Load distribution vector based attack strategies against power grid systems

Security issues in complex systems such as power grid, communication network, Internet, among others have attracted wide attention from academic, government and industry. In this paper, we investigate the vulnerabilities of power grid under a topology-based network model in the context of cascading failures caused by physical attacks against substations and transmission lines. In particular, we develop attack strategies from the attackers´ points of view, aiming to cause severe damage to the network efficiency, as a way to revealing the vulnerability of the system. We propose a new and useful metric, load distribution vector (LDV), to describe the properties of nodes and links. Based on the LDV, we develop a multi-node attack strategy and a multi-link attack strategy, which are proved to be stronger attacks than the traditional load-based attacks using the Western North American power grid data. For example, the removal of only three critical nodes in the grid can reduce more than 30% of the original network efficiency, and the removal of only three critical links can reduce the network efficiency by 23%. In the above cases, the traditional load-based schemes reduce the network efficiency by 23.57% and 18.35%, respectively.