Evaluating the reliability of islanded microgrid in an emergency mode

Microgrid can be operating independently during the period from grid-connected to grid-off, especially in an emergency mode. As the islanded microgrid is generally run in a short time, traditional power system reliability analysis has limitations to this point. A new approach based on fault tree analysis (FTA) to evaluate the reliability of islanded microgrid with the specific operation time is presented. The modeling and analysis is performed on a benchmark 0.4 kV low voltage microgrid network. The results include the outage probability for each of the consumers, the unreliability of microgrid network, and the measures of importance for microgrid and each consumer, which can identify the variation of the level of reliability under the specific operation time and weakest parts contributing most to unreliability. The results show that the developed technique can be applied to evaluate the reliability of islanded microgrid in an emergency mode.