Low-Pass Sliding Mode Control for Arc Motor Based on Adaptive Reaching Law

The Permanent Magnet Arc Motor (PMAM) is widely applied in large direct-drive systems due to its high efficiency and high-power density. However, during low-speed operation, the motor is not only disturbed by the cogging torque, end torque, and flux linkage harmonics of the motor itself, but also susceptible to external disturbances and high-frequency components in the control signals. To address this issue, this article proposes a sliding mode control method that combines an integral sliding mode surface with a low-pass term and adopts an adaptive reaching law. This method effectively reduces the chattering phenomenon in sliding mode control and enhances the ability to suppress medium and high-frequency components of the system. Additionally, the integration of an extended state observer for disturbance estimation and compensation further improves the robustness of the system The stability of the proposed algorithm is confirmed through discretization analysis, and experimental results validate the effectiveness of the method.