Microgrid black-start after natural disaster with load restoration using spanning tree search

One solution towards a resilient electric distribution system during extreme weather conditions and other natural disasters is microgrid with distribution automation. This low voltage bottom-up black start capability and feeder reconfiguration capability allow true realization of the full potentialities of distributed generation. This paper exploits the black start of a low voltage network supported by automatic sectionalization of microgrids. The loads are restored based on their criticality. The islanded or unserved critical loads are then picked up by the microgrids using spanning tree search that accommodates multiple faults. Unbalanced three phase power flow is performed to ensure all operational constraints have been satisfied. The simulation result is based on a modified IEEE 37-node system with dispersed distributed generation. The study validates the feasibility of the proposed approach.