The Design of a Multilayer Planar Transformer for a DC/DC Converter with a Resonant Inverter

Multilayer planar transformers are widely implemented in power electronic applications (power supplies, inverters, drives, resonant converters). The design process of these elements is complicated due to the complexity of a magnetic circuit and high frequency interactions between windings (leakage inductances, stray capacitances, skin and proximity effects, etc.). Additionally, an analytical approach to the analysis (based on mathematical formulas) can be uncertain. The applied FEM method of the analysis can be a solution to the above mentioned problems and this method was implemented in this paper. The description of scientific problems includes a presentation of a complex geometry of a planar transformer prototype with a ferrite magnetic core and PCB windings. The FEM model of a transformer was developed as the COMSOL 2D axial symmetry case and presented with implemented mathematical formulas, sequences of analyses, meshing aspects and combined with an Electrical Circuit interface. Results of the FEM analyses were compared with laboratory measurements of a transformer prototype.