A Cluster-Based Undersea Wireless Power Transfer System for Multiple Unmanned Underwater Vehicles

This paper presents a cluster-based undersea wireless power transfer (UWPT) system designed for the simultaneous charging of multiple unmanned underwater vehicles (UUVs). The system consists of one master and two slave charging stations, with a maximum power conversion capability of 5.0 kW. The architecture integrates a hybrid communication scheme—combining a LoRa radio-frequency (RF) link and a wired RS-485 bus—and intelligent monitoring for real-time data acquisition. Environmental sensors continuously collect salinity, temperature, and pressure. An experimental platform with three interconnected charging stations validated the concept. Experimentally, the system achieved a peak DC-DC transfer efficiency of 94.10% in air and 90.14% in saline water under 500 W–1 kW loads. During actual light-load UUV battery charging (~94 W), a stable real-time efficiency of 75.5% was maintained. The master station successfully performed coordinated power command issuance, allowing heterogeneous UUVs (24 V and 16 V) to be charged concurrently with stable output fluctuations below 2.3%. The underwater LoRa link (at 60 cm depth, 10 cm distance) operated reliably without packet loss. These quantitative results demonstrate the system’s robustness and provide a scalable solution for multi-vehicle undersea wireless charging applications.