Optimization of 2G YBCO Wires for Resistive Fault Current Limiters

Recent progress increasing the critical current density of second generation (2G) high temperature superconductor (HTS) tapes seems also to increase the switching capacity per effective surface area. An optimized (as thin as possible, as thick as necessary) stabilization cap layer allows to maximize the switching capacity of tapes at an acceptable temperature rise and to minimize the overall tape length. We present the architecture of available 2G HTS tapes designed for FCL, address an approximate and a precise HTS model computation under full fault and moderate overload conditions and report on the set of experiments on short tape samples for identifying the optimal stabilized coated conductor according to the required specification of an FCL with large inrush current. As a result we present a tool to optimize the Ag cap layer in dependence on critical current density and limitation time.