Effects of Distributed Generation on Overcurrent Relay Coordination and an Adaptive Protection Scheme

[摘要] Integration of distributed generation (DG) such as renewable energy sources to electrical network becomes more prevalent in recent years. Grid connection of DG has effects on load flow directions, voltage profile, short circuit power and especially protection selectivity. Applying traditional overcurrent protection scheme is inconvenient when system reliability and sustainability are considered. If a fault happens in DG connected network, short circuit contribution of DG, creates additional branch element feeding the fault current; compels to consider directional overcurrent (OC) protection scheme. Protection coordination might get lost for changing working conditions when DG sources are connected. Directional overcurrent relay parameters are determined for downstream and upstream relays when different combinations of DG connected singular or plural, on radial test system. With the help of proposed flow chart, relay parameters are updated and coordination between relays kept sustained for different working conditions in DigSILENT PowerFactory program.

[发布机构] Faculty of Engineering (B), Department of Electrical Engineering, Kocaeli University, Umuttepe Campus, Kocaeli; 41380, Turkey^1

[效力级别] 经济学

[关键词] Adaptive protection schemes;DIgSILENT PowerFactory;Directional over-current relays;Overcurrent relay coordination;Protection coordination;Protection selectivity;Renewable energy source;Short-circuit power