Analysis of voltage flicker using Hilbert-Huang Transform

Hilbert Huang Transform (HHT), which was proposed by Huang and developed by Flandrin and his group, is a new signal processing method that can be used in the analysis of nonlinear and nonstationary signals. This study suggests an approach of using Hilbert Huang Transform to measure the voltage flicker in power systems. In the suggested method, voltage signal is decomposed into Emprical Mode Decomposition EMD and Intrinsic Mode Function IMF components. These components are used in the calculation of the frequency and amplitude of voltage flicker. The clear success of EMD in depicting envelope variations of a sinusoidal waveform has been the main motivation for the adoption of HHT in flicker analysis. Simulations are done by using input signal modulated with single flicker frequencies and multi flicker frequencies and input signals which include harmonic. Simulations show that the method may be used in voltage flicker analyse and gives good results.