Overcurrent Protection Coordination in a Power Distribution Network With the Active Superconductive Fault Current Limiter

The active saturated iron-core superconducting fault current limiter (SISFCL) is one of the best solutions to coping with high fault current levels and may be helpful in building future smart distribution networks. The application of an SISFCL in a distribution system can reduce the fault current to an acceptable level when a short-circuit fault occurs at different positions. The operational principle and the current-limiting characteristic of an active SISFCL are briefly introduced in this paper. The influence of an active SISFCL on the conventional inverse and definite time-delay overcurrent protective relays is discussed. In order to maintain reliable operation of the distribution system with an SISFCL, the protection coordination and setting solution is proposed. A model of a real 35-kV distribution system with an active SISFCL was built and simulated with the Electro-Magnetic Transients Program including DC software. Simulation tests have demonstrated the correctness and validity of theoretical analyses.