Research On The Recognition Of Key Nodes And Lines In Power Grid Considering Power Grid Structure And State

With the increasing scale of modern power systems,the failure of key nodes or lines in the power network often has a more critical impact in a major power outage.The failure of these links may lead to a large amount of load loss or abnormal changes in voltage,and the scale of China's power system is still expanding and complicating,with the socio-economic development gradually caused by these changes in the grid grid frame,so that the power network within the hidden many instability factors.Accurate measurement of key nodes and key lines in the power system has great economic value and social significance for the relevant power practitioners to prevent and eliminate potential accidents in the grid network at an early stage.In the key node identification model:this paper simulates the load change of the node,calculates the voltage change of all nodes of the grid and the tide change of all lines after the change,and analyzes the uniformity and aggregation of the distribution of voltage and tide change in the grid under the load change of the node based on the theory of Theil Entropy,so as to establish the Theil Entropy of voltage change and Theil Entropy of tide change;the keyness index of the grid structure is based on the mesoscale theory of complex network theory,proposes the maximum flow transmission contribution mesoscale,and quantitatively analyzes the utilization of tide on nodes.Based on the proximity centrality theory in complex network theory,analyze the effect of nodes on the proximity of the network and propose proximity centrality metrics.In the key line identification model:In this paper,we consider the voltage and tidal shock on the power grid after the line fault is disconnected,and propose the voltage change amount Theil Entropy and tidal change amount Theil Entropy based on the theory of Theil entropy,as well as the criticality of the node,and establish the critical line grid state identification index from the size of the voltage and tidal change amount and the equilibrium of the distribution in the whole network;in the grid structure angle of the line criticality evaluation,we analyze the utilization of each line in tidal transmission and the influence of the line on the network coupling,and propose the maximum flow transmission contribution of each line in terms of the mesoscale theory and proximity theory.In order to combine the indicators scientifically and effectively,this paper introduces an entropy-weighted hierarchical analysis weight allocation algorithm optimized by least squares to calculate the integrated weights to obtain the integrated criticality indicators,and uses the New England 10 machine 39 node system as an example to rank the key nodes and lines of the grid.In order to compare the advantages of the method in the paper in key node and line identification,it is necessary to verify the ranking results of the above-mentioned model simulations,and the subject study introduces network performance indicators to evaluate the results.