Toroidal-Shaped Coils for a Wireless Power Transfer System for an Unmanned Aerial Vehicle

Abstract

Unmanned aerial vehicles (UAVs) using communications, sensors, and navigation equipment will play a key role in future warfare. Currently, UAVs are monitored to prevent misfire and accidents, and the conventional method adopted uses wires for data transmission and power supply. The repeated connection and disconnection of cables increases maintenance time and harms the connector. For convenience and stability, a wireless power transfer system to power UAVs is needed. Unlike other wireless power transfer (WPT) applications, the size of the receiving coils must be small, so that the WPT systems can be embedded inside space-limited UAVs. The small size reduces the coupling coefficient and transfer efficiency between the transmitting and the receiving coils. In this study, we propose a toroidal-shaped coil for a WPT system for UAVs with high coupling coefficient with minimum space requirements. For validation, conventional coils and the proposed toroidal-shaped coil were used and their coupling coefficient and power transfer efficiency were compared using simulated and measured results. The simulated and measured results were strongly correlated, confirming that the proposed WPT system significantly improved efficiency with negligible change in the space requirement. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ⓒ

Design of a Wireless Power Transfer System With Two Inputs With Large Voltage Differences for Missiles Mounted on Maritime Vessels

“…In general, 85 kHz is mainly used in a high-power WPT system for an electric vehicle wireless charging system [25]. However, in this study, as in (7), even when a relatively low voltage (V ESS ) is applied to the input, the output voltage of the rectifier must be within the range of the input voltage of the dc to dc converter in Table V. Since the input voltage range of the dc to dc converter is proportional to the operating frequency of the WPT system as in ( 7), a higher frequency of 105 kHz is selected.…”

“…In order to calculate the maximum voltage difference that the proposed system can handle, let the RX rectifier output voltage by the ESS power supply in (4) (V rect-ESS ) be equal to V min , and V rect-GEN in (5) equal to V max . The V rect-ESS is equivalent to (7), and V rect-GEN is equivalent to (11). Then, the ratio of V ESS and V GEN is as follows ( 14).…”

“…Typical applications include electric railways, electric vehicles (EVs), drones, and automated guided vehicles (AGVs) [4]- [6]. In addition, in recent years, the WPT system has been widely applied to unmanned aerial vehicles (UAVs) and missiles that are often used in military activities [7].…”

“…In previous studies, WPT systems for missiles or unmanned aerial vehicles have been proposed [7], [14]. However, these studies do not specifically differentiate between the operating load and the RX sensors load, so there is a limitation that these are difficult to apply to an actual missile system on the maritime vessels.…”

Free-Positioning Wireless Power Transfer Using a 3D Transmitting Coil for Portable Devices

“…Wireless power transfer (WPT) has attracted much attention because of its potential application in consumer electronic products, portable devices, robotics, electric vehicles, and charging systems [1][2][3][4][5][6]. With the occurrence of portable device explosion, the demand for wireless charging is necessary to reduce the mass of the traditional wire charge system.…”