Vulnerability analysis of the US power grid based on local load-redistribution

• A new networked model is given to study the vulnerability of the US power grid.
• The similarities and differences of three models are compared in this paper.
• Several imprecise and illogical results of the existing literatures are found in this paper.
• The infimum of tolerate parameter is proposed to discuss the characteristics of the power grid.
• The presented model can decrease the risk of power grid subjected to failures.

In this paper, local load-redistribution is employed to study the vulnerability of the US power grid subjected to attacks, and the initial load of power node is assumed as the linear summation of its degree and the sum of its neighbors’ degrees. Based on the simulation results, we find that with the decrease of the initial load of power node, the critical threshold of tolerance parameter increases subjected to the highest load node-based attack, but the critical threshold decreases subjected to the lowest load node-based attacks. Meanwhile, we discover that the critical threshold subjected to the lowest load node-based attack is larger than that subjected to the highest load node-based attack when the tunable parameter α ∈ [0.1, 0.9]. Moreover, this paper compares the new model with the other two existing models, and the results illustrate that there are many similarities between these two existing models, but they are different from the new model presented in this paper. Furthermore, the infimum of tolerance parameter is proposed to portray the minimum cost of power grid, which can give a method to construct more robust power grids in the future.