Testing and modelling of inductive superconducting fault current limiters

Fault current limiters are expected to be amongst the first applications of high-temperature superconductors in power engineering. The use of the intrinsic property of a superconductor to transit from a zero (or near zero in the case of AC currents) resistance state to a highly resistive state when the critical current is exceeded is the basis for a fast acting fault current limiter. In this article, the authors report test results (43 kVA nominal power: 450 V RMS and 95 A RMS) and comparisons to theoretical simulations. Circuit analysis is used to study design issues and to extract the superconducting material's (BSCCO 2212) properties during the application of the short-circuit. EMTP simulation is employed to predict fault current limiter behaviour in the utility network in order to coordinate with other equipment.