DC Conductivity of Electrical Pressboard Impregnated with Mineral Oil of Natural Origin at Various Moisture Levels

The paper details the findings from an investigation into polarization currents and direct current conductivity of electrical pressboard manufactured by Weidman. The pressboard exhibited moisture levels ranging from 1% to 6% by weight and was impregnated with NYNAS NYTRO BIO 300X, an insulation oil sourced from natural origins. The study involved analyzing how polarization currents and DC conductivity varied with time across measurement temperatures spanning from 20 °C to 70 °C. An Arrhenius plot was crafted, encompassing six temperatures across the entire measurement spectrum. Linear approximations were applied to the experimental data on the Arrhenius plot. From these plots, the activation energy of DC conductivity, determination coefficient (R
²
) values, and standard deviation were determined. The determination coefficient values nearing unity underscore the precision of the measurements and the consistency of temperature conditions. Notably, the study revealed an activation energy value of ΔW
σDC
 = 1.069 eV for the DC conductivity of pressboard impregnated with NYNAS NYTRO BIO 300X, a bio-oil of natural origin. (Abstract)