Resumen de Analysis of non‐stationary electric signals using the S‐transform

Zbigniew Leonowicz, Tadeusz Lobos, Krzysztof Wozniak

• Purpose – The purpose of this paper is to compare the accuracy of tracking the amplitude and frequency changes of non‐stationary electric signals.

  Design/methodology/approach – Short‐time fourier transform (STFT) and S‐transform algorithms were applied to analyze non‐stationary signals originating from switching of capacitor banks in a power system.

  Findings – The S‐transform showed possibilities of sharp localization of the basic component, and allowed improvement of tracking dynamism the transient components in comparison to STFT.

  Practical implications – S‐transform is a better tool for the analysis of non‐stationary waveforms in power systems and its properties can be used for diagnostic and power quality applications.

  Originality/value – The dynamic tracking of the changes in time and frequency of real‐like signals originating from a power system are investigated in this paper.