Study on the Application of Nanocrystalline Magnetic Materials in Wireless Power Transfer Systems

Dr Chen Chen, City University of Hong Kong

Abstract: Magnetic materials such as ferrite are commonly used in wireless power transfer (WPT) systems to shield flux leakage and enhance coupling between the primary and secondary coils. However, their low saturation flux density often results in large volumes, while their brittle mechanical properties lead to reduced mechanical strength. This work innovatively explores the application of nanocrystalline magnetic materials in WPT systems. Their configurable permeability and flexible structure enable customized designs, particularly for non-planar installation scenarios. The crushed nanocrystalline core exhibits lower core loss than its non-crushed counterpart, with more severe crushing resulting in reduced permeability and loss. Moreover, the square crushing pattern produces more regular flakes and better insulation compared to dot crushing, thereby achieving lower core loss. Furthermore, a novel terrace-shaped nanocrystalline flake ribbon core (T-NFR) is investigated to mitigate non-uniform magnetic flux distribution, which helps achieve relative temperature balance and enhance system stability.

Speaker's Bio: Chen Chen received the B.Eng. and M.Eng. degrees in Mechanical Engineering from Wuhan University of Technology, Wuhan, China, in 2019 and 2022, respectively, and the Ph.D. degree in Electrical Engineering from City University of Hong Kong, Hong Kong SAR, China, in 2026. He is a Postdoctoral Fellow in the Department of Electrical Engineering at the City University of Hong Kong, as well as a member of the State Key Laboratory of Terahertz and Millimeter Waves. His current research interests include wireless power transfer, and applications of nanocrystalline magnetic material in power electronics.