半桥级联型三相多电平逆变器及其控制

把传统级联型三相多电平逆变器的H全桥单元，改为半桥单元，可减少一半的功率器件数和两个主电源。分别分析了倍压、等压电源供电情况下的SPWM调制控制方法，以及调制结果。利用等能量和等电量方法，解出电源功率分配比和倒灌功率比。倍压电源供电逆变的倒灌功率，可通过增大电源电容量和PWM软件算法，使倒灌功率的影响减至很小。等压电源供电逆变，利用循环脉冲控制，可使除公用电源外的级联电源功率达到均衡。

Half-bridge Cascaded Three-phase Multilevel Inverter and Its Control

Changing H full bridge unit of traditional cascade three-phase multilevel inverter to half bridge unit can reduce the number of power devices by half and two main power supplies. This paper analyzes the SPWM(Sinusoidal Pulse Width Modulation) modulation control method under the condition of double voltage and equal voltage power supply and the modulation results. By using the method of equal energy and equal electric quantity, the power distribution ratio and backward power ratio of power supply are solved. By increasing the capacitance of power supply and PWM software algorithm, the influence of the backward power can be reduced to a small extent. The power of the cascade power supply can be balanced except the utility power by using the cyclic pulse control in the equal voltage power supply inverter.