Time-frequency analysis of power quality disturbances using synchroextracting transform

The joint time-frequency representation (TFR) provides the useful hidden information of a nonstationary signal consisting of several components. The time-frequency analysis methods with high resolution are of utmost importance in visual localization and recognition of nonstationary waveform in power quality (PQ) disturbance signals. This paper introduces a newly developed TFR technique known as synchroextracting transform (SET) for the detection and identification of various kinds of single and combined nonstationary PQ disturbances. The SET is a high-resolution TFR technique that belongs to a post-processing procedure of short-time Fourier transform (STFT) incorporating components of mode decomposition and signal reconstruction. The SET aims to retain the TF information related to time-varying features of the signal and removes most smeared TF energy. In the case studies considered here, several PQ disturbance signals are thoroughly analyzed by using SET.