Design and Analysis of Inductive Power Transfer System Using Nanocrystalline Flake Ribbon Core

This article proposes the design and analysis of an inductive power transfer (IPT) system that features novel nanocrystalline flake ribbon (NFR) cores. The flake ribbons are produced by compressing the dielectric material with nanocrystalline ribbons, leading to a reduction in the eddy current loss. A complete magnetic core is then fabricated by laminating the ribbons, imparting anisotropic properties. The article outlines the design methodology for NFR cores, considering this lamination characteristic in Double-D IPTs. Accordingly, NFR cores with a lamination factor of 0.375 and a core thickness of 3.2 mm have been designed, produced, and experimentally validated. The tests indicate an over 95% dc-dc efficiency and an over 96.3% ac-ac efficiency at the output power of 8.9 kW. To assess their thermal attributes, one-hour duration tests at continuous 6.6 kW operation were performed on NFR cores and ferrite groups. Results demonstrate that NFR cores maintain a cooler temperature at 76.4 degrees C, whereas the DMR44 and DMR95 reach 91.7 degrees C and 84.9 degrees C respectively. Additionally, the designed NFR cores have achieved 51% core weight reduction, 31% volume reduction, and 20% thickness reduction. The proposed NFR cores based on the design methodology can greatly enhance high power density IPT systems.