Positive Research On The Western Power Grid Of The United States Based On Complex Networks

It is now universally acknowledged that complex network is a novel and efficient tool for characterizing and studying various complex structures in both nature and society. At present, scientists have already done much research on lots of networks. For example, communication networks, computer networks, neuronal networks, social networks, scientific-collaboration networks, ecological networks, traffic networks, and so on.Based on complex network theory, this thesis conducted an empirical research on the western power grid of the United States by using complex network analysis tools Pajek, including topological structure analysis and invulnerability analysis.First, a detailed analysis of the power network topology of the western United States was given; then some important parameters were obtained, such as the degree of power network and the cumulative distribution, the betweenness centrality and cumulative betweenness centrality distribution, clustering coefficient, average degree, the average length of the shortest path, the maximum connected region, closeness centrality and tenacity. The results validate the small world characteristics of the western power grid of U.S.A.. Finally, the small-world characteristics of the electric power network and its effect on cascading failure are qualitatively analyzed.In the invulnerability analysis, four integrative attack strategies of degree, betweenness centrality, core and closeness centrality were presented based on the evaluation of the invulnerability of topological structure with the western power grid of U.S.A. from the perspectives of the maximum connected region, shortest path length, clustering coefficient and new criterion-tenacity. Finally, the invulnerability of small-world networks such as the western power grid of U.S.A. was obtained. The result shows that the strategy based on the betweenness centrality (CB) is the most fragile, followed by the strategy based on closeness centrality (CCs), then the strategy based on the degree (CD), and finally the strategy based on the core (CC). A scale-free network model was constructed by using the four proposed aggressive strategies to attack and survivability assessment. Eventually the scale-free network was proposed based on the survivability of the strategy, with the descending order of the reflected fragility being: the strategy based on the betweenness centrality's attack (CB) > the strategy based on the closeness centrality's attack (CCs) > the strategy based on the core's attack (CC) > the strategy based on the degree's attack (CD).