基于通用多电平SVPWM算法的三电平无速度传感器矢量控制系统

Speed Sensorless Vector Control of Induction Motors Fed by Three-Level NPC Inverter Based on a General SVPWM Algorithm

多电平变换器在高压大容量工业场合得到了广泛应用,采用合适的PWM控制策略是多电平变换器应用的关键。基于虚坐标系的空间矢量PWM算法主要包括两个部分:一是根据参考矢量计算合成基本矢量的作用时间;二是根据控制策略对零序分量进行控制选择合适的开关状态。应用该算法在一个三电平二极管钳位型逆变器上实现了异步电机的无速度传感器矢量控制,实验结果验证了其有效性和可行性。

Multilevel converters have been widely used in high-power high-voltage drive applications where an appropriate PWM control strategy is the key for the applications. In this paper,a space vector PWM （SVPWM） algorithm based on imaginary coordinate transformation is presented. The algorithm mainly includes two parts： one is the determination of the fundamental components in output according to reference vector,the other is the selection of redundant switch states to achieve a certain zero sequence component control objective. A vector control system of induction motor fed by a three-level NPC inverter based on the proposed algorithm is presented. The experimental results show the feasibility and effectiveness of the novel algorithm.