Wireless Power Transfer Platform to Re-charging UAVs using Sandwich Coils with Planar Ferrite Cores and Renewable Source

The limitations of UAVs in terms of their endurance or flight time are largely determined by the battery capacity. Because the weight of the battery unit is a significant factor, there is a trade-off between battery capacity and weight. This has led to the need for recharging or battery swap during UAV operations. To overcome this limitation, improving the potential battery energy density per kilogram or enhancing the ease of recharging. One solution is wireless charging system using sandwich coils. Magnetic coupler is the key component to reduce leakage flux that is harmful for human body and surrounding equipment. This paper presents real experimental data of sandwich coils performance with different alignment and ferrite I core orientations, and evaluations of the minimum leakage flux and maximum efficiency. Based on the experimental data, we successfully built a smart 5W prototype to test the concept of conveniently charging small UAVs using solar panels and a battery with sandwich coils and ferrite I cores.