Oil-immersed distribution transformers of 11KV and 33KV
This transformer is designed for power systems with a rated voltage ≤20kV and frequency of 50Hz. It is specially developed for distribution applications in industries such as petroleum, metallurgy, chemical, textile, and light industry, as well as in environments with high dust levels.
1. Core Made of high-permeability grain-oriented cold-rolled silicon steel sheets, featuring a fully slanted joint laminated structure. The core columns are designed with multi-step circular cross-sections, and the yokes share the same cross-section as the core, ensuring uniform magnetic flux distribution and low no-load loss. 2. Windings Constructed with corrugated oil ducts and a non-impregnated process, tightly bound with tension bands for robust mechanical strength. Concentric coil arrangement; the high-voltage winding includes taps for voltage regulation, connected to an off-circuit tap changer mounted on the tank cover. Voltage adjustment must be performed with the power supply disconnected.
3. Safety Protection Devices Pressure relief valves are standard for transformers rated 30–2000 kVA. Gas relays with alarm and tripping terminals can be installed upon customer request.
4. Oil Temperature Monitoring Devices All transformers are equipped with sockets for glass thermometers on the tank top, with probes extending 120±10 mm into the oil. Transformers rated 1000–2000 kVA are additionally equipped with outdoor-type signal thermometers for remote monitoring.
5. Tank and Sealing Technology The tank is constructed with corrugated walls and finished with durable powder coating. The corrugated radiators provide both cooling and volume compensation ("breathing" function), allowing elastic expansion and contraction with oil temperature changes. This design eliminates the need for a conservator, reducing overall height. Vacuum oil-filling technology is used during sealing to completely remove internal moisture and ensure total isolation of the transformer oil from air. This significantly delays insulation aging and eliminates the need for regular oil sampling tests.
