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

A new superconducting fault current limiter (SFCL) using DC biased saturated core have been proposed in this paper. All existing saturated core SFCL are AC type. The proposed SFCL is a DC reactor type where all the windings carry DC current. The B-H curve of a magnetic circuit shows that less inductance value can be achieved in saturated region and very high value in unsaturated region. The reactance window between the saturated and unsaturated region depends on magnetic material, core size and its biasing conditions. The proposed type of SFCL can be designed efficiently taking the full advantage 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 time. On the other hand, the existing DC reactor (bridge) type SFCL shows a fixed value of inductance both in normal and fault time. Some simulation results are presented here to show the performance of the proposed SFCL. (C) 2001 Elsevier Science Ltd. All rights reserved.