A 500-W Wireless Charging System With Lightweight Pick-Up for Unmanned Aerial Vehicles

This letter develops a wireless charging system based on a novel orthogonal magnetic structure and primary-side power control to simplify the structure and reduce the weight of on-board pick-up for recharging the unmanned aerial vehicles (UAVs). The novel magnetic structure has a polarized transmitter with a flat U-type core and a perpendicular air-cored receiving coil, guaranteeing the magnetic flux operation space away from a UAV body by coil structure itself and also reducing the weight of a magnetic receiver. The power flow to the battery is controlled by the primary side based on charging current and voltage feedback by pick-up. Simulations based on ANSYS Maxwell and experiments are carried out to validate the proposal. The weight of a magnetic receiver is 130 g. And the system can deliver 500 W with a dc-to-battery efficiency of 90.8%, meanwhile 10 A constant current/50 V constant voltage charging for 12S lithium-ion battery is achieved by the closed-loop system.