Hybrid Nanocrystalline Ribbon Core and Flake Ribbon For High-Power Inductive Power Transfer Applications

This article examines the performance of a 13-kW high-power inductive power transfer system utilizing a hybrid core structure with novel nanocrystalline ribbon cores and nanocrystalline flake ribbons. Conventional laminated nanocrystalline ribbon cores exhibit excessive edge losses due to high flux density concentrated on the edge and high eddy current losses in the lateral wall, potentially causing partial thermal runaway. To mitigate this issue, it is proposed to employ nanocrystalline flake ribbons as a shielding material on the edge while maintaining the nanocrystalline ribbon core as the main magnetic coupler. The performance of the hybrid core is evaluated under different power levels up to 13.8 kW. Experimental results reveal a nearly 2% increase in peak efficiency compared to the ferrite DMR44 and a 1% increase compared to standalone nanocrystalline ribbon cores, bringing the peak dc–dc efficiency to over 96%. Moreover, under 6.6-kW output power, the temperature rise after 2-h operation is significantly reduced to a maximum temperature of 76.5 °C with the proposed hybrid core, compared to 96.4 °C with the ferrite shield and 110.6 °C without any edge shield. The design highlights using nanocrystalline material in inductive power transfer systems to improve the efficiency and thermal performance.