Application of wavelet transform to obtain the frequency response of a transformer from transient signals-Part 1: theoretical analysis Articles uri icon

publication date

  • July 2013

start page

  • 1709

end page

  • 1714


  • 3


  • 28

International Standard Serial Number (ISSN)

  • 0885-8977

Electronic International Standard Serial Number (EISSN)

  • 1937-4208


  • This paper introduces a new theoretical method to obtain the frequency-response curve with the transformer in service (online) from the transient signals analysis by applying the continuous wavelet transform. To validate the method, the transient signals were simulated in the Alternative Transient Program for two cases: 1) under injection of pulses over the 60-Hz wave and 2) under switching operations, respectively. To simulate the transformer, a suitable wide-bandwidth model was employed. This study proposes a new setup of the Morlet wavelet, denominated Morlet-Modified, which showed the best results obtained for our application purpose (FRA On-line). This paper is a contribution for signal processing for the online frequency-response analysis technique on transformers.


  • frequency response; power transformers; signal processing; transient analysis; wavelet transforms; alternative transient program; continuous wavelet transform; denominated morlet-modified wavelet tranform; frequency-response curve; online frequency-response analysis technique; signal processing; transformer simulation; transient signal analysis; wide-bandwidth model