In the operation of transformer, when the winding passes through the current,there will be core loss and winding resistance loss. These losses will lead to the transformer heating and insulation deterioration. It affects the output and life of transformer. It has become an important measure to improve the capacity of transformer by improving its heat dissipation capacity.
What kinds of cooling media are commonly used in transformers
The cooling medium of transformer is determined by the form of transformer.
1. Dry-type transformer is cooled by external air, so its cooling medium is air.
2. The cooling medium of oil-immersed transformer is transformer oil and silicone oil, among which transformer oil is mainly divided into 25 # and 45 # oil insulation. Nowadays, some energy-saving and environmental-friendly transformers, especially foreign transformer plants, adopt silicone oil and other new types of insulation oil and silicone oil.
Selection of Transformer Cooling Mode
According to the requirements of transformer selection guidelines, the selection of cooling methods is recommended as follows:
Products with capacity less than 31500KA and rated voltage less than 35KV;
Products with capacity less than 50000KA and rated voltage less than 110KV.
12500 kVA ~ 63000 kVA, 35kV ~ 110kV products;
Products with capacity less than 75000KA and rated voltage less than 110KV;
Products with capacity less than 40000KA and rated voltage less than 220KV;
3. Forced Oil Circulation Air Cooling
50000-90000 kVA, 220 kV products.
4. Forced Oil Circulation Water Cooling
Generally, the boost transformer of hydroelectric power plant is 220kV or above, 60MVA or above.
5. Forced Guided Oil Circulation Air-cooled or Water-cooled (ODAF or ODWF)
Products with capacitymore than 75000KA and rated voltage is 110KV;
Products with capacity more than 120000KA and rated voltage is 220KV;
Products with rated voltage is 330KV and 500KV.