Experiences from on-site dielectric spectroscopy measurements on power transformers

• Autorzy: Blennow J. , Ekanayake C. , Bartnicki A. , Gubański S.
• Konferencja: II International Conference on Advances in Processing, Testing and Application of Dielectric Materials, 15-17 September, Wrocław 2004
• Języki publikacji: EN

Abstrakty

EN

Dielectric spectroscopy field measurements were conducted both in frequency domain (FDS) and in time domain (PDC) on ten power transformers, most of them rated 130 kV/40 MVA. In addition, oil samples were taken for moisture content analyses and for conductivity measurements. The transformers selected for the measurements were of different types, originating from different manufacturers and having different age, up to 50 years old. Some of them have been known as being in bad condition. In general, the majority of the transformers were low loaded prior to the measurements. On two of the units the measurements were performed both before and after oil regeneration. Results of the oil analyses are compared with estimates obtained from the well-known XY-model and the simplified X-model. The results of the modelling show that both FDS and PDC provide information about the state of insulation. Oil temperatures as well as thermal equilibrium are critical factors for obtaining reliable results. The spectroscopy measurements provide better estimates of moisture content at low sample temperatures than the traditional Karl Fisher analyses.

Słowa kluczowe

EN

power transformer; field measurement; dielectric response measurements; frequency domain spectroscopy; time domain spectroscopy; insulation modelling; X-Y model; X model; oil conductivity; estimation of moisture content

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Prace Naukowe Instytutu Podstaw Elektrotechniki i Elektrotechnologii Politechniki Wrocławskiej. Konferencje
• Rocznik: 2004
• Tom: Vol. 40, nr 15
• Strony: 62--69
• Opis fizyczny: Bibliogr. 11 poz., rys., tab.

Twórcy

autor

Blennow J.

• Department of Electric Power Engineering, Chalmers University of Technology, SE ‒ 412 96 Göteborg, Sweden

autor

Ekanayake C.

• Department of Electric Power Engineering, Chalmers University of Technology, SE ‒ 412 96 Göteborg, Sweden

autor

Bartnicki A.

• Department of Electric Power Engineering, Chalmers University of Technology, SE ‒ 412 96 Göteborg, Sweden

autor

Gubański S.

• Department of Electric Power Engineering, Chalmers University of Technology, SE ‒ 412 96 Göteborg, Sweden

Bibliografia

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• [2] EKANAYAKE C., Application of Dielectric Spectroscopy for Estimating Moisture Content in Power Transformers, Thesis for the Degree of Licentiate of Engineering. Chalmers University of Technology, Gothenburg, 2003
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