A Novel Precise Design Method for LLC Series Resonant Converter

Abstract

In this paper, a novel precise analysis method based on time domain analysis for LLC series resonant converter is proposed and a clear design guide line is given. Because LLC resonant converter has simple structure, high efficiency and high switching frequency capability, it is widely used nowadays. To achieve an optimized design and propose a clear design guide line, understanding its DC gain characteristic and parameters effect on efficiency is very important. Traditional analysis method based on fundamental-harmonic approximation can not give accurate results. Finally, following proposed design guide line, a prototype of MHz LLC series resonant converter with 96% efficiency has been built and tested. Experimental results testified the analysis method and proposed design guide line