Examination of Wireless Power Transfer Combined With the Utilization of Distance Detection

Abstract

Wireless power transfer using magnetic resonant coupling is expected to be widely used in the charging of an electric vehicle and in the use of home electric appliances. Wireless power transfer requires a high efficiency and power transfer over a long distance. However, the efficiency is reduced by the increase of the transmission distance and the change of the impedance of the receiving load. Therefore, a distance sensor using magnetic resonant coupling is proposed. In this paper, we propose a method of power transfer and distance detection using one couple of coils in real time. We also propose to use different frequencies in the power transfer and the distance detection, which are superposed and separated. Using the proposed approach, we demonstrated that the power transfer and the distance detection can be performed without relying on the change of the transmission distance.

Theoretical and experimental study of a wireless power supply system for moving low power devices in ferromagnetic and conductive medium

“…The wireless power transfer system could be utilized as a position sensor [20]. When the system is carefully designed to avoid the bifurcation phenomena, the position of the moving bar could be measured by simply tracking the resonance frequency that shifts with the variation of the magnetic coupling between the transmitter and the receiver coil.…”

Review of inductively coupled power transfer for electric vehicle charging

“…An automatic frequency tuning technique maintains the peak power transfer by changing the operating frequencies automatically based on the receiving current or receiving voltage [54, 74, 75]. However, this technique has limitations such as being incapable of maintaining constant output voltage in high misalignment condition and synchronisation errors between the four transistors in the full‐bridge inverter resulting in switching mismatch and high switching loss [7, 72].…”