Critical Current Degradation in HTS Tapes for Superconducting Fault Current Limiter under Repeated Overcurrent

Superconducting fault current limiters (SFCL) can be an alternative to conventional devices limiting short-circuit currents in power systems. SFCL use high-temperature superconducting tapes of the second generation (HTS 2G) SFCL, which, after reaching characteristic critical tape, go into resistive state (quenching), current. The determines moment activation SFCL. Therefore, its value should not change during operation device due repeated limitation currents. constancy is a prerequisite for proper cooperation with system protection devices. Multiple quenching cause microdamage layers responsible lowering HTS tapes. article presents research results on degradation processes 2G intended construction action prospective values exceeding tested decrease tape as result multiple transitions was investigated. amount energy emitted test pulse 0.2 s duration determined. voltage drop which does accelerated processes, were defined. microstructural tests cross-sections new subjected performed.