Resonance determination and readjustment of the wireless power transfer system for multi-device charging

Abstract

This research deals with magnetic resonant wireless power transfer (WPT) systems for multi-device charging. It is difficult to determine the resonance condition of the WPT systems for multi-device through a simple mathematical model, and the complexity of the WPT system increases due to the variation of the number of the charging devices, the relative position of the charging devices, and different rated power capacities. Also, when the relative positions or angles of multiple devices are changed, the magnetic flux linkages of each coil are changed so that the coupling effect is changed and the resonance conditions are changed accordingly. In order to overcome these difficulties of magnetic resonant WPT systems for multi-device charging, this study proposed the method of determining optimal resonant condition based on optimization. In addition, since the readjustment of the optimal resonant condition is difficult to be implemented in real time just through using optimization, the optimal resonant conditions were represented by the resonance information of the specific positions, which are achieved by the optimization. Finally, through this research, the possibility of readjustment of the resonance conditions in real time has been shown and the strategy of the stable and efficient WPT system for the multi-device has been proposed.