Frequency optimization of the AUV wireless charging system for minimum energy dissipation

With the growing demand for ocean exploration, research on docking technology is gaining popularity, resulting in the development of various types of docking systems. In contrast to traditional cable-based systems, this paper introduces a self-powered docking system designed for AUV recovery and recharging. To minimize energy loss in the self-powered system, an analysis of eddy current loss produced by the coils in the seawater is conducted, and a calculation method for determining the equivalent eddy current impedance is proposed. This allows for the transformation of energy loss analysis from the magnetic field to circuit analysis. Then the efficiency of the inductively coupled power transmission system in seawater is analyzed, and a frequency optimization method is proposed to minimize dissipated energy during the AUV battery charging process. Finally, the effectiveness of the frequency optimization method is validated through laboratory experiments. Moreover, the results of the sea trial confirm the feasibility of the optimal wireless charging system operating in a seawater environment. •An accurate eddy current loss calculation model is established for the coaxial coreless coils.•Frequency optimization method of the AUV wireless charging system is proposed to minimizing the dissipated energy.•A self-powered docking system is proposed and its ability of AUV recovery and recharge is verified in the sea trial.