An Introduction to Active Distribution Networks Islanding Issues

Nowadays distributed generation (DG) is of main concern due to growing power demand. Dueto increasing DG penetration, the incorporation of DGs into existing system and their independentoperation as power islands needs to be addressed properly in standard and practical workrecommendations. This paper generally introduces the chief issues in unintentional islanding and itsprohibition by the standard. Furthermore, it presents examples showing feasibility of stable and reliableintentional islanding. Accordingly, the concept of islanding detection as a requirement for either preplannedislanding operation or unplanned-islanding-prohibition, is introduced. Considering theaforementioned prohibition and the validation of feasible successful islanding operation, this paperconcludes that, in order to avoid unnecessary loss of generation specially for sensitive and high priorityloads, if we are going to establish regulations, we must take into account electric power systems facilityclassifications and variety of possible events that may result in islanding.

Keywords:

Active distribution networks , distributed generation , islanding , islanding detection , micro grids micro-grid protection and control , stand-alone operation