Effect of Temperature on AC Breakdown Properties of Vegetable-Oil-Based Insulating Fluid

Abstract

This paper reports the temperature dependence of AC breakdown voltage (electric strength Fb) of vegetable-oil- based insulating fluid. We observed Fb of the soybean-oil-based insulating fluid, at the wide temperature regions (-50 to 100 [°C]). These results were shown as the following: (i) Fb showed the constant value between about -10 [°C] to room temperature. (ii) At low temperature region of -15 to -10 [°C], Fb increased with the decrease of the temperature. (iii) Fb dropped off with the decrease of the temperature below -15 [°C]. (iv) At high temperature region of over room temperature, Fb rose with the increase of the temperature.