Islanding Dependencies and Detection in low-Voltage grids with grid forming Inverters

Abstract

With increasing shares of distributed low-voltage renewable power generation, inadvertent islanding phenomena will occur with higher chance in the future. It is currently discussed whether grid forming inverters would further increase the chance of islanding to occur in certain scenarios. Against this background, this paper serves to give insight into islanding prerequisites and will investigate a basic model of the different physical dependencies that will exist in islands that might be created around grid supporting as well as grid forming inverters in order to highlight fundamental differences between the two islanding situations. Based upon these, possible pathways to detect and cease islanding using grid forming inverters in compliance with current grid codes are illustrated. One of these possibilities is further investigated and demonstrated in a laboratory setup.