Fundamental Characteristics of Y123 thin film for switching surge current to design SCFCL

Superconducting Fault Current Limiters (SC-FCLs) have been expected not only to reduce fault current but also to improve power system stability. For introducing them, various kinds of characteristics, such as trigger current level, must be examined. They should be designed not to be triggered by switching surge that comes from out of the target section. In this paper, fundamental characteristics of SCFCL for surge current have been studied. Y123 thin films with Au protection layer on sapphire substrate have been prepared, and the voltage-current characteristics have been measured. The measurements have been carried out by use of the impulse and sinusoidal currents to evaluate the characteristics of Y123 thin film for switching surge. The relation between operational current levels and their operational times and the relation between operational current levels and the wave front times are shown in the paper. These characteristics are useful for designing the SCFCL which will not to be triggered by switching surge.