Protection for distributed energy systems

Liberalization on energy market together with trend of reducing gas emission and technical advantages of small energy sources near the load can cause more utilized of the distributed energy sources in electrical distribution system. The increasing ratio of utilizing of distributed energy sources in electrical distribution system has emerged power flow with two sides and highly variable and small short circuit currents. These results can cause challenges for coordination of electrical protection system. In this thesis, the fault characteristics of distributed energy sources are defined. Then most prevalent protection relays and switchgears for medium- low voltage level distribution systems also short circuit calculation methods are explained. Comprehensive short circuit analysis and electrical protection study are realized using ERACS and ETAP software for examples of electrical distribution systems which are comprises of different type distributed energy sources with medium or low voltage level. Finally, results are presented in a comparison table, conclusions which are reached through power system simulations are explained and anti-islanding protection system is summarized in a table.