Multi-Principal Element Modal Analysis Method for Harmonic Characteristics Analysis of Power Network Nodes

Abstract

The invention provides a multi-principal component modal analysis method for analyzing the harmonic characteristics of power network nodes, comprising the following steps: 1. Constructing the node admittance matrix of the power network, and performing eigendecomposition on the node admittance matrix; 2. Constructing the power grid The node admittance equation of the network is used to obtain the modal impedance of the power network node; 3. To sort the characteristic roots of the modal impedance matrix, determine the number of retained characteristic roots according to the index of the cumulative variance contribution rate; 4. Calculate the harmonic of the power grid 5. Calculate the harmonic risk assessment index of power network nodes. On the basis of the traditional modal analysis method, the present invention uses the index of cumulative variance contribution rate to determine the number of reserved modes, avoiding the harmonics of non-resonant frequency contained in the abundant harmonic components injected into the power network , the condition that the single modal quantity dominates is destroyed, which leads to the problem that the accuracy of the analysis of the harmonic characteristics of the power network nodes cannot meet the requirements.

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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