为了提高永磁同步电机(PMSM)的控制精度与鲁棒性，并减小外界扰动对控制的影响，提出了一种新型趋近律的控制方法，解决了传统趋近律在收敛速度与滑模抖振之间存在冲突的问题。首先，在传统幂次趋近律的基础上提出设计了一种分段式的幂次趋近律，并在第二段幂次项后面添加一项线性项，可以更好地抑制抖振。然后，以负载转矩和转速为状态变量设计了一种滑模扰动观测器，并将观测结果反馈到速度控制环，进一步提高了控制系统鲁棒性。最后，通过仿真试验验证了该理论和方法的有效性与可行性。

In order to improve the robustness and control accuracy of permanent magnet synchronous motor (PMSM) and reduce the influence of external disturbance on the control, a sliding mode control method is proposed based on a new reaching law. The new reaching law solves the contradiction between sliding mode surface reaching time and the system chattering in the regular reaching law. Based on the traditional power approaching law, a piecewise power approaching law is proposed. A linear term is added after the second power term to better reduce chattering. A sliding mode disturbance observer is designed with the load torque and rotational speed as the observation objects. The observation results are fed back to the speed control loop to further improve the robustness. The simulation results verify the feasibility and effectiveness of the method.

湖南省自然科学联合基金项目（2018JJ4066）；湖南省教育厅科学研究重点项目（18A267）