The Analysis Of Power System Cascading Failure Based On Complex Network Theory

With the rapid development of global economy, the size of power grid becomesmore and more large, grid interconnection becomes a large scale power system. Theinterconnection of power grid could improve the efficiency of system but alsoincrease the complexity of power grid, which leads to the wider spread and moreserious loss after failure. The frequent occurrence of blackouts arouses the attentionof the experts and scholars at home and abroad who care about the problems oncascading failure. The traditional analysis method can’t reveal the wholecharacteristics of system. The development of complex network theory provides anew perspective for the study of cascading failure, and theory of the whole analysismethod can analyze the global nature of the cascading failure.The large scale grid cascading failures is studied base on the theory of complexnetwork in this paper. Firstly establish a complex network model of the power grid,through the identification of weak lines in the system, then simulat the cascadingfailures. The classic model of complex network and complex network parametersoften used in power system were introduced, complex network model applied in thispaper was studied in detail and the complexity of the power system was analyzed.Then, an undirected and weighted model of the power grid was established based onthe principle of modeling power grid, the comprehensive weighted index with thereactance of lines and line capacity was proposed. Line capacity betweenness wasused to identify the vulnerable lines of power grid, the algorithm of identifyingvulnerable lines was given, and the application of the IEEE39node system proved thevalidity of the identification method.Finally, line dynamic model was used as the simulation model for cascadingfailure simulation based on the original node dynamic model. Through the percentagedrop of network efficiency to measure influence on transmission capacity of network after failure, two kinds of failure mode were applied to the analysis of cascadingfailure of power grid, and a detailed algorithm process was given. The IEEE57andIEEE118node system were used for cascading failure simulation to verify theaccuracy of the method, failure mechanism of large-scale power grid and mitigationstrategies were analyzed according to the fault simulation results.