Methods for Assessing the Protection Impacts of Distributed Generation in Network Planning Activities

The increasing amount of distributed generation (DG) located on distribution level is affecting the usage of the power system in different ways. The traditional planning and control schemes may become inoperative due to the contribution of DG. As the impacts of DG are significant and they are increasing rapidly, they should be better included in the planning systems and methods applied. Instead of performing only case studies during the DG interconnection process, the impacts of DG should be integrated in all network calculation routines, as they truly influence every power flow or fault current calculation, for instance. This paper discusses the problems and possibilities related to studying the protection impacts of DG in general-level planning systems. The aspect of distribution network operator (DNO) has been applied.