The work is devoted to the study of a power transformer based on chromatographic analysis of dissolved gases in oil. Data were obtained on dissolved gases (hydrogen, methane, ethane, methylene, acetylene) of power oil transformers of various brands with operation for more than 30 years. Particular attention is paid to the graphical presentation of the results of chromatographic analysis of the oil. As a result, the probable expected defects of power transformers were determined. Studies have shown that power transformers need immediate repair based on their assessment. Timely repair of power oil transformers allows increasing their durability and reliability of power supply to consumers.

Oiled power transformers and autotransformers 40-60 years ago are still in operation in Uzbekistan. At the same time, diagnostic methods for determining faults in transformers and autotransformers remained the same. This article partially analyzes the factors affecting the oils of power transformers and autotransformers used in the agricultural sector. It is known that transformer oil performs the functions of cooling and insulation. During use, the oil is in direct contact with air through the respiratory system. There is a process of transition of moisture and various gases in the composition of the air into the composition of the oil. By the composition of gases, it is possible to determine the reasons for the deterioration in the quality of the main and additional insulation of oil-immersed power transformers. The issues of influence on the state of insulation of marsh gases appearing inside (at the bottom) of the tank of oil transformers and partial discharges in oil-gas medium have been little studied.