Importance of oil immersed transformer oil
Writer： Hengfeng you electric Time：2023-04-20 views：times
Importance of oil immersed transformer oil
Oil immersed transformer has been widely used because it has the advantages of faster heat dissipation than dry-type transformer, wide application range, low environmental requirements and low price.
However, due to the presence of oil, it belongs to combustible substances. At the same time, it also has certain pollution.
In order to reduce the fire risk, the oil flash point shall not be less than 135 ℃. Flammable gases such as hydrogen and hydrocarbons will be produced by thermal decomposition or under high voltage. This gas will dissolve in insulating oil, but the flash point will be reduced, even to 52 ℃.
In this way, the fire risk has changed significantly. For large high-voltage transformers, anti gas evolution transformer oil must be used.
The withstand voltage strength of oil is very high in theory. In the experiment, especially pure oil has been tested. Its electrical strength is as high as 4000kv / cm. Impurities, moisture and bubbles are mixed into the transformer oil. The electrical strength actually applied on site is about 200 ~ 250kV / cm.
For example, the water content in oil is about 15ppm (in DL / T596-1996 code for preventive test of power equipment, the water content in oil during operation of 500kV transformer is required to be ≤ 15ppm). However, there is more water in paper insulation, and 2% water can be contained in paper insulation.
Hengfengyou electric recommends that the insulating oil be tested and analyzed regularly and the maintenance be strengthened (once every 3 years).
Prevent impurities from being mixed into the oil and brought into the main transformer, resulting in transformer fault caused by rapid rise of transformer oil dielectric loss in a short time after the transformer is put into operation.
