Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

This contribution is not only intended to provide a fresh review for researches on static electrification, but also contains a sub- stantial amount of new material with a view of closing some gaps in the present state of knowledge of oil streaming electrification. In this paper, the Electrostatic Charging Tendency (ECT) of fresh (unaged) and aged transformer oils were investigated in a spinning disk system. Static electrification measurement at different aging degrees was carried out under laboratory controlled conditions. Changes in static elec- trification were compared to some classical aging indexes (conductivity, dissipation factor, water content, resistivity, etc.). Fast, inexpensive and reliable laboratory testing procedures developed by American Society for Testing Materials (D 6802 and D 6181) were also used to monitor decay products as trace impurities. The obtained results show that static electrification currents increase with temperature, fluid mo- tion velocity, surface properties and the aging byproducts of the oil. The polarity, the amplitude and the time constant of the electrification currents are also affected. The results show that static electrification has relationship with thermal aging and is sensitive to turbidimetric and spectrophotometric measurements.