A Multiload WPT System with CC/CV Output Based on LCC-S Topology for UAV Clusters

Recently, with the widespread application of UAVs in multiple fields, a single UAV can no longer meet complex tasks, and UAV cluster that collaborate to complete tasks are becoming increasingly popular. Wireless power transfer (WPT) technology offers a power supply approach with high reliability and safety that could effectively improving the endurance of UAV clusters. In this paper, a multiload WPT system with constant current/voltage (CC/CV) charging mode based on LCC-S topology for UAV clusters is proposed. The method for implementing CC and CV charging mode is derived with theoretical analysis, which can be accomplished by switching the operating resonant frequency. Besides, a transmitter coil with uniform magnetic field distribution is designed in this manuscript, which can effectively guarantee that each UAV in the cluster receives the equivalent power. Subsequently, a WPT charging platform suitable for two UAVs is established. It has been proven by experiment that the proposed WPT system can concurrently supply power to two UAVs, while the two UAVs could simultaneously achieve CC and CV charging modes independent of load resistance variations. The variation ratio of charging current and voltage with load resistance change in CC and CV stage can be maintained below 4.5% and 5.2%, respectively.