IMPROVEMENT OF TRADITIONAL METHODS OF TESTING INSULATION OF SUBSTATION TRANSFORMERS

Abstract

Typical methods of analysis of insulation parameters and processes of degradation of protective properties of windings of current-carrying parts of power transformers, electric machines, apparatuses and other electrical equipment are considered. It is shown that almost all insulation materials (oil, plastics, paper) are subject to moisture and contamination by their decomposition products under the influence of various external factors. In order to detect these defects in dynamics in a timely manner and to prevent sudden breakdowns of electrical insulation, periodic monitoring and testing of insulation is carried out. The analysis of traditional methods of testing and evaluating the state of isolation of transformers by applying a constant voltage is presented. The main causes and errors of changing the insulation parameters during temperature fluctuations are revealed. A new methodology for analyzing the measurement of the frequency characteristics of dielectrics is proposed, which makes it possible to adequately and accurately transform the results of the evaluation of insulation parameters in the frequency range as a function of temperature. The results of the research are implemented in systems and devices for complex diagnostics of substation equipment transformers.