A Synchrosqueezing Transform-Based Hybrid Method for Voltage Fluctuations Assessment

Voltage fluctuations caused by rapid reactive power consumption of loads and photovoltaic or wind generator output variations may produce flickers and cause undesired effects on electric power components and human eyes. This paper presents a hybrid approach for voltage fluctuations assessment by using a synchrosqueezing transform-based algorithm. The proposed method first gives characterization of voltage fluctuations through accurate extraction of the measured voltage envelope by the Hilbert transform. The synchrosqueezing transform and an unsupervised clustering method called mean shift are then applied to determine the number of frequency components and corresponding frequencies. It is followed by the implementation of the bandpass filters to detect the magnitude of each frequency component. The proposed hybrid method is tested by both simulations and field measurements. Results compared with other commonly seen methods show that the proposed method provides a more accurate assessment.