The Relationship Between Charging Distance and Efficiency in Wireless Charging for Unmanned Aerial Vehicle

Abstract

The short endurance of unmanned aerial vehicles and the need to frequently interrupt missions to recharge them severely limit their ability to operate continuously in areas such as logistics, inspection and rescue. Wireless charging technology, especially electromagnetic induction power transfer, provides a viable solution for unmanned aerial vehicles to achieve continuous power supply in the air, but the sharp decrease of its transmission efficiency with increasing distance is the key challenge. This paper focuses on the bottleneck of unmanned aerial vehicle endurance and studies the in-air charging efficiency of the electromagnetic induction wireless power transmission system, with an emphasis on exploring the impact of charging distance (represented by the coupling coefficient k) on the transmission efficiency. This paper sorts out the classification of wireless power transmission technology, analyzes the structure and working principle of electromagnetic induction systems, and discusses the key factors affecting efficiency. An initial baseline was established using a simplified simulation model that omitted resonant compensation. As anticipated, both output voltage and efficiency were observed to decline markedly as the distance increased (and the coupling coefficient k decreased), even over short ranges. These baseline outcomes highlight a fundamental limitation of inductive coupling and reinforce the necessity of resonant compensation networks in real-world applications, as will be elaborated in the subsequent section. This research provides an important basis for the optimal design of the wireless charging system for unmanned aerial vehicles.