Nonlinear Extended State Observer-based Sliding Mode Control Strategy of PMSM against Disturbances

This paper presents a nonlinear extended state observer-based sliding mode control strategy of Permanent magnet synchronous motor (PMSM) to address the poor performance of conventional double closed-loop PI control under tough conditions. A variable speed reaching law is proposed to balance the rapidity and robustness under the fixed parameters of the exponential reaching law. Then, a nonlinear extended observer is proposed to ensure the estimated accuracy of disturbance and rotational speed. Then, a deadbeat current prediction control is designed to replace the conventional dual PI current control to ensure efficient current loop control of PMSM. Furthermore, the stability proof of the proposed control strategy is developed. Experimental results are given to validate the effectiveness of the proposed control strategy. The proposed control approach can effectively improve speed and current control performance with tough conditions (e.g., speed and torque step-changes, periodic disturbances).