Determination of Optimal Current Phase Difference between Transmitter and Receiver Coils for Minimizing Leakage Magnetic Field in Wireless Power Transfer Systems

This paper proposes a method for determining the optimal phase difference between transmitter and receiver coils for suppressing leakage magnetic field in wireless power transfer (WPT) systems. As the power level of WPT systems increases, the leakage in the magnetic field also increases. As a result, the possibility of electromagnetic field (EMF) or electromagnetic interference (EMI) issues also increases. There are various shielding methods for reducing leakage magnetic field, but all the methods need additional materials or power sources. In contrast, the proposed method can suppress leakage magnetic field by determining the phase difference between TX and RX coils current without additional materials. So, the proposed method also can reduce the weight and cost of the WPT systems.