Exciting Voltage Control for Transfer Efficiency Maximization for Multiple Wireless Power Transfer Systems

The majority of wireless power transfer (WPT) systems transfer power in a directional manner. Recently, omni-directional WPT systems have been addressed by several research groups. This paper describes a discrete exciting voltage control technique for wireless power transfer via magnetic resonant coupling with multiple orthogonal transmitter coils which can maximize the power transfer efficiency in response to the change of coupling status. The theory allows the equations of the efficiency of the system to be determined at all the rate of the mutual inductance. The calculated results are included to confirm the advantage to one directional WPT system and the validity of the theory and the equations.