A Weighted Function Least Squares State Estimation Method Based on Residual Normalization

Abstract

The invention discloses a weight function least square state estimation method based on residual normalization, and belongs to the field of electric power system dispatching automation. The method comprises the steps that SCADA data, collected by a data terminal, of any time section, a network structure and parameter information are input firstly through a computer and a program and initialized; a node admittance matrix of a network is calculated, a zero-injection equality constraint equation is formed, and then a corresponding residual, a jacobian matrix and a weight function are calculated by comprehensively considering a voltage amplitude value measuring equation, an injection power measuring equation and a branch circuit power measuring equation and taking the node voltage amplitude value and phase angle as state variables; finally, the state variables are updated, convergence judgment is conducted, and the state estimation of a power grid is achieved. By means of the weight function least square state estimation method based on residual normalization, bad lever measurement can be effectively restrained, high robustness and good convergence are achieved, the computational efficiency is very high, and a good engineering application prospect is achieved.

Description

technical field [0001] The invention belongs to the field of power system scheduling automation, and in particular relates to a weight function least square state estimation method based on residual normalization. Background technique [0002] Power system state estimation is an important part of the energy management system and the basis for running other application software in the power system. The results directly affect the intelligent analysis and decision-making of power grid dispatching. Since Schweppe introduced the state estimation into the power system for the first time in 1970, scholars and engineers at home and abroad have conducted a large number of in-depth research and practice on state estimation, and various state estimation methods have emerged during this period. [0003] At present, Weighted least squares (WLS) is one of the most widely used methods in state estimation. Its model is simple and easy to solve, but it is not anti-interference, so robust st...

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Problems solved by technology

However, in the calculation of these methods, the calculation of the standardized residual will consume a lot of time for each iteration, which affects their application in the actual system.

[0004] Based on this, there have been proposed methods that can improve computational efficiency to a certain extent, but the solution process is complex, and the calculation amount for some large power systems is too large, so it is not easy to be widely used

Some people also proposed the state estimation algorithm (Exponential least absolute value, E-LAV) of the exponential weight function, which improves the calculation efficiency, but the ability to resist bad leverage measurement is low

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