LLC谐振变换器交错并联技术研究

Research on LLC resonant converter interleaved parallel technology

LLC串联谐振变换器(LLC-Series Resonant Converter)因具有高效率、低EMI、便于磁集成等特有的优点而被广泛应用在现代电力电子设备中,但其本身固有的副边电流纹波系数大的缺点使得LLC-SRC难以被应用于低压大功率的场合。然而,两相或多相LLC-SRC交错并联技术能有效减小输出电流的纹波,提高电源的功率等级,但是并联又带来了负载不均流的问题。采用一种简单的并联结构,解决了两相LLC交错并联中负载不均流问题,300 W实验样机验证了理论分析的正确性和方案的可行性。

LLC series resonant converter has been widely used in modern power electronic equipments owing to its unique advantages,such as high efficiency,low EMI and convenient magnetic integration.However,the large output ripple current factor makes the LLC-SRC difficult to be applied in low output voltage and high power ratings.Fortunately,two-phase or multi-phase interleaved parallel technology should be a good alternative for this issue.But multi-phase parallel also brings a critical problem,that is the load current sharing.In this paper,a simple parallel structure was proposed for two-phase LLC interleaved parallel and the load current sharing problem was solved effectively.The 300 W prototypes validate the theoretical analysis and feasibility of the program.