3D Thermal Modeling of Inductive Power Transfer Coils Based on Basic Thermal Network for Optimization Analysis

Since the power transferred by inductive links is increasing, the design of the coils involved in this technology considering the power losses and the thermal behavior is very critical. This paper describes a simple analytical thermal modeling based on the combination of 2D-thermal networks to build a complex 3D-thermal model. The analytical equations are based on heat transfer theory and experimental correlations from the literature, and the model consists on the lamination of the 3D-geometry in 2D planes. The presented 3D-thermal modeling includes the modeling of the shielding, core-housing, magnetic core as well as the litz-wire that will be modeled as an equivalent layer to simplify the model based on homogenization of its parameters. Since the proposed model is based on analytical equations it is very fast to conduct a simulation and it can be used to analyze the geometries of the inductive coils in order to extract a design guideline to conduct fast designs taking into account the thermal results.