Disturbance Rejection Control for Spmsm Based on Adaptive Super-Twisting SMO

The Sliding Mode Observer (SMO) is a widely used method for sensorless control of Surface-Mounted Permanent Magnet Synchronous Motors (SPMSM). However, the use of the sgn function in SMO can cause high-frequency chattering in the estimated back electromotive force (EMF). To solve this issue, this paper presents an improved SMO scheme that utilizes the Super-Twisting Algorithm (STA) to design the SMO with an adaptive sliding mode gain that adjusts according to motor speed. This Adaptive Super-Twisting Observer (ASTO) enhances estimation accuracy and effectively reduces chattering. Additionally, a Simplified Active Disturbance Rejection Control (SADRC) strategy is proposed to replace the conventional PI controller in the speed loop. By using a high-order Linear Extended State Observer (LESO) to estimate rotor position, speed, and disturbance signals, the system's performance to reject disturbances is significantly improved, decreasing the negative impacts of parameter mismatches in practical motor applications. The effectiveness of the proposed method is demonstrated through Simulink simulations.