Determination of temperature distribution on windings of oil transformer based on the laws of heat transfer

Object of research: development of a technology for determining the temperature of the winding of a power oil transformer, in particular, the analysis of thermal processes in the winding of a power transformer during short-term overloads, taking into account the influence of the environment. Investigated problem: temperature distribution in the winding of a power oil transformer taking into account short-term load surges in the problem of assessing the residual life of the insulation of the transformer winding by temperature aging. The calculation of the temperature distribution in the winding was carried out using the passport data and characteristics of the power oil transformer, including the winding, transformer oil, load currents. Main scientific results: a mathematical model was calculated, with the help of which the results of temperature distribution in the transformer winding were obtained during short-term load surges or constant work with an increased load. According to the presented model, the analysis of the cooling time of the transformer winding after short-term overloads is carried out. Comparing the results obtained on the simulation model with the known results of experimental studies of the temperature distribution in the winding of a power transformer, the adequacy of the mathematical model is proved. It is shown that the use of the laws of heat transfer in a homogeneous plate to analyze the temperature distribution in the transformer winding is not wrong, but requires clarifications and simplifications. The area of practical use of the research results: enterprises of the machine-building industry and energy companies specializing in the production and operation of transformer equipment. Innovative technological product: simulation model of heat distribution in a transformer winding, which can take into account the load of the transformer, the effect of the environment on the insulation of the transformer windings. An innovative technological product: a method for diagnosing the duration of the non-failure operation of a transformer, which makes it possible to ensure trouble-free operation and save money for the repair of transformer equipment. Scope of application of the innovative technological product: design and development of diagnostic systems for windings of power oil transformers

The study of health and quality of operation of the transformer equipment electrical systems

Detection of defects at an early stage of their occurrence, especially for power transformers that have worked out the standard term, is an acute problem. This article discusses the possibility of using the system of monitoring, control and diagnosis of transformer equipment (SMUID) electrical systems in conjunction with the automated control system of electrical equipment (ASU ETO) and automated information-measuring system of commercial electricity metering (AIIS KUE) with the use of QR-code, as well as using TeamViewer for the operational elimination of accidents and identify abnormal operation of transformer equipment. Transformer monitoring system is designed for monitoring isolation, recording and analysis of partial discharges, monitoring of technical condition ensuring maximum fault-free service life of transformers. In addition, the introduction of automated diagnostics and electrical equipment is a necessary condition for the introduction of SmartGrid technology in industrial electric networks, contributes to the reduction of capital investments in the renewal of the equipment fleet. The methods currently used do not detect dangerous insulation degradation, are not sensitive to its aging, and in some cases mistakenly assess the isolation condition. The work analyses the operability and quality of the systems under consideration, shows the hierarchical structure of SMUID. By applying the proposed idea with the QR-code, it is possible to speed up the process of searching for information about the current technical state of electrical equipment.

Adaptive management of technical condition of power transformers

Ensuring reliable operation of power transformers as part of electric power facilities is assigned to the maintenance and repair system, whose important components are diagnostics and monitoring of the technical condition. Monitoring allows you to answer the question of whether the transformer abnormalities and how to do they manifest, while diagnostics allow determining the nature, the severity of the problem, determine the cause and possible consequences. The article presents the results of the authors ' research on creating an algorithm for adaptive control of the technical condition of power transformers using diagnostic and monitoring data. The developed algorithm implements the decision-making procedure for ensuring the reliable operation of oil-filled transformer equipment as part of the substations of electric power facilities. The decision-making procedure is based on the method of statistical Bayesian identification the states of a transformer based on the results of dissolved gas analysis (DGA) in oil. The method is characterized by high reliability of recognizing defects in the transformer and the ability to adapt the probabilities of the obtained solutions to the newly received diagnostic information. These results illustrate the effectiveness of the developed approach and the possibility of its application in the operation of oil-filled transformer equipment.

Assessment of the Efficiency of Transformers Technical Condition Monitoring Based on Dissolved Gas Analysis

The method of analysis of gases dissolved in oil is one of the most informative methods for early detection of defects in power oil-filled transformers. This determined its wide application in the practice of off-line and on-line monitoring of transformer equipment. In the article, based on the ratio of weight coefficients used in the calculation of the technical condition index of functional units and equipment units, a method for determining the reliability of oil-filled transformer equipment is proposed. An indicator that characterizes the quantitative measure of the diagnostic value of a single method (group of methods) for monitoring parameters of a power oil-filled transformer in the calculations of the technical condition index is obtained. The efficiency of monitoring the state of a power oil-filled transformer was evaluated based on the results of the analysis of gases dissolved in oil. A quantitative example of calculating the economic effect of increasing the operational reliability of a group of 110 kV power transformers in one of the areas of the distribution network using a remote diagnostic monitoring system based on the analysis of gases dissolved in oil is given