Zero impedance branch self-adaptive computing method used for transmission network state estimation

Abstract

A zero impedance branch self-adaptive computing method used for transmission network state estimation relates to the technical field of transmission network steady-state analysis. The method solves the technical problem of low solving precision by using the current method. The method comprises the following steps: 1) searching the relationship between each subcircuit and each ring network and obtaining the relation set; 2) dividing the relation set in step 1 into zero branch set and non-zero branch set; 3) taking zero branch i, and obtaining each ring network set containing zero branch i; 4) acquiring a minimum branch impedance normalized value according to non-zero branch in each ring network set in step 3; 5) self-adaptively computing an impedance value of the zero branch according to the normalized value of the minimum branch impedance; 6) replacing the original impedance value of zero branch i with computing impedance value of zero branch i; 7) repeating step 3 to step 6 till all impedance values of zero branches are computed; 8) carrying out iterative computations on transmission network state estimation. The method provided in the invention can improve the estimation precision of the state estimation.

Description

technical field [0001] The invention relates to the technique of steady-state analysis of transmission network, in particular to a technique of zero-branch impedance self-adaptive calculation method for state estimation of transmission network. Background technique [0002] Transmission network state estimation (State Estimation, SE) is an important part of the energy management system (Energy Management System, EMS), its function is based on the available real-time measurement information, automatically eliminate the error information caused by random interference, Calculate the state variables of the power system (ie, the voltage amplitude and phase angle of all buses). [0003] The zero branch of transmission network state estimation refers to the branch with very small impedance (<<10E-6) in the node branch model of transmission network state estimation. On the zero branch, even if there is a large power flow, it will not cause a large voltage drop; but in the sol...

AI Technical Summary

Problems solved by technology

On the zero branch, even if there is a large power flow, it will not cause a large voltage drop; but in the solution equation of the state estimation of the transmission network, although the impedance of the zero branch is small, it may still cause the singularity of the state equation, Unreal solutions appear, thus affecting the accuracy of the equation solution

[0004] There are two methods to deal with the zero branch in the current transmission network state estimation solution equation: one is to merge the zero branch nodes, the defect of this method is that it cannot solve the branch power flow of the zero branch; the other is Set the zero branch impedance to a small impedance. Although this method can solve the branch power flow of the zero branch, there is no quantitative solution for the setting of the zero branch impedance value for different network structures. Seriously affect the estimation accuracy of transmission network state estimation

Images