Influence of temperature and moisture content on frequency response analysis of transformer winding

Mehdi Bagheri, B. T. Phung, Trevor Blackburn

Research output: Contribution to journalArticlepeer-review

51 Citations (Scopus)


Frequency Response Analysis (FRA) has been in use since the last decade as a sensitive method for detecting transformer internal defects. This study is focused on the influence of temperature and moisture migration on the FRA response of transformer winding. It also discusses the feasibility of FRA capability in moisture diffusion recognition in transformer paper insulation. To conduct this study, a single phase model transformer involving concentric LV and HV windings and a 20/0.4 kV, 1.6 MVA threephase two windings transformer are taken as test objects. Experiments are carried out at different temperature and moisture conditions. FRA spectra are then recorded and analyzed. FRA spectra deviations as well as total capacitance variations due to the temperature and moisture changes in the test objects are calculated. Karl-Fischer Titration (KFT) is utilized to monitor the moisture migration within oil and paper insulations. Furthermore, a mathematical model is used to simulate one of the test object windings and verify the experimental result, and also clarify the main reason of FRA spectrum deviation in this circumstance. Finally, statistical indices in FRA evaluation are calculated to explore their capability in FRA spectrum interpretation once the moisture content of paper insulation is changed.

Original languageEnglish
Article number6832288
Pages (from-to)1393-1404
Number of pages12
JournalIEEE Transactions on Dielectrics and Electrical Insulation
Issue number3
Publication statusPublished - Jun 2014
Externally publishedYes


  • Frequency response analysis
  • Karl-Fischer titration
  • moisture content
  • transformer diagnosis
  • transformer winding temperature

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Influence of temperature and moisture content on frequency response analysis of transformer winding'. Together they form a unique fingerprint.

Cite this