Investigations into the operation of an existing medium-voltage distribution feeder as a microgrid

This paper studies a realistic utility distribution network that embeds distributed energy resources. The objectives are (1) to propose the apparatus and controls that enable the network to operate in isolation from the host power system, and (2) to propose a practical and simple protection strategy that is effective in both the grid-connected mode and the islanded mode. The effectiveness of the proposed control and protection strategies is demonstrated through simulation studies, conducted in the PSCAD/EMTDC software environment.