Impact of Distributed Generators on Protective Devices in Radial Distribution Systems

Proper protection of distribution systems is essential to ensure high reliability and power quality. With the proposed migration to the inclusion of distributed generation in distribution systems, it is critical that the protection schemes be adapted to address these new and very different system characteristics. The authors of this paper have studied the impact of the integration of DGs in radial distribution systems on the selectivity and coordination of existing overcurrent protection schemes. Studies were conducted using the IEEE 34 node test feeder. Protective devices and distributed generators were added to the test feeder. Normal and short circuit characteristics of the feeder with and without distributed generators were analyzed. The analysis is being used to determine how overcurrent protection must be modified to properly protect distribution systems with DGs. This presentation discusses the findings of these studies