High-frequency electromagnetic force characteristics on electromagnetic shielding materials in wireless power transmission system

Abstract

The high frequency resonant current in coupler would inevitable results in interaction of electromagnetic force (EMF), leading to short service life, poor security and low reliability of wireless power transmission (WPT). It may be worse when electromagnetic shielding (EMS) materials are used. The mechanism and characteristics of the EMF on various EMS materials are revealed. Based on Lorentz force and Kelvin force, the mathematical calculating model of EMF is established with analysis of forces of iron, copper, aluminum, and ferrite. The effects of electric conductivity and magnetic permeability on EMF are compared. Simulation is established to verify the analysis of the high frequency EMF. The results showed that the effects of electric conductivity and magnetic permeability on the direction of the EMF are opposite. And the force can be reduced by appropriate designing the shielding structure.