Parameter Estimation of Voltage Flicker Based on Hilbert Transform and Pisarenko Harmonic Decomposition

Accurate estimation of frequency and magnitude parameters of each modulation component in voltage flicker is necessary for precise flicker severity evaluation. In this paper, a new parameter estimation method for voltage flicker is proposed in which Pisarenko harmonic decomposition (PHD) analysis is used to estimate the flicker parameter included in flicker envelope detected by Hilbert transform. The total number of modulation components required in the PHD estimation process is obtained by FFT analysis. Simulations using the proposed method are made based on the single-frequency and multi-frequency modulated flicker respectively as well as using the FFT spectral analysis method under the setting SNR. Through comparison of the estimates resulting from the two parameter estimation methods, it can be concluded that the proposed method is capable of accurate estimation of frequency and magnitude of the modulation components in voltage flicker.