Parametric Modeling and Characterization of Leakage-Integrated Planar Transformer for CLLC DC#x2013;DC Converter

摘要

With an objective to accurately characterize the leakage inductances and winding resistances of a high-frequency planar transformer (HFPT) for a 500 kHz resonant CLLC converter, this article elucidates the correlation between various specifications involved in hardware fabrication of various winding configurations and their structural dependence on the resultant parameters. A precise analytical model is developed using 3-D finite element analysis (FEA) to synthesize the effective magnetic field and current density distribution in fabricated winding structures. Furthermore, a thorough analysis to study the interdependence of the resultant parameters on specifications such as printed circuit board (PCB) thickness and its fabrication layout, air gaps, and conductor thickness is presented for various winding configurations, thus elucidating various design-based tradeoffs. Also, frequency dependence of the obtained parameters is described which validates the optimal selection of winding configuration based on the effective gain magnitude for the CLLC converter topology. Detailed comparison between the developed analytical model with simulation model developed in Maxwell3-D and fabricated winding structures is presented, and the results validate the model accuracy, portraying an average mismatch of 3.8% and 6.2%, respectively.