Power Grid Risk Assessment Index System Based On Improved Power Betweenness

With the gradual increase of power demand and the rapid development of power system,the safe operation of power grids is becoming more and more important in ensuring people's life and social production.Therefore,it is important to study grid risk.At present,the grid company takes more and more attention into social losses caused by power grid failure in actual operation,focusing on the power outages impact on different users of production and life.This paper will focus on the above factors,and propose a new evaluation method in the field of grid risk.The main contents of this paper include the following aspects:Firstly,in the light of the State Council Decree No.599 "Regulations on Emergency Treatment and Investigation of Electric Power Safety Accidents" and "Regulation on Investigation of Electric Power Accidents(Incidents)in China Southern Power Grid Co.,Ltd.",the impact of the grid on the user side after the accident has been stressed.In this paper,an improved power betweenness is proposed taking into account the social properties of generators and loads.Not only the improved power betweenness reflects the influence of power flow on the importance of nodes and lines in the grid,but also the relative economic factors of the generator and load nodes is introduced into the improved power betweenness.The key factors of the relative economic fact ors are social impacts,the nature of the generators and users.Improved power betweenness of node and improved power betweenness of line can measure the importance of nodes and lines taking into account factors which are generators and load social propert ies,and tidal current effects.Secondly,the improved power betweenness is introduced into the power grid risk evaluation index.In this paper,a new evaluation index system of grid fault severity is proposed.From the view of network topology,the improv ed power betweenness is introduced into the efficiency of grid considering the weight of primary power system and secondary power system.The improved power betweenness of the line is combined with the weighted flow entropy;and the node improved power betweenness is introduced into the voltage offset severity and the load loss severity.The importance of line and node is measured by improved power betweenness,and the improved power betweenness is introduced to the grid failure consequence index to overcome the shortcomings of the traditional risk assessment method which does not take the generators and load social properties and the influence of tidal current into consideration.Finally,based on the multiple risk indexes established in this paper,the intuitionistic fuzzy analytic hierarchy process(AHP)is proposed to analyze the severity index of the failure in grid.Intuitionistic Fuzzy Analytic Hierarchy Process not only considers the membership degree and non-membership information in decision-making process,but also reflects the information of hesitancy degree.When the decision maker hesitates in the evaluation process,it can objectively evaluate the consequence of grid failure.The Monte-Carlo method is used to analyze the risk of the power grid.The fault probability of the line in the power network takes into account the influence of the protection failure and the load of the line.The fault severity is the result of the intuitionistic fuzzy analytic hierarchy process and the grid risk can be obtained ultimately.In summary,this paper focuses on the social impact of grid failure and makes an in-depth study of the risk of power grid failure.The concept of the improved power betweenness and a new method of power network risk assessment are proposed and the validity is proved.