Reliability forecasting model for power transformers that have fulfilled their standard service life

Today, the urgent tasks of the heat and power industry of the Russian Federation, as many other countries, are the problem of exceeding the service life of high-voltage electrical equipment of transformer and traction substations. This state of affairs leads to adverse consequences in the electric power system, which directly reduces the reliability of power supply to consumers, as well as to increase operating costs and technical losses of electric energy. Under the maximum load of transformers that have fulfilled the standard service life, constant monitoring is required to develop recommendations on the operation and operation modes of power transformers. The article considers the issue of calculating the reliability of power oil transformers. According to the collected statistical information, the most damaged parts of power transformers are identified. The main indicators that characterize the level and condition of the power transformer windings are shown. Using quantifiers of the distribution of the Chi-square, the upper and lower limits of the time between failure of the windings of power transformers for different periods of operation are determined, confidence limits with probability α = 0.9, 0.95, 0.99 are determined. According to the obtained data, the distribution of the Chi-square received a failure flow of the main element - the windings of power transformers with different periods of operation. There is a linear dependence of the decrease in reliability of the power transformers depending on the period of operation.