基于混合控制式交错并联LLC谐振变换器的充电模块研制

Development of Charging Module Based on Interleaving Paralleled LLC Resonant Converter with Hybrid Control

为了解决当前电动汽车充电模块效率低、功率小的缺点,提出了一种基于混合控制式交错并联LLC谐振技术的非车载式电动汽车充电模块整体设计方案。所述方案输入侧为VIENNA电路,输出侧为交错并联LLC谐振DC/DC变换器。采用交错并联技术减小输出电流纹波,提高充电模块输出功率的同时,采用移相变频混合控制策略,使得谐振变换器工作在较窄的频率范围之内,因此降低了磁性元器件设计难度,提高了充电模块的转换效率以及功率密度。给出了充电模块整体电路拓扑设计、各模块工作原理以及控制策略,研制了20kW原理样机,与纯变频式交错并联LLC谐振变换器充电模块的对比分析验证了所述方法的可行性。

In order to improve the efficiency of the charging module of electric vehicles,an overall design scheme for off-board charge based on hybrid control interleaving technique in the paralleling DC/DC converter is designed.In this scheme,VIENNA circuit is at the input side and the hybrid control interleaving parallel LLC resonant converter is at the output side.While reducing the output current ripple and improving the output power of charging module with interleaving paralleled technique,the hybrid control strategy of frequency changing phase shift is used to make the resonant converter work in a narrow range of frequencies to reduce the difficulty in magnetic element design,and improve power density and conversion efficiency.The overall topology design of the charging module,working principle of every module,and control strategy are given.A 20 kW prototype is developed,and the feasibility of the proposed method is verified by comparing with the charging module of pure interleaving paralleled LLC converter.