CLL Resonant Converter With Secondary Side Resonant Inductor and Integrated Magnetics

ACLLresonant converter with transformer–inductor-integrated magnetics is proposed. TheCLLresonant converter is derived by placing the resonant inductor of anLLCresonant converter on the secondary side of the transformer. In comparison with anLLCresonant converter, the circulating current associated with the magnetizing current of the transformer is removed from the resonant inductor. More importantly, the phase difference between the flux in the magnetic cores of the transformer and the resonant inductor becomes larger. Therefore, the flux of the transformer and inductor can be cancelled with each other, resulting in a reduced loss and volume of the magnetic core. A novel structure is proposed to integrate the transformer and inductor with integrated winding structures. Detailed analysis and optimized design of the integrated transformer–inductor are presented. The effectiveness and feasibility of the proposed solutions are verified with simulation and experimental results.