What is the significance of transformer oil filtration?

Under the action of heat and electric field, the transformer oil in contact with oxygen is gradually oxidized to various oxides, alcohols, aldehydes, acids, etc. and finally insoluble colloids and sludge are formed. These acidic substances reduce the insulation properties of the transformer, so the transformer oil needs to be filtered. And do an exhaust gas treatment. The gas influences the insulating properties of the insulating oil.

• What is the significance of transformer oil filtration?

• What parameters should be considered for transformer oil filtration?

• What is the principle of transformer oil filtration?

What is the significance of transformer oil filtration?

Transformer oil is the most important insulating and cooling medium of oil transformers. Its electrical strength and chemical composition directly affect the performance of transformers. If the oil contains a small amount of moisture and impurities, the puncture resistance will be reduced; and the oil is slightly oxidized and deteriorated upon contact with oxygen at high temperatures. Therefore, the transformer oil should be filtered when the transformer is installed.

To prevent safe operation from being affected by deterioration of oil quality, regular oil samples from the power distribution should be tested and analyzed in normal operation and the oil should be processed according to the analysis results. The inspection period for the oil-chemical monitoring of the energy distribution operation shall be prescribed at least once every three years.

What parameters should be considered for transformer oil filtration?

Flash point

Its limit is below 130°C. Or 5°C lower than the previous test value. There are 2 possible reasons for exceeding the limit value: there is a local overheating error in the device; wrong oil. If the flash point limit is exceeded, the following countermeasures can be taken: identify the cause and eliminate the fault; Perform degassing treatment of the vacuum oil filter or perform oil change treatment.

outer shape

If the oil looks opaque, visible impurities or suspended matter are present. If the oil color is too dark, the oil will look abnormal. Possible reasons for the abnormal appearance are: the oil contains moisture, fibers, soot and other solids. For oil with abnormal appearance, the following countermeasures should be taken: If the oil is blurred, cloudy and white, this indicates that the oil contains water, and the water content should be checked. If it is found that the oil contains carbon particles, the oil color is black, or even has a burnt smell, it may be that there is an arc or partial discharge error inside. It should be combined with other tests to determine the cause and eliminate the error. If the oil color is dark and the color of the oil has changed greatly, you should pay attention to whether the aging of the oil is accelerated, which can be combined with the acid value analysis of the oil, or strengthen the monitoring of the operating temperature of the oil.

What is the principle of transformer oil filtration?

In transformer oil filtration, the oil enters through the inlet into the primary filter under the action of the internal and external pressure difference, and the large impurities are filtered out. The fog is first formed in the device, and then the film is formed, so that the contact surface in the vacuum is enlarged by a hundredfold of the original, and the moisture in the oil is quickly absorbed under the conditions of high heat vacuum, large surface area and high absorbency. Evaporated and discharged by vacuum system.

CTBU has been a university and state-owned state-owned enterprise since 1990 (at the beginning of 1983 we were a research and development center of our own university). The main business is the manufacture and service of oil treatment machinery, vacuum pump systems, air dryers, SF6 systems and some testing equipment.