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Difference between Dry-type Transformer and Oil-immersed Transformer

time:2020-01-14 14:17:15 Author:

Here introduce the difference between dry-type transformer and oil-immersed transformer,the oil transformer is a device composed of an iron core and a winding. In an oil tank full of transformer oil. Dry transformers often encapsulate the iron core and wi

What is the difference between dry-type transformer and oil-immersed transformer?  "Of course, the same is that power transformers will have iron cores for magnetic circuits and windings for circuits. The biggest difference is between" oil "and" dry ". That is to say, the cooling media of the two are different. The former uses transformer oil (of course, other oils such as beta oil) as the cooling and insulation medium, and the latter uses air or other gases such as SF6 as the cooling medium. The oil transformer is a device composed of an iron core and a winding. In an oil tank full of transformer oil. Dry transformers often encapsulate the iron core and windings with epoxy resin. There is also a much more non-encapsulated type. The windings are impregnated with special insulating paper. Insulation varnish, etc., to prevent the winding or iron core from being dampened. In terms of output and usage, the current dry-transformer voltage level is only 35kV, and the capacity is relatively small compared to oil transformers, about 2500kVA. Compared with oil transformers of the same voltage level and capacity, it is more complicated and the cost is higher. So at present, the amount of oil is more. However, it is often used indoors because of the environmental protection of dry change, flame retardant, impact resistance and so on. Contour requirements Power supply and distribution sites, such as hotels, office buildings, high-rise buildings, and so on.

Oil-immersed transformers and dry-type transformers each have their own advantages and disadvantages. Oil transformers are low in cost and easy to maintain, but they are flammable and explosive. Due to its good fire resistance, dry transformers can be installed in the load center area to reduce voltage loss and power loss. However, dry transformers are expensive, bulky, have poor moisture and dust resistance, and are noisy.
Dry transformer
Oil-immersed transformers are gradually withdrawing. With dry change, dry change can be disassembled and transported, cleaned, easy to maintain, no machine base is required for installation, no oil seepage pond, etc. It is relatively easy to distinguish from the appearance:
The biggest difference between oil-immersed transformers and dry-type transformers is the presence of "oil". Because oil is liquid and has fluidity, oil-immersed transformers must have a shell. The inside of the shell is transformer oil, and the transformer is immersed in oil. The coil of the transformer cannot be seen from the outside; the dry-type transformer has no oil, so there is no need for the shell, and the coil of the transformer can be directly seen; another feature is that the oil-immersed transformer has an oil pillow on the inside, which is stored inside Transformer oil, but now new oil-immersed transformers also have transformers without oil pillows;
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The oil-immersed transformer is designed for the convenience of heat dissipation, that is, for the convenience of the internal insulating oil to flow and dissipate heat. The heat sink is designed externally, just like a heat sink, but the dry-type transformer does not have this heat sink. The fan is a bit like an indoor unit for a home air conditioner;
Oil-immersed transformers are generally installed in a separate transformer room or outdoor due to the need for fire prevention, while dry-type transformers must be installed indoors. Generally, they are installed in low-voltage power distribution rooms and installed side-by-side with low-voltage power distribution cabinets. This is the difference between dry-type transformer and oil-immersed transformer,now you know about it.