Proposal of saturated DC reactor type superconducting fault current limiter (SFCL)

A new superconducting fault current limiter (SFCL) using DC biased saturate d core have been proposed in this paper. All existing saturated core SFCL a re AC type. The proposed SFCL is a DC reactor type where all the windings c arry DC current. The B-H curve of a magnetic circuit shows that less induct ance value can be achieved in saturated region and very high value in unsat urated region. The reactance window between the saturated and unsaturated r egion depends on magnetic material, core size and its biasing conditions. T he proposed type of SFCL can be designed efficiently taking the full advant age of the reactance window in current limiting mode. The advantage of this type of SFCL over the existing DC reactor type is that, it shows very low value of inductance at normal operation and very high value during fault ti me. On the other hand, the existing DC reactor (bridge) type SFCL shows a f ixed value of inductance both in normal and fault time. Some simulation res ults are presented here to show the performance of the proposed SFCL. (C) 2 001 Elsevier Science Ltd. All rights reserved.