Study of the temperature conditions of power transformers elements for example transformers at substation «Kabun-І» (Syrian Arab Republic)

Abstract

RELEVANCE. Any device loses its performance over time, Power transformers too. The problems of overheating and insulation are the main influencing factors to the operation status of power transformers. Thus, the study is of high relevance and applied demand, because the heating ofpower transformer elements, especially in the territory of the Syrian Arab Republic, can reach 46 °C. Monitoring the state ofpower transformers is of decisive importance in the study of reliability and safety indicators in the power system. Thermal stress is one of the main parameters to be controlled. Sharp fluctuations in the temperature of the transformer winding, oil, insulating medium, etc. affect the operating conditions, sen’ice life and safety of transformers. PURPUSE. Determination of the type of functional dependences of the heating temperature of windings and oil ofpower transformers on their loading. METHODS. Determination of the type of functional dependences of the change in the temperature of the windings and oil of power transformers using the methods of statistical data processing, approximating functions and assessing their reliability. RESULTS. Approximating functions of the main temperature parameters ofpower transformer elements have been developed - a function of the temperature of the average overheating of the winding above the oil temperature; function of the temperature of the average overheating of the oil above the temperature of the cooling air; oil superheat temperature function above the cooling air temperature; superheat function of the hottest spot above the cooling air temperature. The coefficients of determination of the obtained temperature functions of the average overheating of the winding and the average approximation error are determined. As a result of the research, it was found that the polynomial function is the most reliable. The developed dependencies can be used for practical application to assess and analyze the heating temperature of oil and transformer windings with a known load, as well as to control the operating modes of electrical equipment and consumers of electrical energy in power supply systems.

Keywords

• power transformer
• cooling conditions
• winding temperature
• oil temperature
• load factor