适用于高压宽输入新型三电平LLC谐振变换器

A Novel Three-level LLC Resonant Converter Suitable for High Voltage and Wide Input

在高压大功率轨道交通电源应用中,常使用三电平变换器,因其主开关管承受的电压应力仅有输出电压的一半。但是三电平输入电压高,伴随高开关损耗,导致效率低下,因此在使用三电平拓扑时需应用软开关技术以降低损耗。提出了一种适用于高压宽输入新型三电平LLC串联谐振变换器,该拓扑不仅能实现良好的软开关性能,而且能实现电流均衡。分析了该变换器的工作原理,通过仿真和实验对该拓扑的有效性进行了验证。

In the application of high-voltage and high-power rail transit power supplies,three-level converters are often used,because the voltage stress of the main switch tube is only half of the output voltage.However,due to the high three-level input voltage and high switching loss,the efficiency is low.Therefore,it is necessary to apply soft switching technology to reduce losses when using a three-level topology.A novel three-level LLC series resonant converter suitable for high voltage and wide input is proposed.This topology can not only achieve good soft switching performance,but also achieve current balance.The working principle of the converter is analyzed,and the validity of the topology is verified through simulation and experiment.