级联多电平变频器等效SVPWM策略研究

Equivalent SVPWM strategy for cascaded multilevel inverter

介绍了两种新型级联多电平调制策略。策略一从变频器运行工况出发,坐标化每个H桥开关状态,通过几何方式求取开关状态及其作用时间实现调制;策略二针对SVPWM的实质是一种变型SPWM,分析了SPWM谐波注入的等效SVPWM调制策略。以三相九电平级联变频器为例进行了仿真和实验,结果证明策略二更优,且比常规SVPWM更简单、易实现。

Two novel multilevel modulation strategies were introduced. The first strategy was based on the inverter＇s running condition and per H-bridge switch state was coordinated, and then the wanted voltage＇s switch state and action time was obtained by means of geometric and look-up table method. The second strategy was focused on the essence of SVPWM （space vector pulse width modulation） strategy, namely, deformation of SPWM （pulse width modulation） strategy,and the equivalent SVPWM strategy of injecting harmonic in SPWM was analyzed. Taking three-phase nine-level cascaded inverter as an example, the simulation and experiments results show that the second strategy is better and is much easy and realizable than SVPWM.