A Novel Magnetic Coupler With Low Leakage EMF for AUV Wireless Power Transfer System
Yanling Li, Kaiwen Xie, Yangjiang Ying
Abstract
The leakage electromagnetic field (EMF) in wireless charging system for autonomous underwater vehicles (AUVs) not only leads to a reduction in power transmission efficiency but also interferes with the electronic equipment on board. In this article, a novel magnetic coupler is proposed for AUVs. Transmitting (Tx) coils are vertically arranged to generate an toroidal magnetic field that can effectively concentrate the magnetic flux within the coupler, thereby minimizing the EMF leakage. Receiving (Rx) coils are designed to embed into the tail vanes to spare the space for AUVs. To achieve a good shielding effect and simultaneously meet the demands for power transmission, an optimization model is established to determine the Tx coils number. Experimental verification in seawater is conducted on laboratory prototype platform. The results demonstrate that the coupler can effectively limit the leakage EMF within the standard range. Two target planes are chosen for assessing the magnetic field strength. For plane I, the average magnetic field density can be restricted to 7.44 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> T, while for plane II, the value is 5.87 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> T. For the power transmission performance, both the output power and PTE increase with the number of Rx coils, ranging from 125.33 W and 80.22% to 362.68 W and 81.42%, respectively.