Core Loss Optimization for Compact Coupler via Square Crushed Nanocrystalline Flake Ribbon Core

Nanocrystalline magnetic cores have been applied in inductive power transfer (IPT) systems as novel magnetic materials for their high saturation capability and flexible application. However, the loss of eddy current is still a primary concern in nanocrystalline material. This letter investigates two crushing patterns, namely, square-crushing and dot-crushing, for a nanocrystalline flake ribbon (NFR) to mitigate the eddy current loss in IPT applications. In the experiment, a 1-kW IPT prototype with a curved coupler for autonomous underwater vehicles is built to verify the loss performance. As a result, the coil with NFRs in the square-crushing pattern (S-pattern) has a higher quality factor than those with the NFRs in the dot-crushing pattern (D-pattern). Furthermore, the IPT system with the S-pattern NFR exhibits an ac–ac transmission efficiency of 93.51%, possessing 0.89% higher than that of the D-pattern NFR case. The utilization of the S-pattern NFR offers multiple benefits, including minimizing core loss and facilitating the advancement of IPT systems with increased power density and enhanced installation flexibility.