차폐 소재에 따른 초전도 공진 코일의 무선전력전송 특성

Abstract

Wireless power transmission is a new promising technology that transmits power without wires by using the free space as a medium. The wireless power transmission based on the magnetic resonance uses the resonance between the transmitter and receiver coils. Accordingly, it can address the issues including the degree of freedom and transmission distance, which are the problems of the conventional methods. However, the quality factor of the coil must be kept high to improve the transmission efficiency of the magnetic resonance wireless power transmission system. A high quality factor of the coil can increase the transmission efficiency even when the degree of magnetic coupling decreases. Therefore, a superconductor coil was applied to improve the transmission efficiency of the magnetic resonance wireless power transmission system. In the preceding study, the efficiency of the magnetic resonance wireless power transmission system with the superconductor resonance coil was verified. However, the transmission efficiency of transmitter and receiver coils is affected by the electromagnetic wave interference signals or noises due to the surrounding shielding materials. Therefore, the wireless power transmission characteristics should be studied in relation to the surrounding shielding materials to ensure the reliability and economic feasibility. In this study, shielding materials were used for a superconductor wireless power transmission system. The shielding materials included bakelite, FRP, PVC plastic, polystyrene, iron, and aluminum. In addition, single, housing shielding materials were used between the transmitter and receiver coils. Then the S-parameter, Smith chart, and e-field of the superconductor resonance coils were comparatively analyzed. The results showed that the bakelite and FRP improved the wireless power transmission characteristics. It is expected that a system or a cooling container based on the results of this study will be able to ensure the practical wireless power transmission systems with superconductor coils.