受磁路饱和与交叉耦合效应的影响，永磁辅助同步磁阻电机(PMASynRM)的dq轴电感具有不稳定性。为适应电感不稳定性并提高系统鲁棒性，采取一种基于扩展反电动势的改进型滑模观测器(SMO)无位置传感器控制算法，以估算电机的位置信息。使用超螺旋滑模观测器(ST-SMO)代替传统滑模观测器，使用Sigmoid函数代替传统sgn符号函数，提高滑模观测器系统的抗抖振能力。引入静止坐标系锁相环(PLL)提取转子位置信息。基于MATLAB/Simulink搭建改进型滑模观测器无位置传感器矢量控制模型，通过仿真验证了该算法可以快速准确地估计转子位置，具有较好的抗抖振性和动稳态性能。

For the magnetic saturation and cross coupling effect, the dq-axis inductance parameters of the permanent magnet assisted synchronous reluctance motor (PMASynRM) are unstable. In order to adapt the instability of the inductance and improve the robustness of the system, an improved algorithm of sliding mode observer (SMO) position sensorless control is proposed, which is based on the extended back electromotive force. The proposed control can estimate the position of the motor. To improve the chattering resistance ability of the system, the super twisting (ST) SMO is used to replace the conventional SMO, and the sigmoid function is used to replace the conventional sign function. The phase-locked loop (PLL) in rest frame is used to obtain the rotor position information. An improved SMO sensorless vector control simulation model is built in MATLAB/Simulink. The simulation analysis verifies that the improved algorithm can estimate the rotor position quickly and accurately, which has good chattering resistance and dynamic and static quality.