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

Abstract

Original scientific paper Accurate estimation of harmonic parameter is an important task in signal processing of power system. A new class of flat-top windows is proposed, which is generated by self-convolutions of the fast-decaying minimum-sidelobe flat-top (FDMS-FT) window in the time-domain. The mainlobe and sidelobe features of the new window are studied. In addition, to improve the flatness of mainlobe of the new window, the coefficients of its parent window are optimized. A window-length changeable discrete phase difference correction algorithm based on the new window is presented to estimate power harmonic parameter. In order to inspect the efficiency and accuracy of the presented method, several computer simulations and practical experiments were conducted with power multi-frequency signals. Results show that the proposed method can reduce the computation load efficiently and gives a high parameter estimation accuracy of power harmonic.Keywords: fast Fourier transform; flat-top window; parameter estimation; power system harmonic; spectral correction; spectral leakage Spektralna korekcijska metoda utemeljena na poboljšanom spiralnom podesivom prozoru za procjenu parametara harmonijske snage Izvorni znanstveni članak Točna procjena harmonijskog parametra je važan zadatak u obradi signala elektroenergetskog sustava. Predlaže se nova vrsta flat-top prozora koja se generira vlastitim konvolucijama brzo padajućeg flat-top prozora (FDMS-FT) u domenu vremena. Proučavaju se značajke bočnog i glavnog režnja novog prozora. Nadalje, kako bi se poboljšala glatkoća glavnog režnja novog prozora, optimiziraju se koeficijenti matičnog prozora. Predstavlja se izmjenjivi algoritam ispravke razlike faze duljine prozora baziran na novom prozoru kako bi se procijenio strujni harmonični parametar. Kako bi se provjerila učinkovitost i točnost prikazane metode, provedeno je nekoliko računalnih simulacija i praktičnih eksperimenata s višefrekvencijskim strujnim signalima. Rezultati pokazuju da predložena metoda može učinkovito smanjiti opseg računanja i daje visok parametar točnosti procjene harmonijske snage.

Non-linear dynamics modelling in accelerators with the use of symplectic integrators

“…The first change is related with the available windows (signal filtering). A new family of windows, the Flat-top windows [117][118][119][120], are included in the NAFF-UV code in addition to the rectangular (no window), the exponential and the Hanning of order p windows that are also included in NAFF code. Furthermore, their is the flexibility in the new code to use two different windows, one for the frequency (k n ) calculation and one for amplitude (z k n ).…”