Design and Analysis of Double-Eight Shaped Shielding Coil for Solenoid Coil in Loosely-Coupled Wireless Power Transfer System

In this paper, we propose and analyze an double-eight shielding coil for a solenoid coil in loosely-coupled wireless power transfer (WPT) system. We suggest the shielding coil to get lower level of electromagnetic field (EMF) for the solenoid coil. The proposed double-eight shaped shielding coil, which are placed beside a transmitter (Tx) coil. The shielding coil is used to confine the leakage magnetic flux from the Tx coil and reduce the EMF. Furthermore, in the WPT system with the shielding coil, the equation of the resonant frequency condition is derived from the equivalent circuit. Using the proposed shielding coil, we reduced the EMF level by 9.3 dB scale.