Abstract
The conductive nature of seawater negatively affects inductive wireless power transfer (IWPT) systems by increasing power dissipation. The power loss appears as additional resistance in the real part of the impedances. This study presents an analytical model to calculate the additional resistances introduced by induced eddy currents in underwater wireless power transfer (UWPT) systems that operate with cylindrical coils. The main step of the study involves calculating the electric field intensities by solving Maxwell’s equations in different regions using the cylindrical coordinate system. Because of the coils’ structure, the surrounding conductive region is divided into three concentric cylindrical sub-regions by the coils. Each region is characterized by distinct electromagnetic properties, and cylindrical coils are located at the boundaries. Given that the boundary conditions are applied on cylindrical surfaces along the radial direction, the derived equations effectively describe the influence of key design parameters, such as coil turns, radii, distance between turns, operating frequency, and the properties of the sub-regions, all of which are integrated into the model. To validate the calculation, finite element method (FEM) analysis in ANSYS Maxwell is performed, demonstrating the high accuracy and reliability of the studied model.