1. Oil-immersed transformer is a common power equipment used to transform the voltage of the high-voltage grid to meet the power supply needs of the low-voltage grid. 2. The working principle of the oil-immersed transformer is based on Faraday's law of electromagnetic induction, that is, in the high voltage side coil of the transformer, due to the high voltage current, the alternating magnetic flux will be generated, thereby inducing a certain electromotive force in the low voltage side coil. 3. Through the joint action of the iron core of the transformer, the conversion of high voltage to low voltage is realized. To provide electricity for cities, industries and rural areas. 4. At the same time, transformers are also widely used in railway, aviation, mining, military and other fields. In short, oil-immersed transformers play an important role in residential life and industrial production. 5. During use, it is necessary to maintain good maintenance and management to ensure its stable work and extend its life.