Optimized shield design for reduction of EMF from wireless power transfer systems

In this paper, we proposed an optimized shield design for electromagnetic field (EMF) reduction from the wireless power transfer (WPT) system. Three different cases of shield design are examined in terms of strength of EMF and mutual inductance, which is directly related to power transfer efficiency. Analysis results show that when using both ferrite and conducting sheets as a shield for transmitter and receiver coils, a leakage magnetic field can be significantly reduced with negligible change in mutual inductance. Additionally, the effects of the conducting sheet's size and thickness on the EMF and the mutual inductance are also examined. Our investigation will be helpful to engineers designing modern WPT systems.