Fundamental wave and harmonic wave parameter estimation method based on incomplete improved S transformation

Abstract

The invention discloses a fundamental wave and harmonic wave parameter estimation method based on incomplete improved S transformation. According to the method, a data collecting and preprocessing module (1), an incomplete improved S transformation computing module (2) and a fundamental wave and harmonic wave parameter estimation module (3) are included. The data collecting and preprocessing module (1) conducts standardized processing on collected data; the incomplete improved S transformation computing module (2) conducts incomplete improved S transformation computing on standardized data; the fundamental wave and harmonic wave parameter estimation module (3) obtains fundamental wave and harmonic wave amplitudes through a row amplitude vector center section mean of the incomplete improved S transformation at first, and then obtains the frequency and phase correction values of fundamental waves and harmonic waves according to the amplitudes by adopting inverse function values of a sinc function and polarities of spectrum peak frequency coordinate difference values and secondary maximum spectrum lines of fundamental waves and harmonic waves corresponding to spectra, and then the frequencies and phases of the fundamental waves and the harmonic waves are obtained. The method provides a real-time and precise means for detecting fundamental wave and harmonic wave parameters of an electric system.

Description

technical field [0001] The invention relates to the field of power system power quality signal analysis and parameter estimation, in particular to a fundamental wave and harmonic parameter estimation method. Background technique [0002] Power system harmonics are a very harmful power quality problem. In order to control harmonics in a targeted manner, it is necessary to quickly and accurately estimate its parameters. [0003] Existing harmonic parameter estimation methods often use FFT (Fast Fourier Transform) for analysis, but FFT has fence effect and spectrum leakage, and accurate parameter values ​​can only be obtained on the basis of strict synchronous sampling. In order to overcome the lack of parameter estimation of the FFT method in the case of non-synchronous sampling, some correction methods for spectrum analysis are produced on the basis of the FFT method. The principles are based on the windowing type of FFT analysis and the related properties of FFT to determine...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a method for estimating fundamental and harmonic parameters based on improved incomplete S transform, by performing subsequent calculation of S transform only for fundamental and harmonic spectrum peak frequency coordinates, and using incomplete S transform to estimate the frequency spectrum Correction feature of leakage to address accuracy and real-time issues of fundamental and harmonic parameter estimation

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