Experimental Investigation of the Eddy-Current and Dielectric Loss of Underwater IPT System

Inductive power transfer (IPT) technology has shown great potential in autonomous underwater vehicle (AUV) charging due to the removal of troublesome charging cables and no exposed metal plugs. However, the alternating magnetic field of the inductive charging system will induce extra eddy-current and dielectric loss in seawater due to plenty of ions and polar molecules of water. In this paper, an experimental investigation on extra power loss in saltwater is conducted under different magnetic flux intensities B and frequencies f
s
. Experimental results reveal the exponential relationship of the extra power loss in saltwater with B and f
s
with exponential coefficients of 2.0 and 2.165, and an empirical equation is developed to quantify the extra power loss, which contributes to the optimization and design of the underwater IPT system.