Airborne-Side Capacitive Tuning Strategy for Magnetically Integrated LCC/S WPT System Enabling High-Efficiency Wide-Load-Range Constant-Current Output in UAV Applications

For UAV battery charging, wireless power transfer (WPT) systems require load-independent constant-current output (CCO). Conventional designs face limitations in efficiency, output current, and system size. This paper introduces a compact, magnetically integrated LCC/S WPT system, where transmitter coil and compensation inductor are coaxially stacked, reducing volume versus standard SS topologies. The system achieves load-independent CCO and zero phase angle via receiver-side capacitor tuning, with output current unaffected by transformer parameters. Parameter selection is straightforward, and compatibility with various transformer configurations is enabled by single-capacitor adjustment. Experimental results from a 60 V, 4.9 A prototype confirm high efficiency and stable CCO across wide load ranges and misalignment scenarios, outperforming conventional SS setups and providing a cost-effective solution for UAV wireless charging.