Design of bidirectional power converters coupled with coils for wireless charging of AUV docking systems

The docking station is usually deployed at seafloor as a charging node to enhance the endurance of autonomous underwater vehicles (AUVs). However, for deep-sea observation requirements, it is nearly unaffordable to deploy extremely long cables to provide power for docking stations. Therefore, this paper proposes a possible power-supply solution by developing an underwater bidirectional wireless power transmission (UBWPT) system. To improve the efficiency of the UBWPT system in underwater scenarios, the power converters coupled with coils is designed by analyzing the eddy current loss and parasitic jumper capacitor in seawater. Additionally, two independent controllers are developed for the transmitting and receiving converters to achieve power flow control underwater. The effectiveness of the bidirectional power converters is verified by developing a 51-W charging prototype system, which improves the system efficiency by 3% in simulated seawater.