Development of a Fast-Charging Platform for Buried Sensors Using High Frequency IPT for Agricultural Applications
Juan M. Arteaga, Paul D. Mitcheson, Eric M. Yeatman
Abstract
This paper describes the methodology and experimental results for wireless power delivery to a soil-sensors power and data distribution unit from an unmanned aerial vehicle (UAV), using a high frequency inductive power transfer (HF-IPT) link. The configuration features, at the transmit side, a lightweight single-turn air-core coil driven by a 13.56 MHz Class EF inverter mounted on a Matrice 100 drone by DJI, and at the receive side, a two-turn PCB coil with a voltage-tipler Class D rectifier, an off-the-shelf 42 V battery charger and a supercapacitors module for energy storage. The experiments were conducted with a coil-to-coil gap of 250 mm, which corresponds to a coupling factor lower than 5%. In the experiments, a 10 F, 42 V supercapacitors module was charged in eleven minutes with an energy efficiency of 34% from the 80 V DC source that feeds the inverter on the drone to the supercapacitor-based energy storage unit in the sensor module. At higher power (50 W) the HF-IPT system was able to achieve a 68% DC-DC efficiency with a coupling factor of 3.5%. The work reported in this paper is part of a multiple-discipline project which looks to enable the optimal usage of water in agriculture with broader sensing techniques and more frequent sensing cycles.