What is the role of transformer oil transformer oil performance requirements

Transformer oil is widely used in transformers and circuit breakers and other equipment, such as various types of Distribution transformer. Its main components are alkanes, naphthenic saturated hydrocarbons, aromatic unsaturated hydrocarbons and other compounds. Commonly known as square oil, light yellow transparent liquid, relative density of 0.895. Freezing point <-45 °C. What are the functions and properties of transformer oil ? Let's learn to see it soon.
Transformer oil performance requirements

1. The viscosity should be moderate, too large will affect the convection heat, too small will reduce the flash point.
2. The pressure oil density is as small as possible to facilitate the precipitation of moisture and impurities in the oil.
3. The flash point should be as high as possible and generally should not be lower than 136°C.
4. The fixing point should be as low as possible.
5. The lower the content of impurities such as alkali, sulfur, and ash, the better so as to avoid corrosion of insulating materials, wires, fuel tanks, etc. as much as possible.
6. The level of degree can not be too high. The degree of oxidation is usually expressed in terms of acid value, which means the amount of potassium hydroxide (mg) required to absorb the free acid in 1 g of oil.
7. A set of not too low, the stability of the test acid value usually indicates a precipitate, which represents the ability of the oil aging transformer oil which effect


(1) Insulation: Transformer oil has much higher insulation strength than air. Immersion of insulating material in oil not only increases the dielectric strength but also protects it from moisture.
(2) Heat dissipation: The specific heat of transformer oil is large, and it is often used as a coolant. The heat generated during the operation of the Power Transformer causes the oil near the core and the windings to increase in thermal expansion. Convection through the upper and lower parts of the oil causes the heat to be dissipated through the radiator to ensure normal operation of the transformer.
(3) Arc suppression: In the oil circuit breaker and transformer on-load pressure regulating switch, arc will be generated when the contact is switched. Due to the good thermal conductivity of the transformer oil, and under the high temperature of the arc, a large amount of gas can be contacted to generate a large pressure, thereby improving the arc extinguishing performance of the medium and enabling the arc to extinguish quickly.
There are usually the following requirements for the performance of transformer oils:

(1) Transformer oil density is as small as possible to facilitate the precipitation of moisture and impurities in the oil.
(2) Viscosity should be moderate, too large will affect convection heat dissipation, too small will reduce the flash point.
(3) The flash point should be as high as possible and generally should not be lower than 136°C.
(4) The freezing point should be as low as possible.
(5) The lower the content of impurities such as acids, alkalis, sulfur, and ash, the better so as to avoid corrosion of insulating materials, wires, fuel tanks, etc. as much as possible.
(6) The degree of oxidation should not be too high. The degree of oxidation is usually expressed in terms of acid value, which means the amount of potassium hydroxide (mg) required to absorb the free acid in 1 g of oil.
(7) The stability should not be too low. The stability is usually expressed by the precipitate of the acid value test. It represents the ability of the oil to resist aging. Conclusion: The transformer oil was introduced for everyone, and we hope to help everyone. For more relevant knowledge, please continue to pay attention to this website information platform. Follow-up will present more exciting content for everyone.