Mathematical Model and Practical Implementation
of Transformer Oil Humidity Sensor
V. F. Hraniak, V. A. Matviychuk, and I. M. Kupchuk
The mathematical dependence of the integral dielectric constant of transformer oil on its humidity is obtained. It is shown that the increase in humidity in the range from 0% to 0.5%, which corresponds to its allowable change, is accompanied by a monotonic increase in the integral dielectric constant along the nonlinear dependence. The design of a high-frequency humidity sensor in the form of a band asymmetric waveguide is proposed, which transforms the latter into a phase shift of the information wave. The mathematical model is developed and the transformation equation is obtained. It has been experimentally established that the total relative error, which consists of the error of this model, the instrumental error of the hard-ware and the subjective error of removing the measured information does not exceed 2%. The article is devoted to solving the problem of reliability of technological equipment and is part of an interdisciplinary study on the development of a set of energy efficient equipment for feed preparation, which is performed on the basis of laboratories of Vinnytsia National Agrarian University.