A method for establishing a power line vulnerability identification model considering the connection of wind farms

Abstract

The invention relates to a power line vulnerability identification model building method taking wind farm access into consideration, comprising the following steps: disconnecting a line li; getting the power flow increment entropy index H(i) of the disconnected line li according to the power flow increment Delta Lambda ki borne by other lines lk and the power flow increment allowance Omega k which can be borne by the lines lk at the current time; and disconnecting all the lines in sequence to get a vulnerability identification model. The running state and the vulnerability evaluation index of network topology are both considered. In view of the problem that the traditional power flow transfer entropy cannot capture wind power fluctuation and does not take into consideration the ability of lines to bear power flow increment, the invention puts forward an improved method in which power flow increment allowance is added. Compared with the previous models, the improved power flow increment entropy can sensitively identify lines which do not bear a large amount of power flow transfer but have small transfer allowance.

Description

technical field [0001] The invention relates to the technical field of power system security defense, and more specifically, relates to a method for establishing a power line vulnerability identification model considering the access of wind farms. Background technique [0002] In recent years, cascading tripping and off-grid accidents of large-scale wind power systems at home and abroad have occurred frequently, which has aroused people's attention to the transmission mechanism of grid cascading faults and the vulnerability of power systems. As an extension of the concept of power system security, power system vulnerability reflects the ability of power system to withstand disturbance or failure. In the initial stage of cascading faults, a small number of components fail one after another. In the stage of accident expansion, it is closely related to the weak links in the power system. It is particularly important to quickly identify the weak links that restrict the safe oper...

AI Technical Summary

Problems solved by technology

The traditional power flow transfer entropy can identify those vulnerable lines that undertake large power flow transfer, but it does not take into account the ability of the line to withstand the power flow transfer, and because of the fluctuation of wind power, the line's ability to withstand the power flow transfer is constantly happening. Therefore, the traditional power flow entropy cannot better reflect the fragile characteristics of power lines that take into account the access of wind farms

[0007] 3) The change of the grid structure caused by the connection of wind farms cannot be well expressed through the node degree distribution, because the wind farm is connected to the power grid through the collector line, and for the grid-connected point, the degree distribution The change of the network is not big for the overall network, but this collector line is the only channel for the wind farm to send power, and it undertakes a relatively heavy power flow transmission task and a status of network connectivity.

Because the degree distribution focuses on the local information of nodes, but ignores the network connection mode, it is not accurate in the vulnerability identification of power lines considering the access of wind farms

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