Low EMF three phase resonant magnetic field charger for drone with high Q reactive loop shielding

Abstract

Wireless power transfer (WPT) charging technology using magnetic field can transfer power to battery for drone without any electrical contact. It can be one of the safe and convenient battery charging methods. In spite of the great advantages, WPT system generates strong electromagnetic fields (EMFs), which causes interference on the electrical devices such as DGPS, speed controller, Bluetooth data link, and power distribution board in the drone. In this paper, we propose a three phase resonant wireless charger for drone operating at 60 kHz with low EMF and electromagnetic interference (EMI) by guided magnetic flux structure and 3rd harmonic elimination. In addition to additional EMF reduction, the high Q reactive loop shielding is proposed without additional power in three phase resonant magnetic field charging system. The magnetic field simulation results obtained using FEA simulation prove that the high Q reactive loop shielding can reduce fundamental magnetic field harmonics by 0.495 mG at center of the drone from center of the wireless charging platform. Moreover, the implemented three phase wireless charger complies with the ICNIRP guidelines published in 1998.