An Energy‐Sharing Wireless Power Transfer System for Autonomous Underwater Vehicles

Inductive wireless power transfer (WPT) technologies have been widely used as an energy supplement for autonomous underwater vehicles (AUVs). It almost focuses on unidirectional power transfer in the marine environment, but there lack studies on energy‐sharing mode among AUVs. Based on the bilateral inductor‐capacitor‐capacitor (LCC‐LCC) resonant compensation network, this paper proposes an energy‐sharing WPT system for two AUVs. First, a specific magnetic coupler with strong antimisalignment capabilities, particularly in terms of rotation between the energy dock and AUVs, is proposed. The equivalent model of eddy current loss of the magnetic coupler in seawater medium is analyzed and measured. Second, the analytical formulas of the total transfer efficiency are derived and the relationship between coupling coefficients and transfer efficiency is analyzed. Finally, the experimental prototype including two WPT systems is implemented. The experimental results show that the maximum transfer efficiency in seawater medium is 93.22%, which is only 0.74% lower than that in air when operating under unidirectional transfer mode. The maximum efficiency of the energy‐sharing mode could achieve 86.95% between two AUVs in the seawater medium.