Research On Vulnerability Identification Of Power Grid Based On Line Index Entropy

In recent years,with the expansion of power grid scale and its increasingly complex structure,if it is not properly handled,problems in some parts of the power grid will be affected by the energy chain transmission of relevant subsystems.In this case,how to locate the weak link of power system quickly and accurately after the disturbance of the power grid is the core of the power grid security analysis,which is of great significance to the stable operation of the system and the corresponding measures.In this paper,based on the concept of brittleness of the general system and its relevant entropy theory,it presents a way to identify the key vulnerable lines and gives their performance indicators.In this paper,the fragile line identification process is divided into two parts,namely the fragile line selection based on static security analysis Angle and dynamic fragile line selection method based on historical data.(1)In this paper,the process of identifying vulnerable lines is divided into two different levels,which are based on the selection of vulnerability lines based on static security analysis and the methods and processes of dynamic vulnerability line selection based on historical data.In the screening phase of vulnerable lines,the system entropy is based on the improved weighted tidal entropy index and the branch path disturbance entropy index considering the node voltage and phase Angle change respectively to identify the vulnerable branches,the multi-angle comprehensive plan and the vulnerable line influence factors to form the fragile line screening set.In the sorting phase of the fragile line,the comprehensive entropy index is adopted to stratify the fragile lines and to get more accurate ranking of vulnerable lines,so as to form a set of four vulnerable levels,such as fixed vulnerability device set,serious vulnerability device set,high vulnerability device set and medium vulnerability device set.(2)From the dynamic point of view,considering the characteristics of the characteristics in the operation of the power grid,the screening process of some lines in a single mode may be covered,so the data accumulation of the static identification results is proposed,and the data mining can be carried out when the number of samples is increased to a certain amount,so as to complete the identification process of the unknown line according to the established eigenvalue index system and give the identification results quickly online.The eigenvalue index system used to determine line has been presented in this article as well as the methods of data accumulation and the method for identification of vulnerable lines.(3)Finally rely on electricity academy PSD-BPA and MATLAB simulation platform for IEEE10 machine 39 node system example case analysis,and compared the results with existing research results,proved the proposed method in this paper can comprehensively and accurately identify vulnerable lines.In particular,the dynamic vulnerability line screening based on historical data has certain reference value for realizing online screening.