Power system vulnerability analysis - towards validation of centrality measures

Threat assessments play a key role in determining appropriate mitigation strategies to counter credible threats to the power system. In order to further understand the capability of a malicious agent to coordinate an attack on the power grid given limited system information, graph theory based centrality measures are utilized for power systems vulnerability analysis. Results are compared to vulnerability analysis indices utilizing DC power flow based linear sensitivity factors with complete power system information. Correlations of centrality and linear sensitivity factor based vulnerability rankings are performed, and matched pair comparisons of top rankings are presented using the nonparametric Wilcoxon signed rank statistical test. Evidence is presented in support of the edge betweeness centrality measure in determining sensitive line outages based solely on the branch impedance values of a power system. Results obtained for four different test case systems indicate the threat potential of a system attack planned from limited topology information.