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Dry type, oil immersed type, inflatable type: Which type of test transformer should be selected?

:2024-05-20 16:34:22:

In the power system, experimental transformers play a crucial role, with a wide variety and unique characteristics. Among them, dry, oil immersed, and inflatable test transformers are known as the "Three Musketeers of Test Transformers" due to their unique performance and use. So, how should we choose these three types of test transformers?

Dry type test transformers, oil immersed test transformers, and inflatable test transformers are all important equipment used for high-voltage testing in power systems, but their working principles, structures, and application scenarios are different. Here is a brief introduction to these three types of test transformers:

1. Dry test transformer:

① Principle: Dry test transformers do not use liquids (such as oil) as insulation and cooling media, but instead use solid insulation materials (such as epoxy resin) to wrap the coils to achieve electrical insulation.

② Structure: usually composed of high-voltage winding, low-voltage winding, insulation material, iron core, and outer shell. Due to the absence of liquid media, the structure of dry-type transformers is relatively simple, and installation and maintenance are also more convenient.

③ Application: Suitable for indoor environments, especially in situations where fire and explosion prevention are required. In addition, due to the absence of oil pollution issues, dry-type transformers are also suitable for some environments with high environmental requirements.

2. Oil immersed test transformer:

① Principle: The oil immersed test transformer uses transformer oil as the insulation and cooling medium. Transformer oil not only has excellent electrical insulation performance, but also effectively reduces the temperature of the coil and improves the operating efficiency of the transformer.

② Structure: usually composed of high-voltage winding, low-voltage winding, iron core, oil tank, oil conservator, oil level gauge, radiator, etc. The structure of oil immersed transformers is relatively complex, but they have high electrical performance and stability.

③ Application: Suitable for high-voltage testing of outdoor and large-scale power systems. Due to its high electrical insulation and heat dissipation performance, oil immersed transformers are suitable for long-term, high load operation.

3. Inflatable test transformer (also known as SF6 gas insulated transformer):

① Principle: The inflatable test transformer uses inert gases such as SF6 (sulfur hexafluoride) as the insulation medium. SF6 gas has excellent electrical insulation performance and chemical stability, and can maintain stable electrical performance in high voltage and high temperature environments.

② Structure: Similar to oil immersed transformers, but with SF6 gas as the insulation medium. Inflatable transformers typically have a smaller volume and weight, making them suitable for situations with high space requirements.

③ Application: Inflatable test transformers are mainly used in situations that require high electrical insulation performance and environmental protection requirements, such as nuclear power plants, subways, urban power grids, etc. In addition, due to the low flammability of SF6 gas, inflatable transformers are also suitable for situations with high fire protection requirements.

When selecting a test transformer, users should consider the actual needs and application scenarios comprehensively. For example, in situations where fire and explosion prevention are required, dry-type test transformers are preferred; In situations where low cost and fast boosting are required, oil immersed test transformers have more advantages; In situations where high insulation strength and long service life are required, inflatable test transformers are the best choice. In summary, users need to comprehensively consider factors such as specific application scenarios, electrical performance requirements, and environmental conditions.


The ZC-501A series oil immersed test transformer is particularly suitable for conducting insulation strength tests on various high-voltage electrical equipment, electrical components, and insulation materials under power frequency or DC high voltage in power systems, industrial and mining enterprises, scientific research departments, etc. It is an essential and important equipment in high-voltage testing.

Kvtester Electronics Technology Co.,Ltd. is a high-tech enterprise specializing in power testing, testing, research and development, production, and sales of testing equipment. It has been engaged in the electrical testing industry for many years, and its products are of high quality. We welcome customers to come and purchase. Service hotline: 0086-27-81778799, to learn more, visit the official website:

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