Rapid Torque Rising of PMSM by Directly Chasing Rotating Flux Linkage Vector

The principle of permanent magnet synchronous motor (PMSM) torque control could be seen as driving the stator flux linkage vector to chase a rotating reference by the voltage vectors. An increase in the magnitude of the stator flux linkage vector limits the ability of the voltage vector to vary the torque angle and the torque. In most control strategies, simultaneously increasing that magnitude and the torque angle slows down the PMSM torque response. In this article, a new method to quicken the PMSM torque rising is proposed. The key idea is to predict an almost static flux linkage vector as the target and find a shortcut consisting of the voltage vector sequence during torque tracking to catch up with the rotating reference rapidly. Then, the torque rising can be accelerated by first shortening the stator flux linkage vector to quickly rotate it and then lengthening it. A set of comparative experimental results are presented to confirm the validity of this method.