Omnidirectional Wireless Power Transfer System with Hybrid Ladder-Shaped Magnetic Coupler for Planar Type AUVs

Wireless charging system for planar-type autonomous underwater vehicle (AUV) requires strong misalignment tolerance to possible simultaneous lateral, vertical offsets and inclination deviation in underwater environment. However, the majority of previous researches focused on cylinder-type AUV under lateral misalignment. To address this issue, a hybrid magnetic structure composed of a ladder-shaped coil and antiparallel windings for the AUV wireless charging system is proposed in this article. Specifically, employing Biot-Savart’s law, the hybrid transmitting coil is confirmed to generate a uniform magnetic field in the charging region by theorical and finite element analysis. The detailed optimization procedure of dimensional parameters is presented. A 400W experimental protype is implemented, achieving a maximum power transmission efficiency of 91.37%. The experimental results show that within the 30mm vertical offset, 30% diagonal offset range of the receiving coil size and the tilt angle of 15 degrees, the power transmission efficiency fluctuation is restricted by only 4.33%. It verifies that the proposed hybrid ladder-shaped magnetic structure is able to supply stable power to planar-type AUV under intricate position misalignments.