Harmonic analysis based on time domain mutual-multiplication window

Abstract

The signal spectral leakage and fence effect are prone to take place during the power harmonic analysis by fast fourier transform (FFT) under asynchronous sampling. The inhibiting ability of classical window functions is restricted by side-lobe behaviors. A new type window function called time domain mutual-multiplication window, is obtained by multiplication operation of several window functions. A novel approach of harmonic analysis is developed through analyzing performances of main-lobe and side-lobe of the new window. Simulation results show that the time domain mutual-multiplication window can significantly suppress frequency spectral leakage and improve the accuracy of harmonic parameter estimation.

Enhanced Dual-Spectrum Line Interpolated FFT with Four-Term Minimal Sidelobe Cosine Window for Real-Time Harmonic Estimation in Synchrophasor Smart-Grid Technology

“…Here α takes integer values, and N is fixed to 2 k , where k is a natural number. Based upon the window function given in Equation (1) various advanced CWs are derived for harmonic estimation [7][8][9][10][11][12][13][14][15][16]18,19,[21][22][23]. Given the main lobe, sidelobe, and sidelobe roll of rate requirements a 4MSCW is adopted for harmonic and synchrophasor estimation, a PLIS-based DSLIFFT algorithm has been developed to improve its accuracy matching with the RT signal analysis.…”

“…This procedure effectively decreases the computation process. However, the peak search process in the conventional DSLIFFT algorithm reported in the literature [11][12][13][14][15][16][17][18][20][21][22][23] will check for the entire frequency bin peak locations, which in turn increases the computation burden.…”

“…After obtaining the locations of the spectral lines, an interpolation method is applied to estimate the amplitude, phase, and frequency of the harmonic signal. The conventional DSLIFFT algorithm presented in the literature [11][12][13][14][15][16][17][18][19][20][21][22] is improved by using the PLIS method. The spectral line location of the h th harmonic component can be obtained from the PLIS method.…”

“…The pictorial representation of the PLIS-based DSLIFFT using 4MSCW is illustrated in Figure 2. The frequency spectrum expression is written as [11][12][13][14][15][16][17][18][19][20][21][22]:…”

Spectral correction method based on improved flat-top convoluted window for parameter estimation of power harmonic

“…Recently, various methods have been presented for the harmonic parameter estimation [3][4][5]. Among these methods, the fast Fourier transform (FFT) method is the most commonly used technique because of its simplicity and availability in real-time applications [6].…”