate the d-axis and q-axis currents. The oscillation makes current control of IPMSMs unstable easily. The proposed current control system has two current controllers. One of them controls dc component in the currents to satisfy the required torque such as the conventional current controller, and another one controls high frequency components in the currents to be zero. In this paper, some experimental results are presented to demonstrate the validity of the proposed control.