Method, impact and rank similarity of modified centrality measures of power grid to identify critical components

Modified versions of betweenness and closeness centrality measures are proposed to identify and rank critical nodes in power systems. Power flows in various lines of a transmission system are taken as weighting parameters to calculate betweenness and closeness centrality measures. Changes in measures of impact like path length, connectivity loss and size of blackout are observed when nodes from the nominal system are removed one by one. Test results show the efficacy of proposed modified method because of severe effect found on measures of impact. Rank similarity analysis is carried out on Australian test system in six different operating conditions to validate that critical nodes do not change the order of criticality even though system loads and generations are varied in a wide range.