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

This letter introduces an innovative laminated core structure for high-power inductive power transfer (IPT) applications using Fe-based nanocrystalline materials. While these materials offer excellent core loss performance, traditional laminated cores often suffer from uneven flux density distribution. Additionally, 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 horizontal-laminated cores (H-cores) as the main flux conductors and vertical-laminated cores (V-cores) as flux balancers. Finite Element Method (FEM) 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 hotspots by a temperature reduction of over 35°C. Shielding loss is nearly reduced to zero. © 1986-2012 IEEE.