新型并联谐振直流环节软开关逆变器

提出了一种新型并联谐振直流环节软开关电压源逆变器的拓扑结构。通过在传统硬开关逆变器的直流环节添加辅助谐振单元，使直流母线电压周期性地归零，实现逆变桥开关器件在零电压条件下完成切换，且辅助开关器件承受的电压不超过直流电源电压；通过控制辅助开关器件，可以减小直流分压电容存在的电压偏差，对其工作原理进行分析，给出不同工作模式下的等效电路图。通过5kW的样机试验，结果验证了该谐振直流环节逆变器的有效性。

New Soft-Switching Inverter with Parallel Resonant DC Link

A novel with soft-switching voltage source inverter was proposed with a simple topology, an easy control strategy, high efficiency and high power density. Auxiliary resonant unit was added to DC link of conven- tional inverter to make DC-bus voltage decrease to zero periodically, which realizes zero-voltage operation of all switching devices in the inverter. Furthermore, the voltage across auxiliary switching devices does not exceed the voltage of DC power. In addition, the voltage unbalance of the DC-link capacitors can be reduced by controlling auxiliary devices. The equivalent circuits at different operation modes and the analysis of the circuits were presen- ted. A 5 kW laboratory prototype was built. The experimental results confirm the validity of the resonant DC link in- verter presented.