Speed Control of Permanent Magnet Synchronous Motor Based on Improved Nonlinear Disturbance Observer

To improve the precision and anti-disturbance capability of the speed regulation system of permanent magnet synchronous motors, a new control approach based on a nonlinear disturbance observer is introduced. Adopting a dual-loop control strategy, the traditional PI control in the speed loop is replaced by second-order nonlinear disturbance observer control, while PI control is retained in the current loop. In order to enhance the control performance of the permanent magnet synchronous motor, the nonlinear function fal() in the disturbance observer control is replaced by the smoother gfal() function. Additionally, to improve the system's adaptability and responsiveness, fuzzy control is utilized to online adjust the crucial parameters in the nonlinear error feedback control law. Simulation results demonstrate that significantly enhance both the response rate and the capability to counteract disturbances of the motor's speed.