Cellulose Ester Insulation of Power Transformers: Researching the Influence of Moisture on the Phase Shift Angle and Admittance

Autor: Pawel Zukowski, Przemyslaw Rogalski, Tomasz N. Koltunowicz, Konrad Kierczynski, Jan Subocz, Marek Zenker
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Energies, Vol 13, Iss 20, p 5511 (2020)
Druh dokumentu: article
ISSN: 1996-1073
DOI: 10.3390/en13205511
Popis: This study investigates the frequency–temperature relations between the phase angle φ and admittance Y for composites of cellulose, synthetic ester, and water nanoparticles. We determined the activation energy value for the relaxation time of a phase shift angle ΔWφ ≈ (0.783 ± 0.0744) eV, which was related to the shift of φ(f) waveforms in higher frequency area with increasing temperature. We found that the position of admittance frequency waveforms in double logarithmic coordinates was simultaneously influenced by the temperature dependence of admittance and its relaxation time. Activation energy values for the relaxation time of admittance ΔWτ ≈ (0.796 ± 0.0139) eV and the activation energy value of admittance ∆WY ≈ (0.800 ± 0.0162) eV were determined. It was found that all three activation energy values were identical and their average was ΔW ≈ (0.793 ± 0.0453) eV. Impregnation with synthetic ester resulted in a decrease of activation energy by 0.26 eV compared to the impregnation with insulating oil. This was related to higher dielectric permittivity of the synthetic ester.
Databáze: Directory of Open Access Journals
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