Operating characteristics and cooling cost evaluation for HTS receiver arrays of wireless power charging system in superconducting MAGLEV train

Since conventional power supply unit should be attached to HTS magnet in the MAGLEV, a large thermal loss is indispensably caused by power transfer wires and joints, those have been one of essential obstacles in the superconducting MAGLEV train. As the wireless power transfer (WPT) technology based on strongly resonance coupled method realizes large power charging without any wires through the air, there are advantages compared with the wired counterparts, such as convenient, safety and fearless transmission of power during movement. Above all, the WPT technology in the MAGLEV can reduce the cost of tunnel construction since the space of conventional power line doesn't required. From these merits, the WPT systems have been started to be applied to the wireless charging for various power applications such as transportations (train, underwater ship, electric vehicle). In this study, as a practical approach, authors investigate transfer efficiency and cooling cost for multi-Tx and multi-sized single Tx coils under different size of Rx coils arrays, respectively. Additionally, authors investigated transfer ratio at HTS Rx with helix and spiral Tx coils under different interval. As well as, authors evaluate cooling cost of different sizes of HTS receiver under long single and multi-copper antenna arrays based on nitrogen evaporation method.