What oil should be added to the oil-immersed transformer？

Oil-immersed transformer is an indispensable and important equipment in power system, its main function is to convert electric energy from one voltage level to another voltage level through the principle of electromagnetic induction. The normal operation of the oil-immersed transformer is inseparable from its internal oil, which not only plays the role of insulation, cooling, lubrication and protection, but also directly affects the performance, life and safety of the transformer. Therefore, it is very important to choose the right oil-immersed transformer oil.

First, the main types of oil-immersed transformer oil

Oil-immersed transformers usually use the following types of oil:

Mineral oil: Mineral oil is the most commonly used transformer oil for oil-immersed transformers, which comes from natural petroleum and is processed by distillation, refining and other processes. Mineral oil has good insulation properties, cooling properties and lubrication properties, and the price is relatively low, so it has been widely used. However, mineral oil also has some shortcomings, such as flammable, explosive, easy oxidation, etc., need to strengthen safety management and maintenance during use.

Silicone oil: Silicone oil is a synthetic oil, synthesized from organosilicone compounds. Silicone oil has high insulation properties and thermal stability, can be stable in high temperature environment. In addition, silicone oil also has lower toxicity and volatility, and has less impact on the environment. However, the price of silicone oil is relatively high, and in some special applications may not meet the requirements.

Ester oil: Ester oil is a synthetic oil made from ester compounds, which has good insulation properties and thermal stability. Compared with mineral oil, ester oil has lower toxicity and environmental impact, and has a higher flash point and is not easy to explode. However, the price of ester oil is also relatively high, and under certain conditions may react with water, resulting in a decline in oil quality.

Bio-oil: Bio-oil is a renewable oil, usually made from vegetable or animal oils. Bio-oil has good insulation properties and environmental friendliness, which can reduce dependence on non-renewable resources. However, the thermal stability of bio-oil is poor, and it is easy to oxidation and decomposition in high temperature environment, so it is necessary to strengthen monitoring and maintenance during use.

Second, the selection principle of oil-immersed transformer oil

When choosing oil-immersed transformer oil, the following factors need to be considered:

Transformer voltage level and capacity: Different voltage levels and capacity of transformers have different requirements for oil quality. In general, the higher the voltage level and the larger the capacity of the transformer, the higher the requirements for oil insulation performance and thermal stability.

The operating environment of the transformer: The operating environment of the transformer is also an important factor in choosing oil quality. For example, transformers operating in harsh environments such as high temperature, high humidity, and dust need to choose oils with good insulation properties and thermal stability.

Transformer requirements: Different transformers have different requirements in the use of the process, such as the need to frequently start and stop the transformer needs to choose the oil with good lubrication performance; Transformers that need to run for a long time need to choose oils with good thermal stability and oxidation resistance.

3. Filling and replacement of oil-immersed transformer oil

In the use of oil-immersed transformers, it is necessary to fill and change the oil quality regularly. Note the following when filling and replacing oil:

Select the right oil: Select the right oil according to the type of transformer, voltage level, capacity and use environment and other factors.

Ensure that the oil is clean: Before filling and replacing the oil, ensure that the oil is clean to avoid contaminants such as impurities and water entering the transformer.

Follow the operating procedures: When filling and replacing the oil, follow the operating procedures to ensure the safe and reliable operation process.