Recovery Characteristic of Coated Conductors for Superconducting Fault Current Limiters

Superconducting fault current limiters (SFCL) offer the possibility to reduce the level of short circuit currents in electrical power distribution networks. During the current limitation, the temperature of the superconductor increases because of the resistive losses until the short circuit is switched off. After the current limitation, the superconductor has to cool down to become superconducting again. If recovery under load is required, the superconductor has to cool down under regular load conditions. This paper presents experimental recovery under load tests of coated conductors for the use in fault current limiters or combined applications, like fault current limiting transformers. The results show the limits of the recovery time, depending on the residual current for different coated conductors in boiling liquid nitrogen.