中文摘要：

针对传统直接转矩控制中存在磁链和转矩脉动较大，以及速度传感器的使用降低了系统可靠性、增加了系统成本等问题，分析了空间电压矢量调制的实现方式。根据当前预期电压矢量获得基本电压空间矢量的优化组合，对转矩和磁链偏差进行精确补偿，同时保证逆变器开关频率恒定。基于扩展卡尔曼滤波器同时进行定子磁链和转速观测，提高了磁链观测精度，实现了表面式永磁同步电机空间电压矢量调制直接转矩控制，保持了直接转矩控制转矩响应快和系统鲁棒性强的优点，降低了磁链和转矩脉动。仿真和实验结果验证了所提方法的可行性和有效性。

英文摘要：

There are big ripples in motor drive on current and flux linkage and torque when using traditional direct torque control （DTC）. System with speed sensor has lower reliability and higher system cost. The achievement of space vector modulation （SVM） was analyzed. According to the current expected voltage vector, optimum combination of the fundamental voltage space vector was obtained in order to accurately compensate the error of stator flux and torque. Meanwhile, space voltage vector modulation ensured inverter switch frequency constant. An extended Kalman filter （EKF） was established to estimate stator flux linkage and motor speed, thus speed sensorless direct torque control for surface permanent magnet synchronous motor （SPMSM） was realized. Rapid torque response and strong robustness of direct torque control method are still maintained. Ripples on current and flux linkage and torque are dramatically reduced.The system based on EKF is robust to motor parameters variation and load disturbance. The dynamic and static system performances are dramatically improved. The experimental results verify the feasibility and effectiveness of the method.