Study on Voltage Rating Improvement of the YBCO Thin-Film Superconducting Wire its Application for the Power Apparatus

Abstract

A superconducting fault current limiter plays the role of quickly limiting the fault current when a failure occurs in an electric power system. The SF12050 YBCO thin-film superconducting wire is used as the current-limiting element of superconducting current limiters due to its high voltage rate and fast superconducting to normal conduction phase transition speed. However, SF12050 has a thin (2000-nm-thick) stabilizing layer. Therefore, it may be damaged by thermal quenches while carrying a fault current. The stabilizing layer is the part that is responsible for the thermal burdens on YBCO thin-film wires. If such thermal burdens could be reduced by improving the structure of the stabilizing layer, superconducting current limiting elements with enhanced performance could be manufactured. Thus, in this study, the thickness of the stabilizing layer of SF12050, an Ag layer, was increased to 500 nm to improve its structure using the thermal deposition method, and to verify the increases in the thermal stability and voltage rate (increased electric capacity).