Water in oil-filled high-voltage equipment part II: Water content as physicochemical tools for insulation condition diagnostic

Water can be used as a physicochemical tool for insulation condition diagnostics. Dissolved water, even at high concentrations and higher temperatures does not increase dielectric losses as shown in previous investigations. When in emulsion, it increases the dielectric losses at the expense of electrophoresis conductivity. On electric strength, water has a strong influence while bound water can reduce the electric strength of oil by about 40% and increase the dissipation factor by 2 or 3.But when equilibrium conditions to changes in temperature are considered, normalized water contents in oil are negligible. On the one hand, the diagnostics based on water content analysis consist of determining the moisture content of the solid insulation. When temperatures rise, the local partial pressure of water will also rise in addition to the solubility of oil and the relative humidity. This will increase the concentration of dissolved water because of the dissolution of a part of the bound and dispersed water. On a grander scale, the study of the effects of water on oil in transformers can be used for automated decision-making for the tasks in the operative diagnostics of oil-filled equipment such as transformers.