Novel Flux-Weakening Control of an IPMSM for Quasi Six-Step Operation

This paper proposes a novel flux-weakening control algorithm of an interior permanent magnet synchronous motor for ´quasi´ six-step operation. The proposed method is composed of a feed forward and a feedback path. The feedforward path consists of 1-dimensional look-up table, and the feedback is based on the difference between the reference voltage updated by current regulator and the output voltage limited by the over- modulation. Using this method, the flux-weakening and the anti- windup control can be achieved simultaneously. And also, the quasi six-step operation can be obtained. That is, the available maximum output torque in the flux-weakening region is close to that in the six-step operation while the ability of the current control is maintained. The effectiveness of this method is proved by the experimental results.