How Water Affects the Properties of Insulating Liquids

Water has a great influence on the properties of insulating liquids, but this influence does not always have the same impact on the insulation system. Depending on what kind of insulating liquid is used the influence can be more or less. Liquids with a higher water absorption and adsorption capacity are less susceptible to changing liquid properties compared to insulating liquids like mineral oil. This paper provides results of how properties of viscosity, refractive index, breakdown voltage and moisture equilibrium in transformer paper-liquid systems change in relation to the water content.