多路隔离输出LLC谐振变换器的设计

Design of LLC Resonant Converter with Multiple Isolated Output

针对高效率、高功率密度和多路隔离输出的要求,结合LLC谐振变换器和反激变换器的拓扑优点,提出了一种基于对称谐振电容的多路隔离输出LLC谐振变换器,实现了一次侧功率管ZVS、二次侧二极管ZCS和多路多电压等级隔离输出。阐述了对称谐振电容LLC谐振变换器的工作原理,给出了输出主回路的选择和软开关实现的条件,进行了阻抗和谐振腔的参数设计。最后,研制了150W试验样机,试验结果验证了设计的可行性,同时电路结构拓扑简单且能够很好地满足设计需求。

To meet the requirements of high efficiency, high power density and multiple isolated output, a multiple isolated output LLC resonant converter was proposed with symmetrical resonant capacitor, which combines with the advantages of the LLC resonant converter and flyback converter. The primary power switch and secondary diode under ZVS and ZCS conditon and multiple isolated output are realized. The working principle of LLC resonant converter with symmetrical resonant capacitor was described. The selection of output main circuit and the conditions of soft switching were given. At the same time, the parameters of impedance and resonant network were designed. Finally, a 150 W test prototype was developed. The experimental results verify the feasibility of the design, and the circuit topology is simple and can meet the design requirements well.