Analysis on the special properties of insulating oil of oil-immersed transformer
Time：2025-04-18 Auther：ZTelec-www.ztelectransformer.com
In modern power systems, oil-immersed transformers are the core equipment for maintaining stable power transmission. As the “blood” of transformers, insulating oil plays an irreplaceable role in ensuring the safe and efficient operation of the transformer due to its unique properties. In-depth exploration of the special properties of insulating oil is of great significance to improving the reliability and safety of the power system.
The key role of insulating oil in transformers
Oil-immersed transformers use insulating oil as a dual medium for insulation and cooling. During the operation of the transformer, whether it is normal working conditions or sudden failures, insulating oil shoulders the heavy responsibility. Its performance is directly related to the electrical and thermal performance of the transformer, which in turn affects the insulation strength, heat dissipation efficiency and service life of the transformer.
The core special properties of insulating oil
Dual functional properties
Insulating oil plays a dual key role inside the transformer. First, it achieves efficient cooling through circulating flow to maintain the operating temperature of the transformer in a reasonable range; second, it builds a reliable insulation barrier to provide necessary insulation protection for the equipment and ensure the safety of power transmission.
Excellent electrical insulation performance
In power transformers, insulating oil is not an ordinary filling material. Its electrical insulation performance under high voltage is the key. Since the molecular structure of pure insulating oil is stable, there are very few free electrons, and it is difficult for conductive channels to form. This makes the transformer oil have extremely high insulation strength and can withstand high voltage without breakdown. When the transformer is running, it effectively isolates the high-voltage winding from the low-voltage winding, the winding from the iron core and other components, avoiding short circuits and grounding faults. It is a solid line of defense to ensure the safe operation of the transformer.
Excellent thermal conductivity
Insulating oil has a high specific heat capacity and thermal conductivity, which gives it excellent heat absorption and transfer capabilities. When the transformer winding heats up, the insulating oil quickly transfers and dissipates the heat to the surrounding environment through convection and conduction mechanisms, so that the internal temperature of the transformer is stabilized within the normal range. Good heat dissipation performance significantly improves the overload capacity and operation reliability of the transformer.
Excellent chemical stability and aging resistance
During long-term operation, insulating oil will inevitably undergo oxidation reactions with oxygen in the air to generate acidic substances and precipitates. High-quality insulating oil can effectively slow down the oxidation process and extend its service life with its good antioxidant stability, which is mainly attributed to the antioxidants added in it. The antioxidants capture free radicals, interrupt the oxidation chain reaction, and protect the molecular structure of the insulating oil from being destroyed.
Economic and environmentally friendly characteristics
Transformer oil has become the first choice for insulation and cooling media for most power transformers due to its abundant natural reserves and low price. Although it is flammable and harmful to the human body, its cost advantage, good heat dissipation effect and low maintenance cost make it widely used in various power scenarios.
Efficient arc extinguishing performance
When an arc fault occurs in a transformer, insulating oil can quickly extinguish the arc. Under high temperature, insulating oil decomposes to produce a large amount of gas, and the expansion and impact of the gas can effectively blow out the arc. At the same time, its high insulation strength can also prevent the arc from reigniting, ensuring the safe operation of the transformer.
The special properties of insulating oil in oil-immersed transformers involve multiple dimensions such as electrical, chemical, and physical. These properties are interrelated and work together to ensure the safe and stable operation of the transformer. A comprehensive and in-depth understanding of the characteristics of insulating oil will help make more scientific and reasonable decisions in the design, manufacturing, operation, and maintenance of transformers, which promotes the power system to move towards higher reliability and safety.
