Design Considerations of Cooling Vessel to Improve Power Charging under Magnetic Shielding Structure in Wireless Power Charging System in Magnetic Levitation Train

Abstract

The wireless power transfer (WPT) using magnetic resonance coupling method has been known to have the advantage of being able to transfer power across large air gap with considerably high efficiency. As well as, as such a method can eliminate the physical contact loss in the system, it provides an ideal solution for the problem of contact losses in the power applications. From these reasons, WPT technology has started to be applied to the wireless charging for various power applications such as transportations (train, underwater ship, electric vehicle). In the high speed superconducting magnetic levitation (MAGLEV) train, antenna (Tx) coils, which are installed both sides of train, are placed on the guidance rail, as well as, superconducting receiver (Rx) coils can be installed in traveling train. In the superconducting system, a cooling vessel, which is made by steel materials, is a requisite subsystem. However, since the steel materials can shield electromagnetic field, the structure design of cooling vessel can affect the transfer efficiency. In this study, we presented transfer efficiency and operating characteristics from copper Tx to superconducting Rx coil under different structures of cooling vessel with radio frequency power of 370 ㎑ below 500 W.