NEWS CENTER

Corporate culture

Industry News

Knowledge popularization

Advantages and disadvantages of dry-type and oil-immersed transformers, as well as selection guidelines

Release time:

2023-09-14

In our daily life, there are two common types of transformers: oil-immersed transformers and dry-type transformers. Generally, we see more oil-immersed transformers outdoors, while dry-type transformers are often found indoors. However, the transformers selected are different for different needs and usage places. Here, I will briefly introduce the advantages and disadvantages of dry-type transformers and oil-immersed transformers for your reference.

Generally speaking, when both can be used, dry-type transformers are chosen. A dry-type transformer is a completely static, solid-state device that requires less maintenance to provide trouble-free service. Oil-type transformers need to be designed in a special transformer room for placement, and low-voltage closed busbars or dense busbars need to be connected to the low-voltage incoming cabinet.

However, the cost of dry-type transformers will be a little more expensive than oil-immersed transformers, and there are also differences in capacity: dry-type transformers generally have a capacity of less than 1600KVA, a voltage of less than 10kV, and some reach a voltage level of 35kV; oil-immersed transformers can be used from small to large. To reach full capacity, the voltage level can also reach all voltages.

From a structural point of view, oil-immersed transformers have good heat dissipation performance. However, these two transformers follow different standards and have different temperature rise requirements, so they cannot be compared across the board. Dry-type transformers are usually used indoors where fire protection requirements are relatively high. When an oil-immersed transformer fails, fuel injection and combustion accidents may occur, which needs to be taken into consideration.

Guidelines for the selection of power transformers: At present, for the selection of power transformers. Mainly refer to GB/T 17468-2088 "Guidelines for Selection of Power Transformers" and GB4208-2008 "Enclosure Protection Level (IP) Code" for reference. It is necessary to take the overall reliability of the transformer as the basic principle and comprehensively consider the advancement, rationality, economy and other factors of the technical parameters. In addition, the possible impact on system safety, environmental protection, material saving, transportation, installation space and other aspects must also be considered.