Rapid and Accurate Thermal Evaluation of IPT Pads Based on Pseudo-3D Finite Difference Method

As inductive power transfer (IPT) pads for electric vehicles (EVs) feature increasingly compact structures and higher power ratings, the significance of their steady-state thermal evaluation continues to grow. However, conventional temperature prediction methods rely on the finite-element-method (FEM) simulation, which characterizes intensive computational resources and time. To address this challenge, this article introduces a pseudo-3D finite difference method (P3D FDM) to facilitate the rapid and accurate thermal evaluation of IPT pads. Based on region division, the coil, ferrites, and aluminum plate are separated as thin layers, where only the 2-D horizontal heat transfers are considered in each layer. The vertical heat transfers between each layer, as well as the heat dissipation to ambient, are simplified as uniform thermal resistances. Then, the FDM is applied to the proposed P3D structure to obtain linearized thermal transfer equations. By specifying the boundary condition, these thermal transfer equations can be considered as explicit and directly solved for accurate temperature distribution without miscellaneous iterations. Prototypes with different wire diameters are built to verify the effectiveness of the proposed method. The results show that the proposed method is 550 times faster than the FEM simulation, and the maximum error is only 6.42%.