Detection of voltage envelope using prony analysis-Hilbert transform method

This letter presents an efficient method for the detection of the instantaneous flicker level. The technique is based on extracting the magnitudes, frequencies, and phase angles of all frequency components of the voltage envelope using Prony analysis. By reconstructing the voltage waveform as linear combination of sinusoids, Hilbert transform can be applied to the predicted signal to develop the envelope of the voltage waveform. Two cases of flicker with single low frequency and wide band frequency inter-harmonics are investigated using simulated voltage signals. Simulations results are discussed.