What is the qualified value standard for dry-type transformers

The qualified value standard for dry-type transformers is determined by the insulation level. For example, when using H-grade insulation materials, the maximum operating temperature is 180 ℃, and the maximum temperature rise should be less than 125K. These standards ensure the safe operation and stable performance of transformers.

As an important equipment in the power system, the qualified value standard of dry-type transformers is the key to ensuring safe and efficient operation. These standards mainly involve the temperature rise limit of transformers, which is closely related to the insulation level of transformers.

1、 Insulation level and temperature rise limit

According to the national standard GB6450-1986, the insulation levels of dry-type transformers are divided into A, E, B, F, H, and C. Transformers with different insulation levels have varying limits on their maximum operating temperature and maximum temperature rise.

1. A-level insulation: The maximum working temperature is 105 ℃, and the maximum temperature rise should be less than 60K.

2. E-class insulation: The maximum operating temperature is 120 ℃, and the maximum temperature rise should be less than 75K.

3. B-class insulation: The maximum working temperature is 130 ℃, and the maximum temperature rise should be less than 80K.

4. F-class insulation: The maximum operating temperature is 155 ℃, and the maximum temperature rise should be less than 100K.

5. H-level insulation: The maximum working temperature is 180 ℃, and the maximum temperature rise should be less than 125K. This is the insulation level currently used by most dry-type transformers.

6. C-level insulation: The maximum working temperature is 220 ℃, and the maximum temperature rise should be less than 150K.

2、 The Importance of Qualified Value Standards

The qualified value standard for dry-type transformers is not only a measure of product quality, but also a key factor in ensuring the safe operation of the power system. The temperature rise limit, as a core indicator, directly affects the service life, performance stability, and safety and reliability of transformers.

During the operation of transformers, if the temperature rise exceeds the specified limit, it may cause insulation material aging, performance degradation, and even lead to electrical faults and safety accidents such as fires. Therefore, strictly adhering to the qualified value standards is crucial to ensure the normal operation of dry-type transformers.

In addition, the qualified value standard also provides important basis for the design, manufacturing, selection, and use of transformers. Manufacturers need to produce according to standard requirements, while users need to choose the appropriate transformer model and insulation level based on actual needs.

In short, the qualified value standard for dry-type transformers is the key to ensuring their safe and efficient operation. All relevant parties should fully understand and follow these standards to ensure the stable operation and safe reliability of the power system.