The application of dry-type transformers and oil-immersed transformers in box-type substations
A box-type substation (referred to as "box transformer") is a complete set of equipment that integrates high-voltage switches, transformers, low-voltage power distribution, etc. It is characterized by convenient installation, small footprint, and easy maintenance, and is widely used in urban power grids, industrial parks, and new energy projects.As key voltage transformation devices in the power system, dry-type transformers and oil-immersed transformers have different application scenarios due to their distinct structures and cooling methods. The selection of these transformers should be determined based on the usage environment and requirements, while also considering factors such as load demand and energy efficiency rating.
Dry-type transformers utilize air cooling and do not employ liquid insulating media. They offer advantages such as fire resistance, explosion proofing, environmental friendliness, high safety, and simple maintenance, making them suitable for locations with stringent safety and environmental requirements. However, they have drawbacks including poor heat dissipation, inferior insulation performance, and relatively high noise levels.
It is widely used in urban power grids, high-rise buildings, commercial centers, subways, tunnels, airports, data centers, and densely populated industrial facilities. In addition, in the new energy field, such as photovoltaic power stations and wind farm booster stations, dry-type transformers are also commonly used in the low-voltage side distribution link, especially suitable for indoor installation environments. In fully enclosed box-type transformer enclosures, they are commonly used for small-capacity box-type transformers.
Oil-immersed transformers achieve cooling and insulation through insulating oil, which boasts excellent insulation performance, low noise, good heat dissipation, and strong overload capacity, making them suitable for high-capacity and high-voltage scenarios. However, the use of insulating oil emits harmful substances, posing safety hazards.
It is primarily used in substations, power plants, large industrial enterprises (such as steel, chemical, and mining industries) within the power transmission and transformation system, as well as in long-distance power transmission projects. Due to its excellent economy and stability, oil-immersed transformers occupy a dominant position in the main grid structures of the State Grid and China Southern Power Grid, and are particularly suitable for outdoor locations with ample space and fire isolation conditions. They are not afraid of water and humid environments, such as the standard box-type transformers of the State Grid, which typically have capacities of 400kVA, 500kVA, 630kVA, etc.
In summary, the selection of transformers for box-type substations requires comprehensive consideration of factors such as the usage environment, load demand, and energy efficiency rating, and should be based on actual needs. Before procurement, there are usually electronic drawings drawn by the design unit, which contain detailed specifications. Alternatively, one can directly contact the box-type substation manufacturer for consultation and customization. Common models include S11-M, S13-M, SCB10, SCB11, and SCB13. With the improvement of energy efficiency standards, the s20 and s22 series of high-efficiency oil-immersed transformers and the scb14 and scb18 series of dry-type transformers are gradually being promoted, each playing advantages in energy conservation and consumption reduction, as well as safety and reliability, to meet the development needs of new power systems.
