Adjustment of Transmitter Coil Current Ratio in Two Transmitter and Two Receiver Wireless Power Transfer System

Abstract

When one or two mobile devices are placed on a wireless charger consisting of two transmitter coils, a power transfer efficiency varies with a ratio of the current of each transmitter coil. Therefore, this paper proposes a transmitter coil current ratio for high power transfer efficiency in the wireless power transfer system with two transmitter coils and two receiver coils. The proposed coil current ratio is calculated using mutual inductance values between each transmitter coil and each receiver coil. Moreover, the mutual inductance extraction method is also proposed by analyzing the input current. The power transfer efficiency increases up to 8 % by applying the proposed transmitter coil current ratio.