Laminated Cores in Inductive Power Transfer: A Viaduct Structure for Balanced Flux and Minimal Shielding Loss

Abstract

This letter introduces an innovative laminated core structure for high-power inductive power transfer applications using Fe-based nanocrystalline materials. While these materials offer excellent core loss performance, traditional laminated cores often suffer from uneven flux density distribution. In addition, lamination gaps can increase leakage flux and shielding loss. To address these issues, we propose a viaduct lamination core structure inspired by viaduct bridges. This design employs horizontally laminated cores as the main flux conductors and vertically laminated cores as flux balancers. Finite-element method simulations demonstrate improved flux density and loss distribution, eliminating edge flux concentration. The design achieves a quasi-isotropic flux density distribution through anisotropic combinations. Experiments with up to 22-kW output power confirm the design's effectiveness, achieving a peak ac–ac efficiency of 97.4% and eliminating edge hot spots by a temperature reduction of over 35 °C. Shielding loss is nearly reduced to zero.