Protection Coordination with High Penetration of Solar Power to Distribution Networks

High penetration of renewable power generation to radial distribution networks (RDNs) is a threat to proper protection coordination of overcurrent protection scheme. Bidirectional power flow and rise in short-circuit currents are the two major factors affecting the existing protection schemes. Additionally, the reconfigurable ability of modern RDNs further complicates protection coordination. In this paper, the impact on protection coordination of directional overcurrent relays (DOCRs) because of the high penetration of solar photovoltaic (PV) power to RDNs has been analyzed, and suitable protection settings have been proposed. Also, feeder reconfiguration has been considered in the presented settings of DOCRs. This protection scheme has been validated on a real existing reconfigurable RDN on the campus of the Indian Institute of Technology Kanpur. Also, recommendations have been presented for proper protection coordination in the presence of high penetration of PV system and feeder reconfiguration.