Analyse de la reponse dielectrique du complexe papier-huile dans les transformateurs de puissance.

摘要

Life span of high power transformers is dependent on the life span of their solid insulation, internal windings paper. Non-destructive testing methods of the insulation have been developed in recent years including the dielectric measurement method. Studies have shown that dielectric measurements are function of humidity, temperature and the degree of aging of the transformers paper/oil insulation.;Keywords: cellulose, paper, aging, temperature, geometry, humidity, transformer, dielectric response, oil.;The objective of this study is to separate the contribution of the aging of the paper from the contributions of others factors such as humidity and oil aging. The oil/paper insulation measurements demonstrated that humidity can be isolated from aging in the presence of low percentage of humidity in the paper. The measurements of winding samples showed that there is no correlation between dielectric measurements and the degree of polymerisation, which is depending on the degree of aging of the paper. The measurement variations were due to the oil aging.