In recent years, the development of dry-type transformers has continued to heat up. The rapid development speed will bring different changes to the dry-type transformer industry.
The overload capacity of a dry-type transformer is related to the ambient temperature, the load condition before overload (initial load), the insulation and heat dissipation of the transformer, and the heating time constant. If necessary, the overload curve of the dry-type transformer can be obtained from the manufacturer.
At present, the annual output of resin-insulated dry-type transformers in China has reached 10,000MVA. With the promotion and application of SC(B)9 series with low noise (distribution transformer noise below 2500KVA has been controlled within 50dB) and energy saving (no-load loss reduced by 25%), the performance indicators and manufacturing of dry-type transformers in China have reached an advanced level. With the popularization and application of dry-type transformers, its manufacturing technology has also achieved considerable development. It can be predicted that the future dry-type transformers will be further developed in the following aspects.
(1) Energy saving and low noise: With the new low-consumption silicon steel sheet, foil winding structure, stepped core joints, environmental protection requirements, in-depth noise research, and computer optimization design and other new materials, new processes, and new technologies The introduction will make future dry-type transformers more energy-efficient and quieter.
(2) High reliability: Improving product quality and reliability will be the unremitting pursuit of people.
(3) Environmental protection characteristics certification: Based on the European standard HD464, conduct research on the characteristics of weather resistance (C0, C1, C2), environment resistance (E0, E1, E2) and fire resistance (F0, F1, F2) of dry-type transformers And certification.
(4) Large-capacity: From dry-type transformers based on 50～2500KVA distribution transformers to 10000～20000KVA/35KV power transformers, as the urban power load continues to increase, the urban network regional substations are getting deeper and deeper into the city For load centers such as central areas, residential communities, large factories and mines, 35KV large-capacity power supply transformers for community centers will be widely used.
(5) Multifunctional combination: From a single transformer to a multifunctional combined transformer with air cooling, protective casing, temperature computer interface, zero sequence transformer, power metering, closed bus and side outlet.
(6) Multi-field development: From distribution transformers to special transformers and multi-purpose fields such as power station auxiliary transformers, excitation transformers, subway traction rectifier transformers, high-current electric furnace transformers, nuclear power plants, marine and oil production platforms, etc. Among them, dry-type traction transformers used in urban subways and rail transit have three voltage levels of 10, 20 and 35KV, and capacities of 800, 2500 and 3300KVA. In order to reduce harmonic pollution, the rectification has been developed from 12 pulses to 24 pulses. Rectification: The exciting transformer of the 840,000KW generator of the Yangtze River Three Gorges, which has attracted worldwide attention, has been successfully developed by Shunte Factory and passed the acceptance. It can be predicted that the 21st century distribution transformer will be a resin insulated dry-type transformer with superior performance, low noise and energy saving.