What are the main differences between dry transformers and o

   

    The biggest difference between oil-immersed transformer and dry-type transformer is that there is no "oil". Since oil is liquid and has fluidity, oil-immersed transformer must have a shell. The inside of the shell is transformer oil. The dry type transformer has no oil, so the outer shell is not used. The coil of the transformer can be seen directly. Another feature is that the oil-immersed transformer has an oil pillow on top, and the transformer oil is stored inside, but now the new oil-immersed transformer also has no oil pillow.

 

All are power transformers, which have iron cores for magnetic circuits and windings for circuits. The biggest difference is between "oil" and "dry". That is to say, the two cooling medium is different, the former is transformer oil (of course, there are other oil such as oil) as the cooling and insulation medium, the latter is air or other gas such as SF6 as the cooling medium. Oil transformer consists of the core and windings of the body in a tank filled with transformer oil. The iron core and winding are sealed with epoxy resin casting coating. There is also a now much used non-encapsulated type, winding with special insulation paper impregnated special insulation paint, etc., to prevent the winding or iron core moisture.

 

For the convenience of heat dissipation of oil-immersed transformer, that is, for the convenience of internal insulation oil flow heat dissipation, a radiator is designed on the outside, just like the heat sink, while the dry transformer does not have this radiator, and the heat dissipation depends on the fan under the transformer coil.

 

Oil-immersed transformers are generally installed indoors or outdoors in separate transformers for fire protection purposes, while dry transformers must be installed indoors and generally installed in distribution rooms.

 

In terms of output and dosage, the current dry variation voltage level is only 35kV, and the capacity is smaller than the oil variation, about 2500kVA. And because the dry transformer manufacturing process is more complex than the same voltage grade and the same capacity oil transformer, the cost is also high. So at the moment, from the point of view of the amount of oil or more. But because of the environmental protection of dry change, flame retardant, impact resistance and other advantages, and often used in indoor and other high requirements of power supply and distribution places, such as hotels, office buildings, high-rise buildings, and so on.

 

It can be seen that the dry transformer and the oil transformer have their own advantages and disadvantages. The oil transformer has low cost and easy maintenance, but it is combustible and explosive. Due to its good fire resistance, the dry transformer can be installed in the load center to reduce voltage loss and power loss. But the dry change price is high, the volume is big, the moistureproof dustproof sex is poor, and the noise is big.

 

Next, let's summarize the differences mentioned above into the following seven points: