Thermal Ageing of Dry Cellulose Paper Impregnated with Different Insulating Liquids—Comparative Studies of Materials Properties
[ 1 ] Instytut Elektroenergetyki, Wydział Inżynierii Środowiska i Energetyki, Politechnika Poznańska | [ P ] pracownik
2024
artykuł naukowy
angielski
- power transformer
- cellulose insulation
- mineral oil
- synthetic ester
- natural ester
- ageing
- degree of polymerisation
- neutralisation value
- water content
EN Natural and synthetic esters are increasingly being chosen instead of mineral oil for environmental and fire safety reasons. However, their use in power transformers is limited due to insufficiently well-understood ageing processes affecting their properties and the properties of cellulosic materials impregnated with them. The research results presented in many scientific papers prove that the use of esters slows the ageing process of cellulosic materials. This article presents the results of research aimed at answering the question of whether the effect of slowing the ageing process will also occur in the case of insulation with very low initial moisture. The answer to this question will allow us to better understand the role of water in the ageing process of the transformer’s insulation system. The thermal ageing process was carried out at a temperature of 150 °C in closed systems. The degree of cellulose polymerisation was taken as a measure of the degree of paper ageing. Great attention was paid to measuring the water content in both paper and electro-insulating liquids at various stages of their ageing. Furthermore, measurements of the properties of electro-insulating liquids were made, which are considered markers of ageing. The test results obtained indicate that in the case of a dry insulation system, corresponding to the initial moisture of the new units, the type of liquid used to impregnate the cellulosic material does not significantly affect its depolymerisation process. However, in the case of paper impregnated with natural esters, a lower dynamic of moisture increase in insulation was observed.
784-1 - 784-17
Article number: 784
CC BY (uznanie autorstwa)
otwarte czasopismo
ostateczna wersja opublikowana
w momencie opublikowania
publiczny
140
3 [Lista 2023]