What Are The Characteristics Of A Fully Sealed Oil-Immersed Transformer?

Because the fully sealed transformer isolates the contact mode between oil and air, the insulation is not affected by moisture, and the aging rate is greatly reduced. Thus, the reliability and service life of the transformer are improved.
No need to check the core before operation, saving costs. In addition to the advantages of the transformer core, coil and body, the following processes and structures are different: The body uses vacuum oiling to completely remove moisture and air from the insulation material to ensure the long-term service life of the transformer.
The oil tank adopts corrugated oil tank or expansion radiator to cancel the oil storage tank. Changes in the amount of fuel are adjusted and compensated by the elasticity of the tank. Transformer oil should be completely isolated from air and sunlight to avoid transformer oil oxidation and moisture, in order to slow down the aging speed of transformer insulation, reduce the daily maintenance and repair of the transformer, and extend the service life of the transformer.
The key technology of fully sealed transformer is to solve the problem of volume change caused by thermal expansion and cold contraction of transformer oil. During the operation of the transformer, the temperature change can reach about 100 ° C, and the volume change of the transformer oil can reach about 0.7%. Ordinary small and medium-sized oil-immersed transformers are equipped with an oil storage tank with an oil-sealed moisture absorber.
The transformer is connected to the atmosphere through the moisture absorber, but the moisture absorption effect of the silica gel in the moisture absorber is limited, and the humid air in the atmosphere will inevitably enter the transformer oil, resulting in the aging of the transformer oil and the reduction of insulation strength. Therefore, users need to frequently replace silicone and handle transformer oil, and need to spend a lot of energy on regular maintenance and overhaul of the transformer.