Research On Vulnerability In Power Grid Based On Complex Network Theory

Today,there are many large-scale blackouts occurred in the word.It has a serious effect on people's daily life and the national economic in many aspects.Traditional analysis methods based on reductionism have shown some limitations in explaining the mechanisms of large-scale blackouts and complex dynamics in power grid,while complex network theory broke the limitations in studying the structural vulnerability of power grid.There are some problems generally existed in studying structural vulnerability of power grid based on complex network theory.For example,model of power grid is simple and abstract.Failure index of power grid remains to be improved.Considered with the main problems,the structural vulnerability of power grid is researched in this paper.The improved model of electrical betweenness is defined in this paper.The electrical distance of “generator-load” nodes is added based on the existing models.It can conveniently and effectively reflect the distribution of electrical energy in power grid,and will make the result conform to the reality.Through the research of structural vulnerability and relevant factors,structural equilibrium and structural equilibrium degree are introduced in this paper.Gini index is introduced as a structural equilibrium degree.The standard test system of IEEE39 and central China 500 kV power grid are discussed in this paper as examples.PAJEK is used to build mathematical modeling and calculate the characteristic parameters of power grid.It uses MATLAB programming to identify the critical nodes and lines in power grid.After fault simulation of power grid,the fragile nodes and lines of the standard test system of IEEE39 and the central China 500 kV power grid are obtained.Using the improved electrical betweenness model,the result is testified that the fragile nodes and lines are more reasonable and effective.The relationship between structural equilibrium degree and structural vulnerability is utilized to evaluate the structural vulnerability of power grid.