一种新颖的零电压开关PWM组合式三电平变换器

A NOVEL ZERO-VOLTAGE-SWITCHING PWM COMBINED THREE-LEVEL CONVERTER

该文提出一种新颖的零电压开关组合式直流三电平变换器,它实质上是由半桥三电平变换器和全桥变换器组合而成。该变换器所有开关管的电压应力均为输入电压的一半,特别适用于高压输入场合;其输出整流电压交流分量很小,可以大大减小输出滤波器的体积,提高变换器的动态性能;其输入电流脉动很小,可以减小输入滤波器;此外,该变换器可以在三电平和两电平两种模式下工作,输入整流二极管电压应力小,适合于宽范围输入电压场合。该文介绍了该变换器的工作原理及其特性,并给出实验结果。

A novel zero-voltage-switching （ZVS） PWM combined three-level （TL） converter is proposed. It is essentially a hybrid combination of a half-bridge TL section and a phase-shifted full-bridge section. The main advantages of the proposed converter are as follows： the voltage stress of all switches is ensured to be only the half of the input voltage; the secondary rectified voltage has low high-frequency content which can reduce the output filter significantly; the voltage stress of the rectifier diodes is reduced; the input current of the converter has quite little ripple, and as a result, the input filter can also be minimized. A prototype converter has been tested for the verification of the principles and advantages.