Current limiting characteristics of transformer type superconducting fault current limiter with shunt impedance and inductive load

The superconducting fault current limiters have been expected as a possible type of power apparatus to reduce the fault current in the power system. The transformer type superconducting fault current limiter, which consists of a series transformer and a superconducting current limiting device, is one type of the superconducting fault current limiter. In this paper, the influences of the load power factor on the current limiting characteristics are analyzed. The analyses are carried out based on per unit system, and the differences of the current limiting characteristics caused by different shunt impedances (inductive and resistive shunt) are also discussed. The transient performance considering the magnetic saturation is also analyzed, and it is turned out that the inductive shunt is more effective to reduce the peak of the transmission line fault current. The experimental results obtained by using a 5 kVA-class experimental fault current limiter are shown to justify the analyses.