Harmonic measurement method, electronic device and storage medium based on double spectral line transformation

Abstract

The present invention provides a harmonic measurement method based on dual spectral line transformation, electronic equipment and a storage medium. The method includes: S1. Sampling and obtaining the initial data set of the signal and performing complex processing with zeros to obtain the complex data set, and adding a window function to the complex data set Perform transformation to obtain the initial spectrum; S2. Calculate the spectral resolution of the initial spectrum and the number of spectral line intervals between integer harmonics, and determine the number of double spectral line transformations in the current measurement scene according to the increased range of spectral line transformation; S3. Pass Perform polynomial operations on multiple adjacent spectral lines in the initial spectrum to obtain the second spectrum after double spectral line transformation; S4. Obtain the average reference power frequency based on the second spectrum calculation, and then calculate the corresponding harmonic by the average reference power frequency Amplitude and phase, as well as correction, to obtain harmonic parameters; this method ensures good calculation accuracy under the premise of low computation, can be flexibly applied to harmonic measurement under different sampling conditions, and solves the problem of component submersion when spectrum leaks .

Description

technical field [0001] The invention relates to the technical field of harmonic measurement of electric power signals, in particular to a harmonic measurement method based on dual spectral line transformation, electronic equipment and a storage medium. Background technique [0002] With the continuous popularization of power electronic equipment, a large number of nonlinear loads are connected to the power system, which aggravates the harmonic pollution of the power grid and leads to serious power quality problems. Accurate measurement of harmonic parameters is an important basis for harmonic suppression and power quality control. [0003] In the field of harmonic measurement, spectral leakage will cause the mutual influence of spectral lines in the spectrum, and false spectral lines with different amplitudes will appear. This phenomenon is an important factor that reduces the calculation accuracy of harmonic parameters. In order to prevent the generation of spectrum leakag...

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Problems solved by technology

However, the complex spectral expression of the Kaiser window makes a large number of high-order operations in the parameter calculation process, so this method fails to solve the problem of large amount of calculation

Relevant scholars proposed a nine-point transformation improved FFT calculation method, which accelerated the attenuation of the side spectral lines on the basis of not adding a window function. However, this method cannot guarantee the linear phase of the spectrum, the stability is insufficient, and there is no basis for parameter selection. , cannot be flexibly applied to harmonic measurement under different sampling conditions

[0006] Therefore, the existing technology cannot solve the contradiction between high calculation accuracy and low calculation amount, and there is no basis for parameter selection, and it is difficult to deal with harmonic measurement under different sampling conditions

When the spectrum leakage is serious and the gap between adjacent harmonic content is too large, there will be a problem that the large component spectral line will submerge the small component spectral line, which will easily lead to incorrect spectral line search during the interpolation calculation process, resulting in serious calculation errors. The existing technology has not yet conducted detailed research on the problem of component submersion and provided relevant solutions

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