基于LLC谐振变换器的双向DC/DC变换器

Bidirectional DC/DC Converter Based on LLC Resonant Converter

在储能系统中,谐振型双向DC/DC变换器因为其优异的特性而得到广泛应用。提出一种基于LLC谐振型双向直流变换器,不仅具有LLC变换器高效率等优点,而且具有能量双向传输的能力。在电路中增加一个辅助电感,实现变换器在正向工作与反向工作时拓扑完全相同。变换器结构简单,无需任何辅助缓冲电路便能实现软开关,适合储能系统中能量双向流动的场合。在采用时域分析与基波分析对变换器的电压增益与软开关条件进行分析的基础上,对变换器的参数进行优化设计。搭建一台5 kW的实验样机,实验验证了变换器结构与设计方法的可行性以及运行效率的优越性。

Bidirectional resonant converters with outstanding performances are widely applied in the storage systems.According to the LLC resonant converter,a bidirectional DC/DC converter is proposed which not only has advantages in achieving high efficiency but also ability to transmit energy bidirectionally.An auxiliary inductor added in the converter achieves the converter to have the same topology in both forward and reverse operation.The converter has a simple structure and can realize soft switching without any auxiliary buffer circuit and is suitable for the occasion of energy bidirectional flow in the energy storage system.Based on the analysis of the voltage gain and soft switching conditions of the converter by time domain analysis and fundamental analysis,the parameters of the converter are optimized.A 5 kW experimental prototype is built to verify the feasibility of the converter structure and design method and the superiority of operating efficiency.