Efficiency study for a 150W LLC resonant converter

The paper presents and analyzes the efficiency of a 150 W LLC resonant converter in order to compare with the results obtained with a conventional 150 W flyback version. The experimental results of the LLC resonant converter show a maximum efficiency of 94%, and an efficiency of 92% under a full-load condition. Using the presented theoretical equations and design methods, the power losses of the LLC resonant converter are measured and compared with those of a flyback type. Moreover, the switching losses of power switches, the losses of output-power diodes, and the losses of the transformer are considered in the design of the LLC resonant converter.