Speed Control System for Permanent Magnet Synchronous Motor Based on Improved Self-Tuning PID + NDO

In order to improve the speed control performance of the permanent magnet synchronous motor, an improved self-coupling PID with NDO (nonlinear disturbance observer) compensation control strategy is proposed. To address the problems of the traditional self-coupling PID being inflexible and making it difficult to achieve an optimal response, a four-parameter self-coupling PID control strategy is proposed. This strategy not only solves the problems of dimensional conflict and a discordant control mechanism but also expands the selection range of closed-loop poles. On the other hand, a nonlinear disturbance observer is designed to improve the system’s anti-disturbance performance. The observed disturbance is transformed into a compensating current to enhance the system’s anti-disturbance ability. Simulations and experiments demonstrate that the control strategy proposed in this paper is effective: the maximum regulation time is less than 0.03 s, the maximum dynamic speed drop is less than 5 r/min, and the maximum recovery time is less than 0.002 s.