Protection Coordination Index Enhancement Considering Multiple DG Locations Using FCL

Increasing the penetration level of distributed generation (DG) may lead to improper protection coordination. Previous work introduced a protection coordination index (PCI) that can quantify the impact of installing a DG at individual locations. This paper extends on previous work and proposes a generalized approach for calculating PCI considering multiple DG locations simultaneously. Furthermore, this paper proposes a solution for enhancing the PCI using fault current limiters (FCL). The problem is formulated as a mixed-integer nonlinear programming problem to determine the optimal FCL size and location as well as enhanced PCI.