3D Modeling of Integrated Magnetics in High Frequency LLC Resonant Converters

Abstract

A novel structure of a planar transformer with magnetic integration is presented in this paper. The introduced transformer has a number of advantages and suitable for uses in the LLC resonant converter. The adjustment for the required resonant inductance of the LLC circuit is quite straightforward by controlling the distance of the magnetic bar to the magnetic core. However, it requires 3D FEM simulation of magnetic field analysis, in conjunction with the use of the energy method (due to the orthogonal structure of the windings and the insertion bar). Simulation results of the designed magnetics are presented in this paper. They are highly accurate according to the measurement results of a prototype. To optimize the resonant impedance, different insertion configurations of the magnetic bar have been investigated.