Application of Shielding Coils in Efficiency Optimization for Underwater WPT Systems

Eddy current loss (ECL) in seawater will reduce the efficiency of underwater wireless power transfer (WPT) systems. In this paper, we propose a method that taking advantage of inductive shielding coils to limit the electric field and reduce ECL in good conductor medium to improve transmission efficiency. Circuit models are applied to give a accurate and intuitive analysis of transmission characteristics and finite element analysis (FEA) is used to evaluate the electric field distribution. By comparing different structure WPT systems, we find that the proposed systems have a better performance in efficiency when they work with a high frequency and its highest efficiency is higher than the normal two-coil systems. The results show that making use of inductive shielding coils is another method to improve the transfer efficiency in underwater WPT systems.