The Analysis And Evaluation Of The Grid Line Vulnerability By AHP And Entropy Weight Method

In recent years, large-scale power outages occurred in the world several times. As traditional safe power system reliability analysis methods have been unable to effectively ensure the safe operation of the grid. In order to prevent large-scale blackouts, researchers began to make the concept of weak power lines. It tries to analyze some weaknesses grid before the accident, and repair or improve a weak line. Therefore, this paper attempts to study how to find the weak lines and analyze the reasons for the weak grid lines, to reduce the risk of the grid, providing a reliable guarantee.This paper introduces a number of reasons from abroad and the occurrence of large-scale blackouts. Paper describes the research methodology of risk assessment and grid fault, and summarizing the advantages and disadvantages of each method. Paper summarizes the current situation of China’s power grid reliability at the same times.In order to filter out weak line grid, paper attempts to introduce the concept of entropy on the grid, and using it to in identify the weak power grid line. According to the entropy principle, defining the trend of entropy, we propose to search for weak line by the method of the trend of entropy. In the light of the actual operating characteristics of the power system, we establish the branch line flow consequences of weak entropy calculation of entropy index and trend-based branch of the impact of weak branch index calculation. It is both the line and the line itself off the consequences of the strong level of degree two aspects to consider weak lines. In IEEE39 bus system, we propose to search for weak line by the method of the trend of entropy. Its calculation is consistent with other literature data comparison. It verifies the validity of the use of the trend line identification entropy weak degrees.This paper build a risk evaluation system based on fundamental principles after wake lin e filtration, which take entire network load conditions, voltage level and static security level i nto consideration. The study explores two empowerment approaches which are AHP and entr opy weight method. AHP is a subjective empowerment approach and obtains relative importa nce through compare within indicators. Entropy weight method is more objective and can refl ect the size of entropy hence amend AHP, which relies mainly on decision-makers’subjective judgment. Therefore, I proposes the modified entropy weight AHP to compare and analyze filt rated wake lines to find out the reason why they are wake after determine the index weight.In IEEE39 bus system, we determine the index weight using entropy method and AHP. According to the trend of weak entropy method screening lines, we compare weak lines with each other by fuzzy analytic hierarchy process, and analysis of weak lines impaction on indicators. It provides a pilot basis for solving and repairing weak lines.