Fundamentals of detectability and detection methods of unintentional electrical islands

The appearance of unintentional islanding in electrical grids has become a serious challenge due to the increasing number of distributed generation (DG). However, the elementary processes during the occurrence of an island are still not well known. Therefore, this paper introduces a study of the analytical basics, to understand the formation of unintentional islands. Furthermore, simulations are presented which consider the influence of the load and the type of DG on the transient behavior during the islanding. A graphical depiction for the reaction of the islanding protection system is shown. The diagrams are used to derive statements about the stability of unintentional islands.