Operational control and protection implications of fault current limitation in distribution networks

Rising short-circuit fault current levels is one of the problems associated with the increased presence of distributed generation (DG) in electrical networks. A fault level management system involving superconducting fault current limiters (SCFCLs) is a potential solution to this issue. The typical applications of SCFCLs and their advantages over traditional fault current limitation measures are discussed. However, several technical issues remain, relating to: SCFCL post-fault recovery time; network control and protection; and maloperation of the SCFCL due to non-fault transient currents, such as transformer inrush. Initial solutions to these problems, involving a distributed software-based fault level management system, are presented.