The Research Of Complex Network Theory In Electricity Network

In recent years, with the development of construction of UHV and the large-scale interconnection within power grids, the system operation uncertainty increased caused by grid interconnection and the risk of a wide range of chain failure has been widespread concerned. The mechanism and the inherent characteristics of the blackout, as well as how to be effective in preventing large-scale blackouts, became the focus of the current domestic and international experts and scholars to study and research. Complex power systems presented complexity, uncertainty and unpredictability in time and space. It is difficult to analyze the mechanism of power grid of cascading failures only by traditional reductionism. The complex network theory has provided a new way of thinking and theoretical methods for the analysis of characteristics of blackout caused by cascading failures and the overall characteristics of large-scale interconnected power network, helping researchers to analyze the failure mechanism from macro level.Based on complex network theory, the paper analyzes the characteristics of cascading failure process and its blackout, which under the different operating status and network topology evolution. Also, it shows the vision of the application of complex network theory in power system analysis in the future. The specific work of this paper is as follows:Firstly, the paper summarized the background and significance of the topic and introduced the development of the research of cascading failures and research status in China and in foreign countries, pointing out that it has great scientific theory value and practical significance.Secondly, the paper introduced basic parameters and topology analysis models commonly used in complex network theory. Based on complex network theory, the paper modeled the actual grid topology and analyzed the degree distribution characteristics of actual grid topology.Thirdly, the paper introduced the principle of self-organized criticality theory and statistical analysis between the power system blackouts and self-organized criticality. It has analyzed the three key factors which influence the power system self-organized criticality and introduced commonly used cascade models to study the self-organized criticality.Fourthly, based on the OPA model and concerned with the evolution of structure, the paper has constructed an improved model. Using the MATLAB simulation software, it has analyzed the influence of average load rate and network topology characteristics. Simulation results show that, by different evolution methods, when the average load rate is small, the possibility of blackout by the scale-free evolution method is lower than the possibility of blackout by the small world evolution method. When the average load rate is large, the possibility of blackout of two methods is almost the same. In addition, if the Clustering Coefficient of two networks are almost the same, the smaller Characteristic Length, the bigger blackout. While if the Characteristic Length of two networks is almost the same, the bigger Clustering Coefficient, the bigger possibility of blackout.