| With the continuous development of modern science and technology,a variety ofhigh-power electronic loads are widely used in various industries.This makes the utilitygrid harmonic pollution is worsing, and led to a declining power quality.As the countriesand people’s demand of the power quality has been increasing rapidly, which requires usto be accurate on the power system harmonic analysis.Harmonic Detection of all harmonics as the starting point in the analysis of a series ofharmonic problems is very important.From the several current existing harmonic detectionmethods, the Fourier transform analysis of harmonic detection theory has been widely used,but this method requires taking the entire cycle synchronous sampling, otherwise thesampling results will be significantly affected.A new function of Hanning Self-convolution window as well as its improved FFTmethod of the analysis of Harmoinc improvement is put forward according to theproblem(fence effect and the spectrum leakage phenomenon)of Harmonic detection ofpower system in this paper.It can be seen that the side lobe decay rate of two orderHanning self convolution window is higher than the sidelobe level of classical functionwhich owns the same length by compared convolution computation by two Hanningwindow functions and the amploitude frequency response characteristics of othercommonly used window functions,so it can more effectively inhubit the specralleakage.Windowed interpolation algorithm is introductioned in the paper and theamplitude of FFT algorithm of two order hanning self convolution window is adjusted byusing Shuangfeng spectrum line interpolation.In this paper,we use MATLAB simulation, combined with selected several commonlyused algorithms,to analysis a given harmonic harmonic signal, and get the correspondingspectrum analysis diagram and the corresponding value of the parameter. The results provethat self-convolution based on second Hanning window FFT algorithm improved thedetection accuracy. |
PDF Full Text Request