Short-termflickerseverity indexcalculation using Hilbert-Huang Transform

Abstract

This article proposes an approach to calculate the short term flicker magnitude (Pst) using Hilbert-Huang Transform (HHT). HHT is an approach which is commonly used in the analysis of nonlinear and nonstationary signals. Since flicker corresponds to a variation of the envelope of a sinusoidal voltage waveform, the utilization of HHT is reasonable. The magnitude of the short term flicker (Pst) is an important power quality parameter that is established by the International Electrotechnical Commission (IEC). In the proposed method, the HHT parameters such as Empirical Mode Decomposition (EMD) and Intrinsic Mode Function (IMF) are evaluated. The short term flicker magnitude (Pst) is claimed to be determined as a nonlinear and statistical function of the waveform magnitude and frequencies obtained by EMD, which is known to succeed in determination of envelope variations. The proposed method is also experimentally observed to precisely determine the (Pst) value. © 2011 IEEE.