What is the difference between a dry-type transformer and an oil-immersed transformer?

Comparative analysis of dry-type transformers and oil-immersed transformers What are the differences between the

At present, the application of dry-type transformers and oil-immersed transformers is more widely used in construction projects. Because of the characteristics of the project, the power transmission also has high requirements. One needs to try to avoid waste in the process of power transmission, on the other hand, also need to improve the safety of power transmission process.

First, oil-immersed transformers and the basic characteristics of dry-type transformers      

#Oil Immersed Transformer

Oil-immersed transformer is a kind of transformer with transformer oil as the heat dissipation medium, in the process of power transmission and distribution, this kind of transformer has a long history of application, due to the structure of this kind of transformer is relatively simple, so both in the manufacture and operation of a high degree of convenience.

#Dry Type Transformer     

Dry-type transformers do not require the use of transformer oil as a cooling medium compared to oil-immersed types, but utilise air. Due to its oil-free character, the requirements for the fire resistance rating of the building are relatively small. For some special building environments, only this kind of dry-type transformer can be used. And with the current continuous development of insulating materials, the application range of this transformer is further increased, compared with the oil-immersed type, it has the advantages of worry-free, dust-proof, non-flammable, and small local power.

Second, the advantages and disadvantages of oil-immersed transformers and dry-type transformer comparison      

Advantages of dry-type transformer over oil-immersed transformer

      From the operating principle of dry-type transformer, mainly through the air convection this feature to complete the cooling work, and the overload capacity will also be affected by different factors, such as temperature, load force, time and so on. Specific advantages can be divided into the following points      One is this kind of transformer has no oil and non-flammable, reduce the risk of combustion in the application process, for fire prevention aspects of the capital investment will also be greatly reduced, and this kind of transformer will not appear in the case of oil leakage, so it does not need to be too close inspection.

      Secondly, the dry-type transformer is a kind of work without hanging decorations, the physical height of the room will be further reduced, thus saving the project cost. Thirdly, when installing the transformer it can be installed together with the low voltage distribution equipment, reducing its construction footprint and saving even more space.

      Dry-type transformer relative to the disadvantages of oil-immersed transformers

      The dry-type transformer also has its corresponding disadvantages. One of the two transformers compared to the epoxy resin material heat dissipation is relatively poor, but its heat dissipation function is not balanced. Secondly, the temperature measurement of this transformer is fixed, but the measured temperature is only the local temperature, not the average temperature. And the measuring substance is only the insulating oil, but due to its fluidity characteristics, the average temperature is measured. Third, the insulation of oil-immersed transformers is also better, after the damage can not be fully restored, and epoxy resin is also easy to aging, resulting in further degradation of its insulation, and in this case, once the failure will lose the value of repair. Fourth, for the dry-type transformer, its manufacturing process is also more complex, the production cost is much higher than the oil-immersed transformer. Fifth, when the oil-immersed transformer after the end of life, some of its components can be recycled and reuse, but relatively speaking, the use of dry-type transformer after the end of life value is relatively low, and can not be recycled.

Third, the oil-immersed transformer and dry-type transformer economic benefit comparison

      Outdoor installation

      With the current application of the two kinds of transformers more and more widely, but for the same amount of power and voltage of the two kinds of transformers, in the manufacture of price and application of the effect but there is a relatively large difference. According to relevant statistics, the two kinds of transformers in the market price comparison, its ratio is generally between 3.01 to 1.44. And in the manufacturing process, as the capacity of the transformer increases, the ratio between the two prices will be further reduced. The installation of the transformer is determined by measuring the current carrying capacity of both devices. Oil-immersed transformers are comparatively much less costly than outdoor installation of both transformers. The difference is mainly due to the high manufacturing cost of dry-type transformers, and in the manufacturing process to ensure that there is a high degree of insulation of the shell, and both sides need to use the cable to connect, so the installation cost is also higher. For oil-immersed transformers, because of its own low cost, and in the high-voltage side only need to use relatively cheap copper and aluminium for connection. Therefore, if this type of dry-type transformer is connected outdoors, the temperature will affect its own temperature due to the temperature, so that the use of smaller capacity pre-assembled substations.

      Indoor installation

      For indoor installation work, dry-type transformer is relatively good economy, but because of the economy of this type of transformer, and the special structure, so in the indoor installation needs to be placed in the same room with other equipment. In addition to the site can also be set up in the low-voltage cabinet, so that the transformer shell can be close to the side of the cabinet. In addition, the low-voltage side of the dry-type transformer needs to be connected to the low-voltage cabinet, using the copper wire way to connect. But the oil-immersed transformer has a special situation, when the 10KV oil-immersed transformer, its capacity is 80KV-A, and the weight will be more than 100kg, so need to set up a separate room, and can not exist with the equipment at the same time, need to try to install in the room. This limitation leads to higher installation costs. There are also special cases, such as oil-immersed transformers and low-voltage cabinets, where other transformer rooms are used as intervals, so the cost of the aluminium cables between the two is also increased. As a result, the installation cost of oil-immersed transformers in the indoor installation process is significantly higher than that of dry-type transformers.

Four, conclusion

      From the analysis of the characteristics of the two transformers, the two transformers each have the corresponding advantages and disadvantages, and from the economic benefits of the two transformers, mainly from the outdoor installation and indoor installation of the two aspects of the analysis, the installation of the different locations, the cost required are not the same.

Xuzhou Pengcheng Electric Co., Ltd. is the main dry-type transformer, oil-immersed transformer transformer manufacturers, if you need to feel free to consult my plant's various transformer models and quotations.