永磁同步电机新型有效磁链固定时滑模扰动辨识策略

The vector controller of the permanent magnet synchronous motor （PMSM ） suffers poor dynamic performance when external load disturbance occurs. Therefore, a novel active flux fixed-time sliding mode load disturbance identification method for the PMSM was proposed in this paper. Firstly, based on the definition of active flux, the active flux model of the motor was analyzed, and the reduced-order active flux third-order extended state observer was constructed in combination with the extended state observer theory to reduce the dependence on the motor parameters. Then the virtual control rate and virtual control input of the observer was constructed in combination with the fixed-time sliding mode theory to realize the fixed-time convergence of the current error and improve the observation accuracy and corresponding speed when the load torque changed dynamically. Finally, the observed load torque was fed forward to the current loop controller to realize the accurate observation and compensation of the dynamically changing load torque, and further improve the dynamic performance of the control system. The proposed disturbance identification strategy was verified by numerical simulation： Compared with the traditional sliding mode load torque observer, the fixed-time sliding mode load observer proposed in this paper has a lower steady-state error and better dynamic performance; compared with the uncompensated condition, after FTSMLT O feedforward compensation is adopted, the positive speed overshoot is reduced by about 10.7%, the negative overshoot by about 14.9%, and the overshoot under sinusoidal load by about 25.0%.