Protection requirement graph for interconnection of distributed generation on distribution level

In this paper, the protection issues related to distributed generation in distribution networks are considered. Especially, the requirements for the generation unit's protection are discussed. A new graphical approach is used for finding the unambiguous limits of operation. The method is based on using present network planning systems applied widely among network companies. The features and constraints of these systems are considered. The protection planning and coordination are also discussed in a wider aspect. The method proposed is applied in an example case using actual network data.