Optimal resonance reactive current shielding design in wireless power transfer systems

Recently, Electric Vehicles (EVs) are widely used in the transportation sector, because they are offering effective solutions for environmental and energy issues. To charge EVs on the road or in the parking, wireless power transfer (WPT) technology is introduced. However, increased use of WPT chargers caused an increase of Electromagnetic field (EMF) exposure to human bodies and Electromagnetic Interference (EMI) with surrounding electronic devices. In this paper, WPT system model is briefly explained and shielding methods used in wireless power transfer systems are discussed. Reactive resonance current loop shielding method is simulated using 3D Finite Element Analysis (FEA) software to design an optimal coils radius for power links and shielding loops. The designed system can transfer up to 12 KW through large air gap of 20 cm with coil-to-coil efficiency of 97.4%. Results show that the reactive resonance current loop method is suitable for using in WPT system for charging EVs which make the charger lighter with high efficiency and low EMF level.