Overcurrent protection issues for radial distribution systems with distributed generators

The integration of distributed generators (DGs) into distribution systems is being proposed as a solution to meet increasing load demands and to utilize more renewable energy. Existing overprotection schemes must be modified to address the new system characteristics of radial distribution systems with DGs. Minimum ldquooff-the-shelfrdquo overcurrent protection devices and distributed generators were added to the 123 Nodes Radial Test feeder. A commercial power systems analysis tool was used to determine the coordination issues that arise in the distribution system due to the integration of DGs. The results of these studies are presented and discussed.