A Novel Arc-Shaped Lightweight Magnetic Coupler for AUV Wireless Power Transfer

The underwater wireless power transfer (UWPT) technology provides a feasible way to solve the problems of the traditional power supply method of the autonomous underwater vehicle (AUV). The magnetic coupler is the most essential component in the wireless power transfer system. Its configuration determines its applicable scenarios, and its parameter design and optimization will directly affect the system's overall output power and efficiency. In this article, an arc-shaped underwater wireless power transfer magnetic coupler is proposed, which is suitable for AUV's curved shell. Especially, the proposed novel magnetic coupler utilizes Fe-based nanocrystalline alloy soft magnetic material as the magnetic core. Both volume and weight of the receiver are reduced compared with the traditional Mn-Zn ferrite material. Fe-based nanocrystalline alloy material provides a novel design idea for the magnetic coupler on electrical equipment with special-shaped shell due to its flexibility. A prototype of the UWPT system for 320 mm diameter AUV is built, and it can transfer 3 kW power in the experiment with a dc–dc efficiency of 91.9% at the forward maximum output power point. Compared with the structure with ferrite core, the volume of the proposed structure is reduced by 41.1%, and the weight is reduced by 42.6%, so that the expected effect has been achieved.