DC/DC谐振变流器的研究

Study of DC/DC Resonant Converter

利用基波分析(FHA)法对DC/DC谐振变流器的稳态特性进行了初步研究和讨论。传统并联谐振变流器(PRC)及LCC谐振变流器的开关管关断损耗及空载环流损耗较为明显,整机变换效率难以进行优化设计。传统串联谐振变流器(SRC)的变换增益小于1,极大地限制了其应用范围。而LLC谐振变流器具有较宽的增益范围,折中了PRC和LCC谐振变流器的问题,拥有较高的变换效率,适合当今DC/DC高频开关电源装置的工程设计要求。300 W(12 V/25 A)LLC谐振变流器的样机满载效率超过95%,证明了理论分析的正确性。

The steady-state analysis of DC/DC resonant converter is preliminarily presented based on fundamental harmonic analysis （FHA）.Due to the high switch turn-off loss and high circulation loss with no-load,the conversion efficiency of the traditional parallel resonant eonverter（PRC） and the LCC resonant converter is hard to be optimized further.The conversion gain of the traditional series resonant converter（SRC） is always equal or even less than unit, which leads to the narrow application area directly.On the contrary,the LLC resonant converter compromises the drawbacks of the PRC and has much higher conversion efficiency, which means it can meet the current design re- quirement of DC/DC converter for industrial application.A 300 W prototype of LLC resonant converter is built up and its full-load efficiency higher than 95% verifies the accuracy of the theoretical analysis presented.