A proposal of emergency microgrid operation of distribution systems after large scale disasters

This paper proposes a new strategy which makes modern electric power systems more resilient against large disasters, and shows new analysis methods for the optimum operation of the resilient power systems. The strategy is based on islanding operation of healthy distribution networks by using a lot of small distributed generators (DGs) such as photovoltaic generators (PVs), fuel cells, batteries and electric vehicles (EVs). In order to make the islanding operation technically feasible, one of the developed analysis methods is the optimal power flow (OPF) analysis to find the discharge power from EVs which minimizes distribution network loss. The other one is the imbalanced power flow analysis to find an optimal allocation of DGs in an islanded distribution network from the viewpoint of reducing voltage imbalance.