Test results and analysis of current limiting characteristics in conduction cooled Bi2223 fault current limiter

Current limiting characteristics in conduction cooled high-T_c superconducting fault current limiter (SFCL) have been calculated numerically. These calculations have been performed based on the measured results of the E-J characteristics in the region of I_c to several tens of I_c. With decreasing operating temperature of the SFCL, the current limiting characteristics are improved, especially at the first peak after the fault, in addition to the decrease of the required volume of superconductor. The improvement is caused by the high resistance of superconductor associated with the reduction of cross-sectional area and the discrepancy of E-J characteristics between different temperatures of superconductor in the high electric field region. Such improvement of current limiting characteristics has been observed in the experiment using a small model of conduction cooled SFCL.