Vulnerability Research For Cascading Failures Blackout In Power System Based On Complex Network Theory

With the development of the interconnected power system construction and power system’s capacity and scale expanding, the probability of complex chain of power outage is small, but it cannot avoid completely.Nowadays,the characteristics and element action among the chain failure is more and more complex and the sequence brought by the fault is also more serious,this may cause power grid collapse and large scope blackout accidents. In response to a cascading failure outage mechanism study of power grid dynamic behavior, the power grid power system security analysis method based on reductionism is insufficient, so the application of complexity theory, especially the complex network theory to analyze the complexity of grid and grid cascading failure mechanism and explain it is a natural choice, and currently received widespread attention.The generation of cascading failure in addition to outside interference and environmental factors, another important factor is its own existence of vulnerability of the grid. From this starting point, focusing on the network vulnerability analysis, carries on the research work.First of all,the research background and significance of this article has been summarized, the characterization of the basic characteristics of the statistical feature of complex network parameters and typical topology model has been introduced too.Mechanism of cascading failure has been explained by combining the theory of power system complexity and self-organized criticality theory, the typical blackouts in cascading failure model were introduced, on the basis of the established model of OPA based on DC current, using IEEE30node on the model, for example,to analyse the process of self-organization criticality of power system.Secondly, the weak link of grid components has been evaluated quantitatively based on the complex network theory t.With grid nodes as the research object, from the angle of the node’s control ability to the network resource, comprehensive consider the global vulnerability and local vulnerability of nodes, grid node vulnerability assessment model is established.With grid branch as the research object, consider an information network system coupled with the power of electric power to study its effect on the line open circuit information reliability of transmission, power grid vulnerable branch evaluation model is established.using IEEE39node model as an example to demonstrate the rationality and validity of the vulnerability assessment model of grid components’.Finally, on the basis of comparing existing betweenness index, considering the load level and generator power node and the load node’s width and depth of being used, on the basis of the deriving mathematical relationship between branch and node betweenness,an improved electrical betweenness index of the grid components is established, and also the physical significance and the relationship between the electrical betweenness.In multiple standard test system, for example, using the power-law distribution of the combination of the Gini coefficient method to analyze the existed heterogeneity characteristics of different topologies of power grid.In generally speaking,starting from the perspective of complex network’s topology structure, the inner mechanism of the power grid cascading failure has been studied from component level to the organizational structure level, using the concept of vulnerability and the weak links that exist in the power grid structure have been identificated too, which will be helpful to find the way to reduce the occurrence of cascading failure.