Now whether in the city or in the countryside, electricity has become an indispensable source of energy in people's lives, everywhere you can see there are overhead power lines and transformers of different sizes. Electricity in the long-distance transmission, in order to reduce the loss in the line, you have to be in the power plant

Transformers are used to raise the voltage to thousands or even hundreds of thousands of volts. With such a high voltage of electricity obviously can not be used directly to the general industrial machinery and household appliances up, it is necessary to transformer to reduce the voltage to 220 volts, so as to ensure the safety of electricity.

The appearance of the transformer is a kind of outside with many vertical tube container, the container is filled with a kind of petroleum products called transformer oil. As we all know, in order to make the machine can run normally, usually have to add lubricating oil, and there is no moving parts in the transformer at all, why must add transformer oil? Nowadays almost every house has some small transformers which are used to step down the voltage from 220V to 9V, 6V or 3V in order to serve as a power source for some small appliances. You will find that these small transformers are hot during use, sometimes even hot. This is because when a transformer is working, there is always a small portion of electrical energy that is converted into heat. When the transformer is relatively large, the amount of heat energy it releases is considerable, if you do not try to take away the heat, the temperature of the transformer will get higher and higher, and finally the transformer will burn out. In order to solve this problem, people will be used to transform the coil and silicon steel all immersed in transformer oil, with oil to absorb the heat released. When the transformer oil convection flow through the pipe outside the transformer, will be the heat to the surrounding air, so that the transformer can keep the oil temperature is not too high. Thus, the function of transformer oil is not to lubricate, but to act as an intermediary medium to distribute the heat generated by the transformer into the air.

The raw material for the production of transformer oil is a petroleum fraction with a relatively low viscosity, obtained by distillation under reduced pressure. According to the special function of transformer oil, there are also some special requirements for it, the most important of which is its electrical properties. The oil itself in general is not conductive, because the transformer oil is used in high voltage, so it must have very good electrical insulation properties, that is to say, in a very high voltage will not be broken. First of all in the transformer oil is absolutely can not contain water, once there is water transformer may be due to a short circuit and burned. Furthermore, the transformer is a kind of long-term use of fixed equipment, of course, which the transformer oil also want to be able to use for a long time, at least 10 years or even 15 years do not deteriorate, in order to ensure that the power supply is stable and safe. Transformer oil so long with the air and copper and iron and other metal contact, if it is not good antioxidant performance, it will generate acid and water, etc., thus leading to the deterioration of its electrical properties as well as equipment corrosion and other ills. For this reason, the transformer oil need to go through a very strict refining, in order to remove all kinds of harmful components in the oil, at the same time, in order to prevent oxidation, but also have to add some antioxidant additives, in order to extend its service life. Transformers are generally placed in the open air, in order to ensure that it can operate normally in winter, the requirements of the transformer oil freezing point is relatively low, the current transformer oil grade is to its freezing point to the division.

Belong to this category of electrical insulation oil and cable oil and capacitor oil, etc., they are installed in the high-voltage cables and capacitors, play an insulating role.