A Method for Improving Relay Protection and Coordination in Distributed Generation Systems Using Automatic Circuit Reclosers

Proposed is a methodology for improving the reliability of relay protection and coordination in distributed generation (DG) systems, particularly on the medium-voltage side. The replacement of traditional fuses with automatic circuit reclosers (ACRs) equipped with microprocessor-based Intelligent Electronic Devices (IEDs) that have relay protection functions significantly enhances protection sensitivity, reduces fault clearing time, and increases operational flexibility. The analysis includes a detailed evaluation of the Coordination Time Interval (CTI) and adjustments to the sensitivity factor. Network models developed in the Electrical Transient Analyzer Program (ETAP) demonstrate improved fault response and coordination characteristics in DG networks. The proposed methodology ensures reliable protection by effectively addressing key challenges associated with the integration of DG systems, enhancing sensitivity, selectivity, and operational efficiency, making these networks more suitable for future expansion and investment.