LAUSR

The results of tests of a short-circuit resistive switching superconducting fault current limiter (SFCL) for dc mains with maximum voltage of 4.1 kV and rated current of 4 kA have been considered. The superconducting unit and automatic high-speed vacuum breaker are key components of the SFCL. The superconducting unit consists of eight series-parallel connected modules, each of which contains four parallel high-temperature superconducting (HTSC) tapes. The tests of the SFCL have been carried out under simulations of short-circuit current with maximum current of 20 kA (maximum rate of current rise is 2500 A/ms) at a voltage of 4 kV. The tests have shown the ability of SFCL to limit the current up to 4 kA and turn it off 5 ms after the starting the mode of current limitation. The mean temperature of a HTSC tape reached up to 190 K at a duration of current limitation of 5 ms, which is in the range of allowed temperatures (lower than 290 K). The time to restore superconductivity of SFCL after turning off the current was no higher than 0.3 s.