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

Résumé

This study emphasizes the pre-breakdown phenomenon of low pour point synthetic esters with thermal degradation for potential usage in cold climatic regions. It is to be mentioned that two synthetic esters SE1 and SE2, having a pour point less than -50°C are chosen for this work. The investigations are aimed at understanding the pre-breakdown behaviour of these very low pour point liquids at room temperature. The testings are performed using a point-plane electrode configuration under AC stress in a hermetically sealed test cell. To understand the influence of thermal degradation, the insulating liquids are subjected to a controlled thermal stressing under sealed conditions. The measurements are reported at different thermal aging durations (2 weeks, 4 weeks, and 6 weeks) at a tip of radius 5.46 μm and 10.75 μm with an inter-electrode distance of 10 mm. The measurements include partial discharge inception voltage, breakdown-streamer-inception voltage, and acidity of the liquids at different aging conditions. The influence of thermal degradation on the partial discharge (PD) characteristics of the fluids is reported. In addition, a two-way ANOVA (with interaction) based statistical testing has been applied to test the plausibility of the hypothesis observed in the experimental findings.