Experimental Results and Analysis of Wireless Charging Technology for Equipment Under Seawater

A constant current constant voltage charging scheme based on a single-ended primary inductive converter is proposed to address the key issues of wireless power transfer (WPT) technology for charging devices in seawater environments. The scheme can effectively adapt to the complex transmission conditions of a WPT system in a seawater environment by using the advantages of single-ended primary inductor converter (SEPIC) topology, such as adjustable voltage, wide input range, and the same polarity as output; its regulating effect on charging current and voltage is modeled and analyzed. An underwater experimental platform is built to test the charging performance of the system under different transmission distances, radial offsets, and deflection angles (1 A is set for the constant current stage and 5 V for the constant voltage stage). The experimental results show that when the distance is 2 cm, the maximum fluctuation amplitude of the current is 0.04 A. When the transmission distance is increased to 6 cm, and a radial offset of 5 cm is introduced, the fluctuation amplitude increases to 0.13 A. Under the condition of dynamic charging, the maximum fluctuation range of current is 0.15 A, and the fluctuation rate reaches 16.7%. It shows that the system has good applicability and application prospects in seawater environments.