中文摘要：

针对硬开关逆变器运行在高开关频率时，开关损耗较大，不利于效率提高的问题，提出一种适用于高开关频率的并联谐振直流环节软开关逆变器的拓扑结构。该拓扑结构的辅助谐振电路相对简单，通过辅助电路的谐振使直流母线电压下降到零时，逆变器的主开关可以完成零电压开关，同时辅助开关也可以在辅助谐振电路的工作过程中完成软开关，而且分压电容没有串联在逆变器的直流母线之间，因此该逆变器没有中性点电位的变化问题依据不同工作模式下的等效电路，对其工作原理进行了分析，给出了软开关的实现条件和逆变器的控制方法，并制作了一个5kW的实验样机。实验结果表明，逆变器的主开关和辅助开关器件都实现了软开关，该软开关逆变器能有效地降低开关损耗和提高效率。

英文摘要：

Switching loss was large when the hard-switching inverter was operated at high frequency. A high frequency parallel resonant DC link soft-switching inverter was proposed to overcome the problem. Auxiliary resonant circuit was relatively simple. When DC-bus voltage decreased to zero via the reso- nance of the auxiliary circuit, all main switching devices in the inverter was operated under zero-voltage condition. Auxiliary switching devices was also operated under soft-switching in the resonant process. Furthermore, the bulk capacitor was avoided in the circuit and there was no center tap potential variation problem. The operation principle was analyzed based on the equivalent circuits at different operation modes. The conditions of soft-switching and the control method of the inverter were also achieved. A 5 kW laboratory prototype was built. The experimental results demonstrated that soft-switching opera- tion of all switching devices were realized. Therefore, the soft-switching inverter presented effectively reduces switching loss and improves efficiency.