Research on the Influence of Moisture in the Solid Insulation Impregnated with an Innovative Bio-Oil on AC Conductivity Used in the Power Transformers
Artykuł w czasopiśmie
MNiSW
140
Lista 2024
| Status: | |
| Autorzy: | Żukowski Paweł, Kierczyński Konrad, Rogalski Przemysław, Okal Paweł, Zenker Marek, Pająk Rafał, Szrot Marek, Molenda Paweł, Kołtunowicz Tomasz |
| Dyscypliny: | |
| Aby zobaczyć szczegóły należy się zalogować. | |
| Rok wydania: | 2024 |
| Wersja dokumentu: | Drukowana | Elektroniczna |
| Język: | angielski |
| Numer czasopisma: | 20 |
| Wolumen/Tom: | 17 |
| Numer artykułu: | 5164 |
| Strony: | 1 - 15 |
| Impact Factor: | 3,0 |
| Web of Science® Times Cited: | 0 |
| Scopus® Cytowania: | 0 |
| Bazy: | Web of Science | Scopus |
| Efekt badań statutowych | NIE |
| Finansowanie: | The research was supported from the state budget within the program of the Ministry of Education and Science entitled ‘Science for Society II’ project no. NdS-II/SP/0173/2024/01 total project value PLN 1,462,590.80. |
| Materiał konferencyjny: | NIE |
| Publikacja OA: | TAK |
| Licencja: | |
| Sposób udostępnienia: | Witryna wydawcy |
| Wersja tekstu: | Ostateczna wersja opublikowana |
| Czas opublikowania: | W momencie opublikowania |
| Data opublikowania w OA: | 17 października 2024 |
| Abstrakty: | angielski |
| The study determines the frequency–temperature dependence of the conductivity of a moist solid insulation component of power transformers, impregnated with the innovative bio-oil NYTRO® BIO 300X, manufactured from plant-based raw materials. The research was conducted for six moisture levels ranging from 0.6% to 5% by weight, within a frequency range from 10−4 Hz to 5 · 103 Hz and measurement temperatures from 20 ◦C to 70 ◦C, with a 10 ◦C step. The conduction model for both DC and AC, based on the quantum mechanical phenomenon of electron tunneling between water nanodroplets, was used to analyze the obtained results. It was determined that the frequency dependence of the conductivity of pressboard-bio-oil-moisture composites is influenced by two factors as follows: the activation energy of conductivity and the activation energy of relaxation time. For each moisture content, 16 values of the activation energy of the relaxation time and 16 values of the activation energy of conductivity were determined. It was found that the values of activation energy of conductivity and relaxation time are equal and independent of moisture content, frequency, and temperature. Based on 192 residual activation energy values, the mean generalized activation energy value for the relaxation time and conductivity was calculated with high precision, resulting in ∆E ≈ (1.02627 ± 0.01606) eV. The uncertainty of its determination was only ±1.6%. This indicates that electron tunneling from the first nanodroplet to the second, causing AC conductivity, and their return from the second nanodroplet to the first, determining the relaxation time, occur between the same energy states belonging to the water nanodroplets located in the pressboard impregnated with bio-oil. For each moisture content, the curves obtained for different measurement temperatures were recalculated to a reference temperature of 20 ◦C using the generalized activation energy. It was found that the shifted curves obtained for different temperatures perfectly overlap. Increased moisture content shifts the recalculated curves toward higher conductivity values. It was established that for all moisture contents in the lowest frequency range, conductivity is constant (DC conductivity). A further increase in frequency causes a rapid rise in conductivity. The increasing period can be divided into two stages. The first stage occurs up to about 100 Hz–101 Hz, depending on the moisture content. In the second stage, the rate of conductivity increase is higher, and its value depends on moisture content. The lower the moisture content, the faster the conductivity increases. Recalculation using the generalized activation energy eliminated the effect of temperature on the curves. It was found that the shapes of the recalculated curves and their position relative to the coordinates depend only on the moisture content in the composite. The equality of the activation energy of the relaxation time and conductivity established in the study, as well as their independence from frequency and moisture content in the pressboard impregnated with NYTRO® BIO 300X bio-oil, allows for recalculatingthe curves of electrical parameters determined at any operating temperatures of the transformer to a reference temperature, for example, 20 ◦C. Comparing the curve obtained for the transformer, recalculated to the reference temperature, with reference curves determined by us in the laboratory for different moisture contents, will allow for the precise determination of the moisture content of the solid insulation component impregnated with NYTRO® BIO 300X bio-oil. This will contribute to the early detection of approaching critical moisture content, threatening catastrophic transformer failure. |
