Conductive and Capacitive Properties of Couplers under Seawater for Electric Wireless Power Transfer

This paper analyzes the modeling and characteristics of parallel-plate capacitors for underwater capacitive wireless power transfer (CWPT) systems. Using finite element method (FEM) simulations, this paper investigates the impact of various simulation factors on the simulation results both for the capacitances and the conductances. A fitting equation is proposed for the coupling capacitance and conductance in seawater environment, which matches the simulation results well. Notably, this paper firstly demonstrates a ratio of around 295.9 at a frequency of 3 MHz between the real and imaginary parts of the coupling admittance. This result confirms that the conductance, rather than the susceptance, dominates the CWPT system for under seawater applications.