Online tracking of voltage flicker utilizing energy operator and Hilbert transform

The Teager energy operator (TEO) and the Hilbert transform (HT) are introduced in this paper as effective approaches for tracking the voltage flicker levels in distribution systems. The mathematical simplicity of the proposed techniques, compared with the commonly used algorithms in the literature, renders them competitive candidates for the online tracking of voltage flicker levels. Moreover, the TEO and the HT are capable of tracking the amplitude variations of the voltage flicker and supply frequency in industrial systems with only a 3% margin of error. Such accurate tracking facilitates the implementation of the control of flicker mitigation devices. A detailed comparison of the two proposed approaches that profile the different factors affecting tracking accuracy is presented. The results are provided to verify the tracking capabilities of both HT and TEO and to indicate the superior performance of the TEO and the HT in tracking voltage flicker.