Performance Analysis of a High-efficiency Multi-winding Wireless EV Charging System Using U-U and U-I Core Geometries

This paper provides an approach to use novel ferrite core geometries and winding configurations to improve effectiveness for electric vehicle wireless charging systems using magnetic resonant inductive power transfer (RIPT). Using ferrite magnetic cores improves the efficiency of IPT and magnetic resonance based IPT systems, and can reduce unwanted stray magnetic radiation in addition to improving coupling efficiency. Different ferrite geometries and various winding configurations are explored on U and I core geometries and their performance is studied using JMAG FEA analysis. Experimental results are shown for each core and winding configuration. From the analysis and the experimental results, it is seen that the U-U core based ferrite geometry system with windings close to the air gap provides the most efficient coupling in larger airgap RIPT applications. Design recommendations are given for a larger airgap WIPT system design.