A method and device for analyzing harmonics and interharmonics in power systems

A power system and analysis method technology, applied in spectrum analysis/Fourier analysis, electrical digital data processing, complex mathematical operations, etc. performance, high precision

Active Publication Date: 2021-10-01
HENAN INST OF ENG
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  • Claims
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Problems solved by technology

[0005] The purpose of the present invention is to provide a method and device for analyzing harmonics and inter-harmonics in a power system, which is used to solve the problems of low accuracy and large amount of calculation in the estimation of harmonics and inter-harmonics parameters in the prior art

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  • A method and device for analyzing harmonics and interharmonics in power systems
  • A method and device for analyzing harmonics and interharmonics in power systems
  • A method and device for analyzing harmonics and interharmonics in power systems

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Embodiment Construction

[0025] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0026] Method example:

[0027] This embodiment proposes a method for analyzing harmonics and interharmonics in a power system, such as image 3 shown, including the following steps:

[0028] 1. First use the Root-MUSIC algorithm (root-finding multiple signal classification algorithm) to estimate the (inter) harmonic frequency of the signal. According to the frequency interval between (inter) harmonic frequencies and the set interval threshold, the (inter) ) harmonics are grouped.

[0029] Specifically, the harmonic and interharmonic sampling signals (power signals) of the power system are expressed as:

[0030]

[0031] Among them, x(n) is the sampling signal; n is the number of sampling points; T s is the sampling period; p is the number of harmonics and inter-harmonics; f i is the frequency of the i-th harmonic or inter-harmonic c...

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Abstract

The invention relates to a method and device for analyzing harmonics and inter-harmonics in a power system, belonging to the field of power grid harmonic analysis. The method includes obtaining power system signals, and using the Root-MUSIC algorithm to obtain the harmonic and inter-harmonic frequencies of the signals , group harmonics and inter-harmonics according to the frequency interval between two adjacent frequencies in the harmonics and inter-harmonics and the set interval threshold; for the windowed signal, use the discrete Fourier transform Perform spectrum analysis to obtain the spectrum of the signal after windowing processing; when the number of harmonics and inter-harmonics in the grouping is M≥2, select the M spectral lines closest to each harmonic and inter-harmonics in the grouping, and construct the spectrum The system of line equations solves for the magnitude and phase of harmonics and interharmonics. After the frequency of harmonics and inter-harmonics is estimated by the present invention, the (inter-) harmonics are grouped and solved according to the frequency interval, and the calculation amount is small, which can effectively overcome the inter-harmonics with similar frequencies and the gap between harmonics and inter-harmonics. Interference between the main lobe, so as to obtain higher precision amplitude and phase.

Description

technical field [0001] The invention belongs to the field of electric network harmonic analysis, and in particular relates to an analysis method and device for harmonics and inter-harmonics in a power system. Background technique [0002] In recent years, with the widespread application of new energy generation and power electronics technology in power systems, a large number of harmonics and interharmonics have appeared in the power grid. At the same time, various sophisticated electrical equipment sensitive to power quality are also The continuous popularization has made the problem of harmonics and inter-harmonics more prominent. Accurate analysis of power grid (inter) harmonics is the premise of power quality monitoring, harmonic control, and power metering. Several common methods of harmonic analysis are introduced: [0003] FFT (Fast Fourier Transform, Fast Fourier Transform) is a common method for (inter) harmonic analysis at present, but there will be problems of sp...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01R23/16G06F17/14
CPCG01R23/16G06F17/141
Inventor 蔡晓峰张鸿博窦小磊王佳欣
Owner HENAN INST OF ENG
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