Fault current model for YBCO cables

Superconducting cables can be used to transport large amounts of energy with small losses in considerably smaller volume compared to conventional cables. At present, the first YBCO cable demonstrations are under development and they are expected to outperform BSCCO cables. Due to extremely high current densities in very thin superconducting films these cables are sensitive to overcurrents and therefore cable designers should be able to predict their behaviour during faults. In this paper, the temperature distribution in various 1 kA YBCO cable geometries was computed with several fault current waveforms in order to study the cable stability. FEM models were used to determine simultaneously both the current density and the temperature distributions of the cable as functions of time. Real temperature dependent properties of the cable materials and the strong magnetic field and current density dependence of the superconductor resistivity were taken into account.