Analysis of Wireless Power Transmission Characteristics for High-Efficiency Resonant Coils

A wireless power transfer (WPT) method using superconductors was previously proposed (I. S. Jeong et. al., 2013). Subsequently, the research team proposes superconducting WPT technology for electric vehicle (EV) application. The technology is designed to maximize efficiency by applying a superconductor to the transmission and reception resonant coils. The efficiency of wireless power transmission is determined by numerous variables, including the magnetic flux, the inductance of the resonant coil, and the mutual inductance. Therefore, it is possible to increase the efficiency by changing the shape of the resonant coil. In this paper, a spiral-type coil with a laminated structure was applied as a resonant coil for wireless power transmission for EV. This can increase the efficiency by generating a greater amount of magnetic flux than the single-layer spiral coil. In addition, a high coupling coefficient (K) and Q-factor can be obtained by applying a superconductor to the resonant coil. As a result, it is possible to implement wireless power transmission with higher efficiency than the conventional wireless power transmission methods. Simulation analysis was performed using High-Frequency Structure Simulation (HFSS), an electromagnetic field analysis program.