||Gas insulated transformer is a transformer which employ SF6 gas as the insulation medium.
Nomenclature of supplies products: Up to 300 kV 400 MVA,
Scope of application:
Insulation / cooling: - sulphur hexafluoride (SF6) with low / high pressure.
Solid insulation material: - mylar film, GAC – film, aramid paper, plate cardboard.
Expansion tank: - not required
On-load tap changer:
- Diversion switch - vacuum interrupter
- Tap changer – roller contact
Free-standing substations, underground substations in urban areas, office buildings, basements of buildings. Gas insulated transformers are installed in environmentally critical areas where oil leakage is prohibited.
• No need to construct special system of oil drains, oil receivers and oil collector;
|• Fire and explosion risks; SF6 gas is non-flammable. Since the rise in tank pressure for an internal fault is very small compared with the GIT tank withstand strength, the GIT tank will not explode .
• Joint system of external, internal and automatic fire fighting;
• Compactness and possibility to install in underground facilities, basements or ground floors: since neither a conservator nor pressure relief arrangement is required, the height of the transformer room can be reduced. For the case of 275 kV / 300 MVA class application, approximately 2 to 2.5 m. reduction in height can be achieved.
• The application of GIT together with GIS does not required a fire wall between the GIT and GIS and this arrangement enables a compact substation to be achieved.
• Efficiency, possibility of heat recovery from heat-transfer unit of GIT for heating up facilities;
• Compliance with ecological requirements, preservation of natural landscape;
• When constructing an underground substation with GI T, above ground may be used for different purposes: park area, office buildings, shops, etc.;
• Cost savings in materials, construction and installation works, current maintenance and operating costs.
|Version of GIT with GIS 110 kV (5 cells)