An Improved Sliding Mode Control Using Disturbance Torque Observer for Permanent Magnet Synchronous Motor

For the purpose of optimizing the speed control performance of the permanent magnet synchronous motor (PMSM) system, an adaptive sliding mode control (SMC) approach combining disturbance torque observer (DTO) is proposed during this paper. First, an improved sliding mode reaching law (SMRL) is introduced to reduce the sliding mode chattering. According to the choice of piecewise function term, the proposed SMRL adaptively selects the reaching velocity of the sliding mode. Then, the DTO is proposed to compensate for the effect of external disturbances. The DTO is used to produce a feed-forward signal, which is applied to the speed control loop, and the proposed SMRL is proved by Lyapunov law to ensure the stability of the whole system. Finally, the simulation and experiment results are implemented in Matlab2018a and TMS320F28335 (TI company's digital signal processor, DSP), respectively. The simulation and experimental results indicate the availability of the proposed SMC approach.