Speed control of permanent magnet synchronous motor based on differential geometry theory and pole placement method

Permanent magnet synchronous motor (PMSM) is a nonlinear and strong coupling system. In order to improve its dynamic performance, a speed controller method is proposed in this paper. First, the PMSM is linearzed exactly by differential geometry theory. And then the speed controller is designed by linear control theory. It is proved that the PMSM with non-salient pole model in two-phase static coordinate is global state feedback exact linearizable. The way of choosing the output functions which meet exact linearization conditions is given. The PMSM system after exact linearization was completely dynamic decoupled into two subsystems. Based on this, it is simple and easy to realize that state feedback speed controller is designed by the pole placement technique in this paper. The simulation results show that the designed system has better the dynamic performance than PID control system, and the proposed method is efficient and feasible.