零序分量注入型三电平感应电动机矢量控制系统

提出一种基于三电平中点箝位(NPC)逆变器的零序分量注入型感应电动机矢量控制方案。系统中使用快速电流控制的直接转子磁链定向矢量控制模式,由于定子电流是由快速电流环控制,因此系统中不用使用定子电压方程,并且不需要解耦电路。转子磁链位置角由磁通模型计算得到。感应电动机由三电平NPC逆变器供电,三电平NPC逆变器由于开关器件的电压应力是传统两电平逆变器开关器件上电压应力的一半,所以适合用于中压调速系统。逆变器控制采用开关优化PWM算法,通过注入零序分量,不但优化功率器件的开关频率,而且可以稳定中点电位。仿真结果表明,该方法在三电平逆变器供电的感应电动机上有效地实现了矢量控制,并且具有很好的性能。

Zero-sequence component imposed three-level vector control system of induction machine

A zero-sequence component imposed vector control system of induction machine based on three-level NPC(Neutral Point Clamped) inverter is proposed,which adopts direct rotor-flux-oriented vector control mode. Since the stator current is controlled by fast current loop,the stator equations are not applied and the decoupling circuit is not necessary. The space angle of the rotor flux-linkage is calculated on flux model. The induction machine is supplied by three-level NPC inverter,which is suitable for medium-voltage drive applications because the voltage stress on its switching devices is half the voltage stress on those of conventional two-level inverter. The switching frequency optimal PWM algorithm is used for the control of three-level inverter with the zero-sequence component imposed,which not only optimizes the switching frequency of power devices,but also stabilizes the potential of neutral point. Simulation results show its effectiveness in vector control with excellent performance.