The LLC resonance half-bridge converter is one of the most popular DC-DC converters and could easily inspire researchers to design a high-efficiency and high-power-density converter. LLC resonance converters have diverse operation modes based on switching frequency and load that cause designing and optimizing procedure to vary in different modes. In this paper, different operation modes of the LLC half-bridge converter that investigate different optimization procedures are introduced. The results of applying some usual optimization methods implies that for each operation mode some specific methods are more appropriate to achieve high efficiency. To verify the results of each optimization, numerous simulations are done by Pspice and MATLAB and the efficiencies are calculated to compare them. Finally, to verify the result of optimization, the experimental results of a laboratory prototype are provided.

Peer Reviewed