Sliding Mode Control with a New-Style Disturbance Observer for Low-Speed Permanent Magnet Synchronous Motor

A siding mode control (SMC) strategy with a new-style disturbance observer is proposed for the permanent magnet synchronous motor (PMSM), which has vibration problems of rotating speed and electromagnetic torque in low speed range. In the paper the mathematical model of a PMSM composed of parameter uncertainty and disturbance is established, a SMC which can effectively improve system robustness and response is designed, a novel disturbance observer to estimate the disturbance caused by the model parameter and load changes is used, the estimated value to build a feed-forward compensation added to a SMC input is employed, and finally the stability of the scheme is analyzed. Simulation results show that the algorithm has a faster response, less stabilization error compared with the traditional SMC, and the vibration is restrained effectively.