New method for power flicker calibration based on interpolated DFT

Voltage fluctuation and flicker is an important aspect of power quality. The key of flicker analysis is to track the envelope of voltage signals and then calculate the short-term flicker severity. In this paper, a new method on calibration of flickermeters was presented. The method did not adopt the phase-locked loop between the flicker waveform generator and the DVM. It tracked the envelope by interpolated discrete Fourier transform to eliminate the measurement errors caused by the asynchronous sampling. The error of the new flickermeter calibration system was estimated to be about 10^-5.