A Three-Phase Underwater Wireless Power Transfer System with Robust Anti-Misalignment and Parameter Drift Tolerance for AUV Applications

Due to ocean current fluctuations, misalignment is prone to occur between autonomous underwater vehicles (AUVs) and charging docks. This induces drastic variations in the mutual inductance of underwater wireless power transfer (UWPT) systems, thereby leading to a significant decline in the power transfer capacity and efficiency of the system. Furthermore, parameter drift can significantly impact the implementation and operation range of soft-switching. To overcome these issues, this paper proposes a three-phase UWPT system employing a segmented fan-shaped coupler. This system demonstrates robust anti-misalignment performance under axial and angular misalignment conditions. Moreover, by integrating an active auxiliary network (AAN), the system enables zero-voltage switching (ZVS) over the full load range. The implementation of this soft-switching approach is not susceptible to the fluctuations of compensation parameter values and has a strong ability to resist such fluctuations. The operating principle of the proposed UWPT system is first elaborated. Subsequently, considering the dynamic marine environment, comprehensive rules for achieving full-range soft-switching are derived. The design methodology for the segmented fan-shaped coupler is then presented. Finally, a 1 kWexperimental prototype is built to validate the feasibility and performance of the proposed scheme.