Research On Risk Assessment Of Power Grid Blackout Based On The Cloud Model Fuzzy Evaluation

With the rapid development of the economy and the gradual opening up of the power market,the scale of power grids is developing rapidly,while the overall security of power grids should not be underestimated.Although the frequency of power grid blackout is decreasing in recent years,it still happens from time to time and new threats such as network attack appear.The power grid blackout in foreign countries is of great significance for the further improvement of China’s power grid and risk prevention.At the same time,the power blackout causes great harm to social life and production.It is very important and necessary to identify the risk of power blackout and take timely warning and preventive measures.This paper mainly studies the risk assessment method of power grid blackout,hoping to provide reference for the safety management of power grid through the systematic study of power grid blackout.Firstly,this article summarizes more than 100 typical large-scale power outages at home and abroad.By analyzing the common features and characteristics of each power grid accident,the influencing factors and main risk causes of the power outage are identified,and the mechanism and coupling relationship between the accidents.Establish a large-scale power outage accident tree to obtain the action path of the large-scale power outage.Through the methods of minimum cut set,minimum diameter set and structural importance,the risk degree and action path of power grid blackout are analyzed.Secondly,the triangular fuzzy number method is used to calculate the probability of occurrence of the basic event of a large power outage based on the statistical probability of various events and expert experience.Based on the fuzzy accident tree of the large power outage,the risk of the top event of the large power outage is calculated from the bottom up.Thirdly,by analyzing the impact of a major power outage on social life,a comprehensive grid loss index system and a comprehensive loss assessment model including economic losses and social losses are established to quantify and analyze the magnitude of the losses caused by a maj or power outage.Finally,the method of fuzzy comprehensi ve evaluation based on cloud model is used to evaluate the probability of power failure and the risk level after the comprehensive loss set,and the comprehensive risk evaluation model of regional power grid is obtained.In addition,the application of a municipal power grid is studied and some suggestions are put forward according to the actual situation of the regional power grid.In this paper,when it comes to the risk degree of power failure,the factors of probability and loss are comprehensively considered.Meanwhile,the traditional method of simple multiplication is improved,and the fuzzy comprehensive evaluation method based on cloud model is adopted,which has important reference value and practical significance for improving the safety management level and risk control means of power grid.