This seminar report discusses gas insulated transformers, which use sulfur hexafluoride (SF6) gas instead of oil as both an insulating and cooling agent. SF6 has excellent dielectric and cooling properties and is nonflammable, nontoxic, and recyclable. Gas insulated transformers are advantageous as they have a smaller footprint, higher reliability, and cause no pollution. They are suitable for applications like hospitals and underground facilities where fire safety is important. The report outlines the features, layout, cooling apparatus, and accessories of gas insulated transformers and concludes that ongoing research is improving their efficiency and making power systems more reliable and safe.

1. SEMINAR REPORT
ON
“GAS INSULATED
TRANSFORMER”

2. SF6 GAS INSULATED
TRANSFORMER
EMPLOYS SF6 GAS
INSTEAD OF THE
CONVENTIONAL
OIL BOTH AS AN
INSULATING AND
COOLING AGENT.

3. CONTENTS
SF6---AN OVERVIEW
APPLICATIONS OF A GAS INSULATED
TRANSFORMER
FEATURES OF A GAS INSULATED
TRANSFORMER
LAYOUT
COOLING APPARATUS OF A GAS
INSULATED TRANSFORMER
IMPORTANT ACCESSORIES
CONCLUSION

4. SF6 – AN OVERVIEW
 SF6 is Sulphur hexafluoride formed by chemical
reaction of molten sulphur and fluorine.
 It is colorless, odorless, nonflammable, non-
corrosive and chemically stable.
 High dielectric strength.
 Quenches arc effectively and has excellent
cooling properties.
 Good thermal conductivity and excellent thermal
stability.
 It’s not poisonous and eco-friendly.
 It can be recycled.

5. APPLICATIONS OF SF6 GAS
INSULATED TRANSFORMER
 Hospitals, underground shopping centers,
substations where a high level of fire
safety is required.
 Water treatment plants and hydroelectric
power plants where waterways must be
kept unpolluted.
 Thermal power plants, chemical plants,
public works facilities etc where high
reliability is required.

6. FEATURES OF A GAS
INSULATED TRANSFORMER
Highly flame resistant and non explosive.
High resistance to moisture.
Reduced installation space.
High reliability.
Causes no pollution.
Explosion proof tank.
Easy inspection and maintenance work.

7. LAYOUT OF A GAS
INSULATED TRANSFORMER

8. Pressure rise on internal fault

9. CONSTRUCTIONAL
FEATURES
Constructional
Features
Oil Immersed
Transformer
(OIT)
Gas Insulated
Transformer
(GIT)
Insulation/Cooling Insulating Oil SF6 (Pressure 0.14 or
0.43MPa-g)
Solid Insulation
Material
Oil Impregnated Paper,
Pressboard
PET Film, PPS Film,
Aramide Paper,
Pressboard
Conservator Necessary Unnecessary
On Load Tap
Changer
Arcing Switching in
Oil
Vacuum Interrupter

10. COOLING APPATARTUS
 Employs a cooling medium
in liquid phase such as a
Refrigerant R113
otherwise known as
Trifluorotrichloroethane
or C2F3Cl3.
 SF6 gas is obviously used
as the second cooling
medium.

11. IMPORTANT ACCESSORIES
DIAL THERMOMETER PRESSURE GAUGE
TEMPERATURE COMPENSATING
PRESSURE SWITCH

12. CONCLUSION
 Incessant research and continuous
developments have made construction of
large capacity gas insulated transformer
possible.
 With the eco-friendly aspects of SF6 gas and
considering the huge advantages of the gas,
long strides can be made in this regard to
further utilize it and increase the efficiency of
the transformer and making the power system
more reliable and safer.

13. Thank you for a very patient
hearing.