A strategy for protection coordination in radial distribution networks with distributed generators

In this paper, a simple and effective strategy is proposed for the coordination of protective devices in typical radial distribution networks embedding distributed generation units. The proposed strategy benefits from microprocessor-based reclosers and directional elements for feeder relays, and addresses the issues of blinding of protection, false tripping, recloserfuse and fuse-fuse miscoordination, and failed auto-reclosing. Another salient feature of the proposed strategy is that it does not require adaptive protective devices. The effectiveness of the proposed algorithm is demonstrated by simulation case studies conducted on a model of an example distribution network, in the PSCAD/EMTDC software environment. The paper also presents the steps taken to characterize the impact of DGs on the protection coordination, for host and neighboring feeders.