A Novel Synchronous Sampling Algorithm for Power System Harmonic Analysis

Abstract

Spectral leakage is one of the perilous effects on the accuracy of harmonic analysis based on Discrete Fourier Transform (DFT)/Fast Fourier Transform (FFT). FFT will provide accurate harmonic estimation when the sampling is synchronous. If the sampling is asynchronous it leads to spectral leakage and picket fence effect. Depending upon the system fundamental frequency spectral leakage and picket fence effect will cause a huge error in harmonic estimation while using FFT algorithm with constant sampling rate. Different types of windows with good sidelobe and narrow main lobe width are used to condense spectral leakage and interpolation techniques are used to condense picket fence effect. Various algorithms are available in the literature to minimize the effects of spectral leakage and picket fence effect but they require huge computation time to solve higher order equations. In this paper a novel algorithm is introduced to transform asynchronous sampling to synchronous sampling with customized mathematical formula. It mainly focuses on reducing the spectral leakage effect with less computation involved. The major advantage of the proposed method is that it can easily calculate harmonic parameters without solving any higher order polynomial equation. Simulation results illustrate that this method can enhance the accuracy of harmonic analysis by reducing spectral leakage efficiently.