Electrical and Thermal Behaviour of High Temperature Superconductors for SFCL Applications

Abstract

The aim of this study is to experimentally determine the thermal and electrical properties of a 2G HTS tape to be used in construction of a Superconducting Fault Current Limiter (SFCL). Minimum HTS tape length required for different source voltage and current ratings for safe operations during fault conditions were determined. Three different mechanical frames for Fault Current Limiter (FCL) applications were designed for three configurations of SFCL. Two different experiments were conducted using one of the mechanical frames. The first experiment was conducted to determine the voltage vs. current characteristics of the HTS wire. Subsequently the value of critical current of the tape was determined. The variation of resistance of copper joint with respect to current was also determined. The second experiment recorded both the voltage and temperature of the HTS tape at different values of current. Four different trials were conducted in which temperature and corresponding voltage characteristics were correlated. In both the cases direct current was used. Different values of critical current were found when the current was being ramped up and when the current was being ramped down. The temperature of the tape was then allowed to rise until the tape got burnt.