级联五开关H桥多电平逆变器功率均衡控制方法

摘要

为了提高逆变器的电压和功率等级,提出了一种级联五开关H桥多电平逆变器拓扑结构的功率均衡控制方法.该方法采用了同相交错层叠锯齿载波移相调制,综合了同相层叠锯齿载波调制良好的消谐特性以及载波移相调制各个单元功率分配均衡的优点,使级联五开关H桥多电平逆变器拓扑结构中各个功率单元不仅可以输出五电平,保持良好的消谐特性,而且可以在一个输出周期内实现功率均衡.以3个功率单元为例,进行了仿真实验.实验结果验证了该拓扑结构及其控制方法的可行性与优越性.%A power balance control scheme of cascaded multilevel inverter with five switches for each H-bridge unit is proposed in this paper to improve the voltage and power levels of the inverter. Phase disposition modulation and phase-shift modulation are adopted,which has advantages of both good harmonic characteristics owing to phase disposition modulation and power balance distribution for each H-bridge unit owing to phase-shift modulation. The proposed scheme can not only output five levels that have good harmonic characteristics,but also achieve the output power bal-ance in one output cycle for each cell. A cascaded inverter consisting of three cells is taken as an example in the simula-tion,and the result verifies the validity and superiority of the proposed topological structure and its control scheme.