A new method for power flicker measurement based on interpolated DFT

Measuring power flicker is important in assessing the quality of the electric power. This paper introduces a new method on measuring the modulation ratio of voltage in flicker. We divide the samples of the fluctuating voltage into several groups according to its period. Then the interpolated discrete Fourier transform(DFT) based on Hanning window is used to analyze the rms of each period of samples. All of rms are sorted from small to large. The maximum and minimum rms are used to calculate the modulation ratio of the flicker. The simulation results show that the accuracy of the proposed method is high and it has a rapid computation speed.