Experimental Investigation of Transfer Characteristics of Midrange Underwater Wireless Power Transfer

Abstract

The transfer characteristics of an underwater Wireless Power Transfer (WPT) system with a resonant frequency of 460kHz are studied experimentally. The coils have an outer diameter of 22.5 cm. Through this study, it was found that when the transfer distance is small, the transmission effect of WPT system in seawater is similar to that in air; when the transfer distance is larger than 20 cm, the load voltage of the WPT system in seawater is 4 times higher than that in air, and the transmission efficiency in seawater can reach 17 times of that in air on average. The experimental results in this paper are compared with studies published, and a circuit model is proposed to explain and predict the experimental phenomena, but the specific model still needs further work. Finally, the underwater WPT system has a low transfer efficiency of only 20% at midrange, so the findings of this research may be used for distance first scenarios.