Operating Characteristics for Different Resonance Frequency Ranges of Wireless Power Charging System in Superconducting MAGLEV Train

Our research team has developed a wireless power charging system for a high-speed superconducting magnetic levitation train based on the strong resonance coupling method to improve the transfer efficiency and stability. Especially, the range of resonance frequency is one of main key design parameters to fabricate the system since the high resonance frequency can improve the transfer distance easily. On the other hand, since the sensitivity of impedance matching between antenna and receiver coils is increased in the range of higher frequency, the technique of stable impedance matching design including elaborated rectifying subcircuit has been required to commercialize under high-power transfer applications. For this reason, the various transfer characteristics under different ranges for resonance frequency conditions should be evaluated to accomplish improve the transfer efficiency. Thus, in this paper, the transfer efficiency of the moving position of receiver (Rx) coil and consumption of liquid nitrogen were measured at 100 and 370 kHz with 250 W, respectively. In addition, the operating characteristics of the cooled copper Rx and HTS Rx coil were evaluated under 100 and 370 kHz with 250 W, respectively.