Novel Designs of Magnetic Coupled Structure With 360° Rotation Misalignment Tolerance for AUVs’ Wireless Charging System

Rotation misalignments cannot be avoided in an underwater wireless power transfer (UWPT) system of autonomous underwater vehicles (AUVs). However, the existing designs of magnetic coupled structures (MCS) in the AUVs' wireless charging system can only achieve rotation misalignment tolerance (RMT) in a certain range, which would limit its practical applications because of the dead areas where the coupling coefficients of the MCS have significant variations and may even approach to zero at some rotation angles. In this letter, a novel complementary enhancement MCS with a U-shaped bipolar coil transmitter and an arc-shaped unipolar receiver is first proposed, which can achieve full range of 360° RMT capability, thus keeping stable and highly efficient outputs under any rotation angles (0°–360°). Moreover, the MCS can be reconfigured by optimizing the dimensions and winding density based on simulated results. An experimental UWPT platform with 500 W/85 kHz is built to prove the effectiveness of our designed MCS. The measured results show that output powers can remain stable at 420 W under any rotation ranges, while the system efficiency is all over 87%. Simultaneously, the constant voltage with the maximum fluctuation error of 5.37% can be achieved under load changing from 10 to 50 Ω.