An LCC-S-S Compensated Three-Coil Wireless Charging System for Offshore USV Charging

In oceanographic research, unmanned surface vehicles (USV) are commonly employed for the purpose of gathering real-time data. However, because of their small battery capacity, frequent manual recharging limits their operational effectiveness. This research offers a three-coil inductive power transfer (IPT) system-based wireless charging method designed specifically for USV. A dedicated transmitter pad with an intermediate coil at the docking station and a tiny receiver coil integrated into the USV are components of the proposed system. This design primarily addresses the issues of space limits within USVs, appropriate wave motion, and sea level misalignment that lead to efficiency degradation. Moreover, an LCC-S-S compensation topology is proposed for the three-coil structure with detailed parameter design to provide constant current output. Finally, an experimental prototype of the wireless charging system is built to verify the output characteristics and performance of the system. Experimental results demonstrate the output performance of the proposed system, achieving a peak DC-DC efficiency of 91.3% and a maximum coil efficiency of 97.7% under alignment while maintaining 86.8% DC-DC efficiency with significant misalignment.