Analysis on current limiting characteristics of a flux-lock type SFCL with two triggering current levels

Abstract

In this paper, the flux-lock type superconducting fault current limiter (SFCL) with two triggering current levels was suggested and its current limiting characteristics were analyzed. The structure of the suggested flux-lock type SFCL with two triggering current levels largely consists of two parts. One is the flux-lock type SFCL with two magnetically coupled coils with series or parallel connection and one high-T(C) superconducting (HTSC) element, which is connected in series or parallel with one of two coils. The other is constructed in the third coil with another HTSC element. This suggested flux-lock type SFCL can limit the fault current by generating its limiting impedance with two different amplitudes, which are dependent on the initial amplitude of the fault current in case of the fault occurrence. To confirm the usefulness of the proposed SFCL, the limiting tests of the SFCL according to the fault angle, which is one of the effective fault conditions to affect the amplitude of the initial fault current, were carried out and its effective limiting operations were discussed. (C) 2011 Elsevier B.V. All rights reserved.