Improved modal analysis method of power distribution network harmonic resonance

Abstract

The invention discloses an improved modal analysis method of power distribution network harmonic resonance. The improved modal analysis method comprises the following steps that: a resonant frequency is determined through using a spectrum analysis method; the eigenvalue matrix of a node admittance matrix under the resonant frequency is obtained; the eigenvalues of the node admittance matrix are sequenced according to an ascending order, and the locations of the eigenvalues are recorded; and the first m minimum eigenvalues are selected as the feasible solutions of critical modes under the resonant frequency, critical right eigenvectors corresponding to each feasible solution are determined, the maximum right eigenvalues and the positions thereof of the critical right eigenvector feasible solutions can be obtained, and the positions are the feasible solutions of a highest excitation node. The improved modal analysis method of the invention has the advantages of high computational efficiency and accurate positioning of the highest excitation node, and the like, and is more suitable for the harmonic resonance analysis of a power distribution network.

Description

technical field [0001] The invention relates to the technical field of power system analysis and control, in particular to an improved modal analysis method for distribution network harmonic resonance. Background technique [0002] In recent years, with the continuous increase of electricity demand and the extensive application of frequency conversion technology, the nonlinear load in the distribution network has increased year by year, and the harmonic problem of the power grid has become increasingly serious, causing potential harm to the stable operation of the power grid. On the one hand, the existence of harmonics reduces the power quality of the power grid, endangers the safe and reliable operation of electrical equipment, increases the power loss of equipment, and even damages equipment, causing power outages. On the other hand, when the harmonic frequency in the power grid is close to the system resonance frequency, system resonance may be induced, resulting in reson...

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Problems solved by technology

[0004] Harmonic resonance analysis methods mainly include spectrum analysis, modal analysis, etc. Spectrum analysis can determine the resonance frequency, but cannot provide more information about resonance, such as the resonance position and the degree of influence of each component on resonance. Traditional modal analysis The method has attracted wide attention due to its high efficiency and convenience. By analyzing the characteristic roots of the node admittance matrix, various information of resonance can be obtained, such as the resonance frequency, the highest excitation point, the highest observation point, and the participation factor, but its calculation efficiency is low. And it is impossible to accurately judge the highest excitation node in the harmonic resonance of the distribution network

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