级联多电平逆变器载波移相调制法的优化研究

Optimization research on carrier phase-shifting modulation method of cascade multi-level inverter

针对传统级联高压变频器载波移相调制方法存在开关损耗大、直流电压利用率低等问题,及载波移相与矢量控制相结合的调制方法存在计算量大、计算繁琐、不易实现的问题,提出了级联多电平逆变器的优化控制方法——调制信号叠加零序分量法和两相控制法。该方法采用基于控制自由度组合的思想,通过向调制波中注入零序分量、直流分量等自由度来提高直流电压利用率、减小开关损耗。仿真结果验证了该方法的可行性。

The traditional carrier phase-shifting modulation method of cascade high-voltage inverter has the problems of large switching loss and low utilization rate of DC voltage,and modulation method based on combination of carrier phase-shifting and vector control has problems of large calculated amount,complex computation and difficult to achieve.In allusion to the problems mentioned above,an optimization control method of cascade multi-level inverter was proposed,namely zero-sequence component method of modulation signal and two-phase control method.The method uses idea of freedom degrees of combination control,and can improve DC voltage utilization rate and reduce the switching losses through injecting zero sequence component and DC component to modulation wave.The simulation result shows that the method is feasible.