Model-Free Control of Permanent Magnet Synchronous Motor Based on Terminal Second-Order Sliding Mode

Abstract

Considering the problem that the vector speed control system of permanent magnet synchronous motor (PMSM) is susceptible to uncertainties such as load disturbances, a model-free control strategy based on terminal second-order sliding mode (TSOSM-MFC) is proposed. First, the mathematical model of PMSM is analysed and processed, and the corresponding ultra-local model of the system is summarised; then, the model-free terminal sliding mode speed controller is designed according to the ultra-local model of the system, and the chattering phenomenon in the system is suppressed by designing the second-order sliding mode reaching law (SOSMRL). Then, the sliding mode disturbance observer (SMDO) is designed to estimate the unknown part of the ultra-local model and compensate the speed loop to improve the robust performance of the system. Finally, the feasibility and effectiveness of the proposed control method are verified by simulation.