中文摘要：

为提高逆变器的效率,提出一种新型并联谐振直流环节软开关逆变器的拓扑结构。直流环节电压可以周期性下降到零,使逆变器的主开关完成零电压切换,同时辅助开关也实现了零电压开关或零电流开关。此外,辅助谐振电路中有2个辅助开关相串联,构成了双向开关。控制该双向开关的通断可以调节逆变器直流环节的零电压持续时间,以方便应用各种灵活的脉宽调制策略。依据不同工作模式下的等效电路图,分析电路的工作原理,给出设计规则,建立辅助谐振电路中各器件的功率损耗和分压电容的电压变化量的数学模型。制作了1台功率为3k W的实验样机,实验结果表明逆变器的主开关和辅助开关都实现了软开关。因此该软开关逆变器可以有效降低开关损耗。

英文摘要：

A novel parallel resonant DC link soft-switching inverter was presented to improve the inverter efficiency. The voltage on DC link decreased to zero periodically. Main switches could be operated under zero-voltage and auxiliary switches could be also operated under zero-voltage or zero-current. In addition, by controlling a bidirectional switch composed of two series auxiliary switches in the auxiliary circuit, du-ration of zero-voltage on the DC link in the inverter was regulated to apply flexible pulse width modulation strategy . Based on equivalent circuits in different modes, the operation principle was analyzed and design rule was presente. Besides, the mathematical models for auxiliary resonant circuit loss and voltage devia-tion of voltage dividing capacitors were also established. A 3kW laboratory prototype was built. Experi-mental results demonstrate that soft-switching operation of all main switches and auxiliary switches could be realized. Therefore, the soft-switching inverter presented can effectively reduce switching loss.