Dielkometrical Transformer Oil Humidity Sensor

Abstract

It is known that water is part of the vast majority of organic and inorganic materials. Materials formed in natural conditions or obtained in the production process, as a rule, contain a certain amount of water in their composition, the mass fraction of which depends both on the ability of the material to absorb (sorb) or retain on the surface (adsorb) water, and on the conditions, in which this phenomenon takes place. Moisture content significantly affects the physical and electrical properties of non-metallic materials, including transformer oil. In particular, the increase in moisture content in the latter not only significantly reduces its dielectric strength, creating prerequisites for a breakdown between the current-carrying parts of transformers, oil switches and other equipment that involves its use. Regular measurements of the humidity of transformer oil are an essential component of the maintenance of a whole group of electrical equipment. And since nowadays the transition from planned maintenance to on-demand maintenance is becoming more and more widespread, it can be concluded that the development of means of controlling the humidity of transformer oil, which would be suitable for high-precision express measurement or work compatible with control systems in the mode real time is an actual scientific and applied problem. The article proposes the construction of a transformer for measuring the dielectric loss tangent angle of transformer oil, which is characterized by increased metrological characteristics and is suitable for real-time operation. The value of the tangent of the dielectric loss angle of the transformer oil measured with the specified measuring transducer, being related to the humidity of the latter by the corresponding functional dependence, can be used for the analytical determination of the latter. A mathematical model of the dielectric angle tangent measuring transducer has been developed, on the basis of which both the sensor conversion equation and other metrological characteristics can be estimated.