Evaluation of power system robustness in order to prevent cascading outages

Abstract

Power system robustness against overload condition is a challenging issue in the fields of power systemplanning and operation. In this paper, two indices are proposed to evaluate power system robustness. The proposedindices are used to identify critical lines whose failure is due to overload, leading the power system to cascading outagesand blackout. The first proposed index is a linear index. The second index is based on graph theory metrics. To preventcascading outages, system robustness is calculated for all N − 1 and N − 2 contingencies. The lines whose outageslead to the smallest robustness values are considered as critical lines. The proposed indices are validated by applying tothe IEEE 118-bus test system. Simulation results demonstrate the capability of both indices in identifying critical lines.Therefore, the purposed indices could be used as a reliable metric to apply preventive actions against possible cascadingoutages and blackouts.