Bubble Effect Phenomenon in Modern Transformer Insulation Systems Using Aramid-Based Materials and Alternative Insulating Liquids
[ 1 ] Instytut Elektroenergetyki, Wydział Inżynierii Środowiska i Energetyki, Politechnika Poznańska | [ D ] phd student | [ P ] employee
PL Zjawisko bąbelkowania w nowoczesnych układach izolacyjnych transformatorów wykorzystujących materiały na bazie aramidu i alternatywne ciecze izolacyjne
2023
scientific article
english
- bubble effect
- aramid insulation
- high temperature insulation
- power transformers
- synthetic ester
EN One of the possible causes of transformer failures is high moisture in the winding insulation system. In an extreme case, when the critical temperature is exceeded, a sudden release of water vapor from the transformer insulation, called the bubble effect, can occur. This article analyzes the initiation temperature of the bubble phenomenon in various solid insulation materials (Kraft cellulose paper and aramid-based high-temperature papers such as Nomex® 910 and Nomex® 926) immersed in two electro-insulating liquids (mineral oil and Midel 7131 synthetic ester). The initiation temperature of the bubble effect depends mainly on the moisture content of the solid insulation, but it was found to be slightly lower for high-temperature materials than for cellulose. However, after taking into account the differences related to uneven water absorption of the tested materials, the differences in the initiation temperature of individual solid materials are very small. Synthetic ester, compared to mineral oil, slightly increases the bubble initiation temperature, regardless of the solid material used.
1 - 15
CC BY (attribution alone)
open journal
final published version
at the time of publication
public
140
3,2 [List 2022]