Design of Two Orthogonal Transmitters With Double L-Type Ferrite for the Wireless Charging System in Unmanned Aerial Vehicles

This article proposes a wireless charging system based on a novel magnetic coupler with high coupling capacity for recharging the unmanned aerial vehicles (UAVs). The novel magnetic coupler includes two transmitters and one receiver, in which the transmitters consist of double orthogonal rectangular coils and double orthogonal L-type cores and the receiver is an air-cored receiving coil perpendicular to one coil of the transmitter and parallel to the other coil of the transmitter. The magnetic flux is concentrated in the receiving coil as much as possible while guaranteeing the magnetic flux operation space away from a UAV body by coil structure itself. A prototype of the UAV wireless charging system based on the novel magnetic coupler is built and tested. The experimental wireless charging system designed for Phantom 4 RTK can deliver 102 W at a dc-to-battery efficiency of 91.02% at the maximum output power point, which is adapted to the wireless charging in UAVs.