Keywords: power grids, complex networks, cascading failures, centrality measures, flow redistribution, tolerance parameters, grid vulnerability, critical infrastructures, network security, power transfer distribution factor, PTDF, European high voltage grid
Context–independent centrality measures underestimate the vulnerability of power grids
Power grids vulnerability is a key issue in society. A component failure may trigger cascades of failures across the grid and lead to a large blackout. Within complex network analysis, structural vulnerabilities of power grids have been studied mostly using purely topological approaches, which assumes that flow of power is dictated by shortest paths. However, this fails to capture the real flow characteristics of power grids. We have proposed a flow redistribution mechanism that closely mimics the flow in power grids using the power transfer distribution factor (PTDF). We apply the model to the European high–voltage grid to carry out a comparative study for a number of centrality measures. 'Centrality' gives an indication of the criticality of network components. We also show a brief comparison of the end results with other power grid systems to generalise the result.