Fault-tolerant control for PMSM based on ADRC and Fault Estimation Compensation

According to the problem of the transition process caused by control law switching and the robustness of the Four-switch Fault-tolerant Control (FSFTC) system, a new control scheme is proposed in this paper. An extended state observer is presented to estimate the impacts of transition process. Then a feedforward compensation is used to suppress the current fluctuation resulted from control law switching. To improve the robustness of FSFTC system, an Active Disturbance Rejection Controller (ADRC) strategy is used instead of the conventional PID controller, which can effectively suppress the influence of external disturbances. And an improved current vector trajectory slope method is employed for fault diagnosis and localization. Simulation results show that the proposed scheme suppresses the speed fluctuation caused by both external disturbance and control law switching effectively.