Harmonic analysis method based on windowed interpolation FFT (Fast Fourier Transform) base frequency tracking technology

A technology of harmonic analysis and windowed interpolation is applied in the field of harmonic analysis based on the windowed interpolation FFT fundamental frequency tracking technology, which can solve the problems of leakage error, existence of fence effect, and inability to directly obtain accurate values ​​of sub-harmonic components, etc. Achieve the effect of high precision and reduced computational complexity
CN102128982AInactive Publication Date: 2011-07-20创锐装备智造(西安)股份有限公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
创锐装备智造(西安)股份有限公司
Publication Date
2011-07-20
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a harmonic analysis technology of electric energy, in particular to a harmonic analysis method based on a windowed interpolation FFT (Fast Fourier Transform) base frequency tracking technology, belonging to the technical field of power electric energy quality analysis. The analysis method comprises the following steps of: a. acquirement of higher-precision base frequency: sampling by a low-frequency sampling rate electric energy signal; after adding a Hanning window to sampled data, carrying out FFT calculation; obtaining a higher-precision base frequency f by an interpolation method; and b. base frequency tracking and synchronous frequency doubling: sampling the electric energy signal again at the frequency of 128*f and carrying out FFT calculation on the sampled data to obtain amplitudes and phases of all harmonic waves. By adopting the technical scheme, compared with the prior art, the invention has the advantages of reducing the calculation complexity because a base frequency parameter is just calculated during windowed interpolation calculation and having higher precision of harmonic analysis results by realizing plesiochronous adoption by the base frequency tracking.
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Description

Technical field:

[0001] The invention belongs to the technical field of electric power quality analysis, relates to a harmonic analysis technology of electric energy, in particular to a harmonic analysis method based on a windowed interpolation FFT fundamental frequency tracking technology. Background technique:

[0002] In the harmonic analysis of electric energy signals, due to the existence of asynchronous sampling, the influence of leakage on the harmonic frequency resolution point is no longer 0, and there is a leakage error; in addition, because the harmonic components of the actual signal do not fall exactly at the frequency resolution point, but falls between two frequency resolution points. In this way, the exact value of each harmonic component cannot be directly obtained through DFT, and there is a fence effect.

[0003] In order to obtain accurate harmonic analysis results, the existing general method is: use the value of the adjacent frequency resolution point ...

Claims

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