AC Breakdown Properties of Vegetable-Oil-Based Insulating Fluid Containing NaCl (Aqueous Solution and Particles)

Abstract

This paper reports AC breakdown properties of the vegetable-oil-based insulating fluid (FR3) contained NaCl aqueous solution and particles. These results were showed as the following. (i) AC electric strength (Fb) of FR3 with 50 to 100 ppm of NaCl aqueous solution showed constant value and 200 ppm of that slight decrease when the concentration of the aqueous solution increased. (ii) When FR3 contained 300 ppm of the aqueous solution, Fb decreased in the concentration of 0 to10 wt%, and turned to rise in 26.4 wt% of that. (iii) Fb increased with adding 1×10^-3 to 2×10^-3 wt% of NaCl particles. (iv) Fb of 400 to 600 ppm water contained FR3 improved substantially with adding more than 1×10^-3 wt% of the particles.