Design and Implementation of Wireless Charging Infrastructure for Autonomous UAV Charging

Unmanned Aerial Vehicles (UAVs) have found widespread adoption across diverse application domains; however, their operational range remains severely limited by battery capacity, necessitating frequent manual recharging. This constraint significantly hampers their autonomous deployment in real-world missions. To overcome this limitation, a fully autonomous UAV ecosystem must be established, wherein wireless charging plays a pivotal role. Resonant Inductive Power Transfer (RIPT) has emerged as a promising technology for enabling contactless power delivery to lightweight UAVs, eliminating the need for human intervention. While several studies have explored coil optimization and the extension of the power transfer region, most focus on isolated subsystems and do not present a complete, practically validated solution tailored for autonomous UAV charging. In response, this paper presents a compact, lightweight, and misalignment-tolerant Resonant Inductive Power Transfer (RIPT) architecture specifically tailored to UAV platforms. A 105 W SS-RIPT system operating at 85 kHz is designed and experimentally validated, achieving a stable charging output of 21 V and 5 A under nominal alignment, with reliable operation sustained even under lateral misalignment up to 100 mm (corresponding to a coupling coefficient drop from 0.2 to 0.1). The system demonstrates an overall end-to-end efficiency of 86.77%, with inverter-stage ZVS operation experimentally confirmed. In addition, integrated protection mechanisms—including overcurrent, thermal, and open-load safeguards—ensure functional safety under practical deployment scenarios. By comprehensively addressing power transfer efficiency, misalignment robustness, and essential safety mechanisms through a practically implemented charging hardware setup, this work provides a validated pathway toward the realization of autonomous UAV charging infrastructure, while clarifying that the present focus is limited to the charging hardware rather than the complete autonomous ecosystem.