Selective wireless power transfer using two transmission coils sandwiching reception coils

In this paper, a selective wireless power transfer system using two transmission coils is proposed. In this system, a magnetic resonant coupling between two transmission coils and two reception coils aligned on a line is used. By applying the phase difference to the two transmission coils, the power transferred to the two reception coils can be controlled. The mechanism of the proposed system is described using an equivalent circuit and the feasibility of the system is experimentally demonstrated. The maximum power transfer efficiency of 69% is obtained at the phase difference of 90 degrees where the power transfer to another reception coil is 10%.