Application of the Superconductor Coil for the Improvement of Wireless Power Transmission Using Magnetic Resonance

In wireless power transmission (WPT), the magnetic induction method has recently led the commercialization of wireless power chargers for mobile devices, wireless electric toothbrushes, etc. So, studies have been continuously followed in various fields. However, WPT systems needed improvements in transmission distance and efficiency to expand the application range. To solve this problem, a magnetic resonance method has been introduced. Magnetic resonance has improved the transmission distance and efficiency of WPT. In this paper, a superconductor was applied to a transmission coil to enhance its WPT efficiency using magnetic resonance. The existing normal conductor coils could be optimized by changing the coil sizes and winding methods, but the improvement of the efficiency of WPT was limited. The superconductor coil had the characteristics of 0 resistance at the critical temperature. Moreover, as the volume of the current density increased more than 100 compared with the existing copper coils, the maximum resonance characteristics could be induced when the impedances matched. The results confirmed that the WPT of the superconducting coil using magnetic resonance was more efficient than that of the conventional copper coils.