Investigation of Moisture Removal in Vegetable-based Electrical Insulating Oils using Glycerin

This study examined the removal of water in vegetable-based electrical insulating oils using glycerin. The effects of the amount of glycerin addition on the removal of 600 ppm distilled water contained in the oil were examined, and the following conclusions were reached. (1) The amount of water in the rice ester oil decreased after the addition of glycerin, and amount of moisture decreased more when the amount of glycerin that was added increased. (2) The kinematic viscosity of the rice ester oil was almost constant regardless of the amount of glycerin added. (3) The volume resistivity of the rice ester oil enhanced by the elimination of moisture in the rice ester oil. (4) The AC breakdown strength of rice ester oil tended to increase with increasing the amount of glycerin added.