混合级联H桥逆变器的倍频调制及功率平衡方法

DOUBLE-FREQUENCY MODULATION AND POWER BALANCE METHOD FOR HYBRID CASCADED H-BRIDGE INVERTER

为消除电流倒灌问题和实现倍频调制,提出一种电压比为1∶1∶2∶2的混合级联H桥十三电平逆变器拓扑和一种混合载波移相调制方法。同时,为解决逆变器中高压单元的功率平衡问题,还给出一种基于逻辑运算的功率平衡方法。仿真和实验结果表明:该文所提混合载波移相调制方法可使该混合级联H桥逆变器具有4倍频特性和保证高压单元工作在基波频率,并且经过功率平衡控制后还可实现逆变器中高压单元之间的功率平衡。

In order to eliminate the reverse current problem and realize the double-frequency modulation,a hybrid cascaded H-bridge(CHB)13-level inverter topology with a voltage ratio of 1∶1∶2∶2 and a hybrid phase-shift pulse width modulation(PS-PWM)method are proposed. Simultaneously,in order to solve the power balance problem of the high-voltage cells in the inverter,a power balance method based on logic operation is also presented. The simulation and experimental results show that the hybrid PS-PWM method can make the hybrid CHB inverter have 4 times frequency characteristics,can ensure the high-voltage cells tooperate at the fundamental frequency,and can also achieve the power balance of the high-voltage cells after power balance control.