Study on Reason of Destruction in YBCO Thin Film during Current Limiting and Improvement of the Performance in Current Limiting

Abstract

We have performed fault current limiting test using YBCO thin film and investigated reason of the destruction during current limiting. Destruction phenomena of the film are two patterns. One occurred immediately after current limiting and the other one occurred during current limiting. In a phenomena of destruction, quench propagation velocity almost doesn't change as against increases of energy consumption per unit time, energy consumption per unit area increases as energy consumption per unit time increases. Therefore, local part of the film reaches dissolution temperature and arc occurres.
As a result, it is considered that the performance of the film is improved by decreasing energy consumption per unit time. Thus, we connected parallel capacitor to the film for limiting energy consumption per unit time. Consequently, the performance of the film in current limiting will be improved.