摘要：永磁电机直接转矩控制（DTC）系统中速度传感器的使用带来一系列问题，如：增大电机空间尺寸、增加成本及传感器灵敏度易受环境干扰等。对永磁同步电机SVMDTC的无速度传感器控制进行研究，设计了一种新型滑模速度观测器。该观测器引入Sigmoid函数作为滑模切换函数，并采用变滑模增益与虚拟采样相结合的方法来减小滑模抖振，在简化观测器结构的同时仍然可以保持较好的转速观测效果，并通过Lyapunov函数证明了观测器的稳定性及鲁棒性。仿真与实验结果证明了该观测器的有效性与正确性。

关键词：滑模观测器； 永磁同步电机；直接转矩控制；无速度传感器
Abstract: A series of problems were caused by using speed sensor in the DTC system of PMSM, like the increase of size of motor and cost and the sensitivity of sensor was easily interfered. A sensorless SVM-DTC of PMSM was researched and a new sliding mode observer was designed. For reducing the chattering of sliding mode, this observer adopted sigmoid function as the switching function and a method of variable sliding mode gain with virtual sampling, at the same time, had a concise structure and a good effect of speed observation. The stability and robustness of this observer were proved by a Lyapunov function. The results of simulation and experiments show the effectiveness and correctness of this observer.

Key words: sliding mode observer；PMSM；direct torque control；sensorless