Empirical mode decomposition application for short-term flicker severity

Authors: YASEMİN ÖNAL, ÖMER NEZİH GEREK, DOĞAN GÖKHAN ECE

Abstract: In this article, an approach based on empirical mode decomposition (EMD) is suggested in order to calculate short-term flicker severity, Pst, in power systems. EMD is a new signal processing method used for the analysis of nonlinear and nonstationary signals. Pst is an important quantity in the electric power quality index defined by the International Electrotechnical Commission. In the suggested approach, the voltage signal is separated into intrinsic mode function components using EMD. These components are used for calculating the voltage flicker amplitude and frequency, and Pst is calculated as a result of the statistical evaluation of flicker amplitude. EMD is thought to be efficient in finding the flickers and calculating Pst due to power to find the changes in the oscillating signal envelope of EMD. Simulations are made using an input signal modulated with single and multiflicker frequency. Simulations show that the approach is usable in the calculation of Pst and it gives good results.

Keywords: Short term flicker severity, empirical mode decomposition, intrinsic mode function, voltage flicker, power quality

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