辅助电路无耦合电感的箝位谐振直流环节逆变器

Clamping Resonant DC-link Inverter With No Coupled Inductors in the Auxiliary Circuit

为提高逆变器的效率和降低辅助谐振电路的损耗,提出一种新型箝位谐振直流环节逆变器,其辅助电路中无耦合电感,可简化电路的分析与计算。由于引入了箝位电路,逆变器直流环节最高电压被箝位在直流电源电压的1.01~1.1倍。在逆变器主开关需要切换时,通过单独开关控制辅助谐振电路,使直流环节电压波形形成零电压凹槽,逆变器的主开关能完成零电压软切换,辅助开关能完成零电流软开通和零电压软关断。基于各工作阶段的等效工作电路,分析电路工作过程,得到完成软切换的条件和参数的具体设计步骤,构造一台10k W的实验样机。从实验结果可以看出,逆变器的主开关和辅助开关实现了软开关,因此该新型箝位谐振直流环节软开关逆变器能有效降低开关损耗和改善效率。

A new clamping resonant dc-link inverter was proposed to improve the efficiency and reduce the auxiliary resonant circuit loss. With no coupled inductors in the auxiliary circuit, it could bring convenience to analyze and calculate the circuit. Because of the clamping circuit, the maximum voltage across the dc-link inverter devices was maintained at around 1.01–1.1 times of the input source voltage. When all main switches in the inverter needed operating, the dc-bus voltage decreased to zero via the single switch which controlling the resonance of the auxiliary circuit. Then the main switching devices in the inverter were operated under zero-voltage condition and auxiliary switching device was turned on under zero-current condition and turned off under zero-voltage condition. The operation principle was analyzed based on the equivalent circuits at different operation modes. The conditions of soft-switching and the process of parameter design were also achieved. A 10 k W laboratory prototype was built. The experimental results demonstrated that all main switching devices realized soft-switching. Therefore, the novel clamping resonant dc-link inverter can effectively reduce switching loss and improve efficiency.