对一种基于滑模变结构控制(SMVSC)的内置式永磁同步电机(IPMSM)无位置传感器矢量控制策略进行了研究。针对SMVSC中固有的抖动问题，对其产生的机理进行了详细的分析与研究，用一种饱和函数代替符号函数进行改进，以降低符号函数的不连续性，同时将饱和函数的边界层厚度参数设置为一变量，进行自适应调节，通过调节边界层厚度函数值，减慢状态变量趋于滑模切换面的速度，以减小抖振。仿真结果表明：所研究的控制策略具有良好的动态响应和稳态响应，获得了精确的转子估算位置和估算转速，系统具有较强的鲁棒性。

A sensorless vector control strategy of interior permanent magnet synchronous motor (IPMSM) based on sliding mode variable structure control (SMVSC) is studied. Aiming at the chattering problem of SMVSC, the generation mechanism is analyzed and studied in detail, then the saturation function is used to replace the sign function to decrease the discontinuity of sign function. At the same time, the border layer thickness parameter of the saturation function is set to be a self adaptive variable, and the value of the border layer thickness is adjusted to slow the speed of state variables approaching sliding mode switching surface to decrease the chattering problem. The simulation results prove that the proposed control strategy is effective. It has excellent dynamic and static performances, the estimated position and speed have good precision，and the system has strong robustness.