During the detection of voltage flicker parameters using HHT algorithm, the intrinsic mode functions (IMF) generated by empirical mode decomposition (EMD) are not ideal and the measuration errors are greater. This paper presents an modified HHT detection method of voltage flicker. Firstly, by adding the four point interpolation subdivision algorithm in the EMD “sifting” steps, a group of control points are split and the fitting curve is formed by cubic-spline interpolation, and then a set of IMF components are decomposed. Finally, the Hilbert transform is used to obtain the voltage flicker parameters. As to single component flicker signal containing noise and multi- component flicker signal containing noise or no noise, the simulation experiment was carried out by using HHT method and modified HHT method respectively. The research results show that the modified HHT algorithm has better anti-noise ability, which can suppress the modal aliasing and improve the accuracy of flicker signal parameters detection.
