Recloser – Fuse Coordination on Rural Feeders Having Distributed Generation by Using Specific Energy

The integration of Distributed Energy Resources (DER) implies a major challenge for the protection of the distribution network, where the origin of the energy and its direction was known. The DER can change the direction and shape of the fault current, and in the protection system can cause selectivity failures. Particularly, coordination among reclosers, sectionalizers, and fuses is affected, with possible loss of coordination. Selectivity of a typical protection system is studied, using time-current methodology, and the "specific energy versus time" as an additional tool. The advantage of coordination through this methodology is that the protection is immune to fault current variability, allowing coordination between micro-processed devices and fuses. Modeled example is presented using MatLab Simulink, simulating a typical feeders. It is concluded that the incorporation of the specific-energy in the coordination studies, provide a powerful tool allowing the analysis of the coexistence of modern micro-processed protections with traditional ones.