Abstract
Increased penetration levels of Distributed Generation (DG) causes protection related challenges on distribution systems. In this project, the issues of Relay Desensitization on a power distribution system is revisited and reconfirmed using a modified version of the IEEE 34-Node Test Feeder. Two separate programs have been used for short circuit simulations to gain a higher confidence level on the accuracy of the results. The programs are commonly used by the power systems industry and known as, Electrical Transient and Analysis Program (ETAP®) and Advanced Systems for Power Engineering (ASPEN®). Two different fault locations and four fault types are investigated at increasing DG levels. The same system with known parameters has been used as the distribution system model for all simulated cases. Simulation results for the various fault types and DG penetration levels causing relay desensitization are analyzed and discussed. The results obtained from both programs confirm that increased penetration level of DG degrades performance of the overcurrent protection by desensitizing relays at each source. A recommended solution for a specific case is presented.