Multi-principal component modal analysis method for electric power network node harmonic characteristic analysis

Abstract

The present invention provides a multi-principal component modal analysis method for electric power network node harmonic characteristic analysis. The method comprises the following steps of: 1, constructing a node admittance matrix of an electric power network, and performing characteristic decomposition of the node admittance matrix; 2, constructing a node admittance equation of the electric power network, and obtaining modal impedance of the nodes of the electric power network; 3, performing ordering of characteristic roots of a modal impedance matrix, and determining the number of reservedcharacteristic roots according to an index of a cumulative variance contribution rate; 4, calculating an index of a harmonic distortion level of the power grid; and 5, calculating harmonic risk evaluation indexes of the nodes of the electric power network. On the basis of a traditional modal analysis method, the index of the cumulative variance contribution rate is employed to determine the number of the reserved characteristic roots to avoid the problem that rich harmonic components injected into the electric power network comprise harmonic waves with unresonance frequencies and a conditionthat single modal quantity takes the lead is destroyed to cause that the analysis precision of the harmonic characteristics of the nodes of the electric power network cannot reach the requirement.

Description

technical field [0001] The invention relates to the field of harmonic analysis of power networks, in particular to a multi-principal component mode analysis method for analyzing harmonic characteristics of power network nodes. Background technique [0002] With the promotion of power electronic equipment in the power network, the increase of nonlinear loads, especially the application of high-voltage direct current transmission technology, the harmonic problem of the power network has become more and more serious. Therefore, it is necessary to evaluate the harmonic characteristics of the system. [0003] Existing harmonic analysis methods can be divided into time domain analysis methods and frequency domain analysis methods. [0004] The time-domain analysis method mainly refers to electromagnetic transient simulation. This method performs real-time analysis on power network scenarios. Although the accuracy is relatively good, this method requires high component parameters,...

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Problems solved by technology

[0008] The purpose of the present invention is to provide a multi-principal component modal analysis method for harmonic characteristic analysis of power network nodes, which can solve the problems existing in the traditional time domain analysis method and frequency domain analysis method described in the background technology, and can also Solve the problem that the traditional modal analysis method can only analyze the harmonics of the resonant frequency, but not the harmonics of the non-resonant frequency

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