An Adaptive-Umbrella-Shaped Coupler with Low Leakage Magnetic Field for Ship Wireless Charging Systems

Ship wireless power transfer (SWPT) technology offers a safer alternative to conventional plug-in shore power systems that rely on exposed conductors. However, due to dynamic and multidirectional misalignments induced by ship swaying, high-power SWPT systems require robust magnetic shielding for couplers mounted on the ship hull. This article proposes a novel adaptive-umbrella-shaped (AUS) magnetic coupler with a soft magnetic core, which is deformed in response to misalignment. The coupler can maintain low leakage magnetic flux under multidirectional misalignment conditions. To analyze the dynamic, tightly coupled structure affected by misalignment, an analytical model for magnetic leakage is established. The design and optimization process of the AUS magnetic coupler are elaborated, with a 10 kW SWPT experimental platform developed for validation. When the coupler is aligned, the DC-DC efficiency of the SWPT system reaches 96.15%. Experimental results demonstrate that this novel magnetic coupler can reduce magnetic leakage to below 4.77 μT(rms) at a distance of 28 cm from the coil center, even under the worst scenario of misalignment. This value is significantly lower than the ICNIRP limit of 27 μT(rms) even in close proximity to the coupler.