An Algorithm with High Accuracy for Harmonic Analysis of Power System

Comparing the existing window interpolation correction algorithm with Kaiser window, the former´s performance is restricted by the window function fixed side-lobe, it can also reduce the influence of spectral leakage and fence effect. The latter can reach the nearly maximum energy proportion of the main-lobe to side-lobe, and the ratio between main-lobe and side-lobe width can be chosen freely. This paper proposes an approach for power harmonic analysis based on Kaiser window triple-spectrum-line interpolation FFT. And the interpolation formulae of the fundamental and harmonic frequencies, amplitudes and initial phase have been deduced. Simulation results show that the proposed algorithm can be easily designed and realized with higher accuracy of harmonic parameter estimation even if white noise exists or fundamental frequency changes. Therefore, the algorithm can effectively eliminate the influence of spectral leakage and fence effect, improving the accuracy of harmonic analysis.