The Structure and Modelling Method of Integrated LLC Transformer with Wide Range Resonant Inductance Regulation

The integrated magnetics technology is famous both in academic and industry applications to achieve low profile and high power density of the power supply. The integrated transformer is widely used in LLC converter, where the transformer and resonant inductor are integrated in a magnetic component. But the regulation range of traditional integrated transformer structure is limited due to the low profile and small volume. In this paper a new leakage inductance regulation method is proposed, and then based on the two-dimensional equivalent model of the structure and the distribution of the leakage magnetic field, the leakage inductance calculation model of the transformer structure was established. The proposed structure can not only improve the regulation range of leakage inductance but also be easily achieved in the planner structure. Finally, the simulation results and prototype experiment results verify the correctness and flexibility of the theoretical analysis.