Effect of Cellulose Contaminant on Dielectric Strength of Circulated Synthetic Ester Oil

This study focuses on the investigation on the effects of circulation velocity and various cellulose contaminants to the dielectric strength of circulated synthetic ester oil under AC Voltage. A specialized chamber was devised to replicate the circulation conditions of oil within an operational transformer. The experimental findings indicate that higher concentrations of cellulose contaminant correlated with a reduction in AC breakdown voltage (AC-BDV). Conversely, an increase in circulation velocity leads to an enhancement in the AC-BDV of the samples, whether they are pure or contaminated with cellulose. To validate these findings, simulations utilizing the Finite Element Method (FEM) were conducted. The examination of the electric field distribution indicated that the presence of cellulose impurities intensified the electric field strength, whereas the circulation acted to mitigate this phenomenon.