Chattering Reduction Using Various Switching Functions in the Sliding Mode Control Method for PMSM Drives

This paper proposes chattering reduction using various switching functions in the sliding mode control (SMC) method for permanent magnet synchronous motor (PMSM) drives. In general, a PI controller is used in PMSM control systems. However, the PI controller has limitations due to the linear control structure when dealing with nonlinearities and uncertainties, and its low robustness to parameter variations and disturbances can lead to performance degradation when operating conditions change. To overcome these limitations, the SMC method has been researched. However, the traditional SMC method uses the signum function as the switching function, and the discontinuity of the signum function causes chattering. Therefore, this paper uses various improved continuous switching functions to improve the responsiveness without chattering. Simulation and experimental results confirm that these various switching functions enhance both the responsiveness and robustness against disturbances in PMSM drives.