Oil-immersed distribution transformers 11KV, 22KV, 33KV, 35KV
Fully Sealed Oil-Immersed Transformers are suitable for power systems with AC 50Hz and rated operating voltages of 20kV and below. They serve as distribution transformers in industries such as petroleum, metallurgy, chemical, textile, light industry, and in environments with high levels of dust.
1. Core The core is made of high-permeability grain-oriented cold-rolled silicon steel sheets. It features a modern design with fully staggered joints and a laminated structure. The core columns have a multi-step circular cross-section, and the yoke is of equal cross-section to the core.
2. Windings The windings employ a corrugated oil duct design and are manufactured using a non-impregnation process, secured with tension tape. All windings are concentric coils. The high-voltage winding includes taps corresponding to the required voltage regulation, which are connected to a tap changer. The tap changer is mounted on the tank cover and can only be adjusted after the power supply is disconnected.
3. Safety Protection Devices Transformers with capacities ranging from 30 to 2000 kVA are equipped with pressure relief valves. Gas relays with alarm and trip terminals can be installed based on customer requirements.
4. Oil Temperature Measurement Devices All transformers are fitted with sockets for glass thermometers, located on the top of the tank and extending 120±10 mm into the oil. Transformers with capacities from 1000 to 2000 kVA are equipped with outdoor signal thermometers.
5. Transformer Tank The transformer tank is constructed with corrugated walls and features a durable powder-coated surface. The corrugated radiators not only provide cooling but also function as "breathing" elements. Their elasticity compensates for volume changes in the transformer oil caused by temperature fluctuations. As a result, fully sealed transformers do not require an oil conservator, reducing the overall height of the transformer. During sealing, the transformer undergoes vacuum oil filling, which completely removes moisture from the unit. The transformer oil is isolated from air, effectively preventing the intrusion of oxygen and moisture. This design minimizes the risk of reduced insulation performance and oil aging, thereby eliminating the need for regular oil sample testing.
