Optimal Solutions for Underwater Capacitive Power Transfer

Abstract

Capacitive power transfer (CPT) has attracted attention for on-road electric vehicles, autonomous underwater vehicles, and electric ships charging applications. High power transfer capability and high efficiency are the main requirements of a CPT system. This paper proposes three possible solutions to achieve maximum efficiency, maximum power, or conjugate-matching. Each solution expresses the available load power and the efficiency of the CPT system as functions of capacitive coupling parameters and derives the required admittance of the load and the source. The experimental results demonstrated that the available power and the efficiency decrease by the increasing of the frequency from 300 kHz to 1 MHz and the separation distance change from 100 to 300 mm. The maximum efficiency solution gives 83% at 300 kHz and a distance of 100 mm, while the maximum power solution gives the maximum normalized power of 0.994 at the same frequency and distance. The CPT system can provide a good solution to charge electric ships and underwater vehicles over a wide separation distance and low-frequency ranges.

Conformal Transformation Analysis of Capacitive Wireless Charging

“…In a previous work [8], we showed that both the power transfer capability and the system's efficiency are a function of the admittance Y 12 . Increasing the mutual capacitive coupling can enhance the power transfer capability and the system's efficiency.…”

Wireless Power Transfer for Unmanned Underwater Vehicles: Technologies, Challenges and Applications

“…In the field of underwater energy transfer, some CWPT models and prototypes have already been tested in academic studies [80][81][82][83][84][85][86][87][88][89][90][91][92][93]. In most of these works, CWPT systems achieved a power transfer efficiency beneath 70% in seawater environments.…”

“…More recently, in a paper by Mahdi et al [92], authors studied the maximum power capability of a CWPT system by using network theory to then experimentally test it with a prototype in seawater. They were able to achieve an efficiency of 83% for a 100 mm gap and 300 kHz.…”

Modeling, simulation and experimental validation of solid media in capacitive wireless power transfer

“…In the literature, studies can be found on dielectric properties of water or skin and their behavior in a CPT system. However, these kind of studies are limited to low power transfer of less than 130 W [14][15][16][17]. Despite the profound knowledge on dielectric materials for capacitors, to the best knowledge of the authors, little is known about media different from air for CPT applications with 100 W or more.…”