Advanced Flux-weakening Strategy Based on Single Current Regulator for Permanent Magnet Synchronous Motors

Abstract

Single current regulator (SCR) control is a novel flux-weakening technology, which turned out to be more stable in high speed region compared to voltage error regulator. However, it is complicated that switching between maximum torque per ampere control and traditional SCR flux-weakening control. And to avoid switching frequently at a critical point, it is necessary to set a current hysteresis region, which leads to the current ripple. This paper proposed a novel flux-weakening method by using the saturation of q-axis current regulator. It is essentially a method of SCR. The switching process is achieved by the saturation and desaturation of the q-axis current regulator. The proposed method is not only very stable in high speed flux-weakening region, but also very simple, and it has smoother switching process and better robustness. The effectiveness of this proposed method was proved by experiments.