SEMINAR REPORT ON “GAS INSULATED TRANSFORMER”

Submitted By:-CHANDAN KUMAR SINHA

[1222004]

NATIONAL INSTITUTE OF TECHNOLOGY PATNA

ELECTRICAL ENGINEERING (POWER SYSTEM)

18-02-2014

SF6  GAS INSULATED TRANSFORMER

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

NATIONAL INSTITUTE OF TECHNOLOGY PATNA

18-02-2014

CONTENTS

SF6 ---AN OVERVIEWGAS PROPERTIESAPPLICATIONS OF A GAS INSULATED

TRANSFORMER(GIT)FEATURES OF A GITLAYOUT COOLING APPARATUS OF A GAS

INSULATED TRANSFORMERDIFFERENCE BETWEEN OIT $ GITCONCLUSION

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18-02-2014

SF6 – AN OVERVIEW SF6 or sulfur hexafluoride gas molecules are

combined by one sulfur and six fluorine atoms

S + 3F2 = SF6 + 262 KCal.

Each sulphur atom in SF6 molecule creates covalent bond with 6 fluorine atoms.

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18-02-2014

SF6 GAS PROPERTIES

It is colourless, odourless, 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 eco-friendly and not poisonous. It can be recycled.

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18-02-2014

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.

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18-02-2014

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.

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LAYOUT OF A GAS INSULATED TRANSFORMER

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Oil immersed transformer

Gas insulated transformer

Insulation/cooling Insulating oil SF6 gas(Pressure 0.14 or 0.43MPa-g(20ˆ))

Solid Insulation Material

Oil Impregnated Paper, Pressboard

PET Film,PPS Film, Aramide Paper, Pressboard

Conservator Necessary Unnecessary

18-02-2014

NATIONAL INSTITUTE OF TECHNOLOGY PATNA

Difference between oil immersed transformer and gas insulated transformer

Pressure rise on internal fault

Significant tank pressure increases do not occur during internal failures due to the Gas characteristics. The risk of a tank explosion or fire incident can be completely eliminated.

NATIONAL INSTITUTE OF TECHNOLOGY PATNA

18-02-2014

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.

NATIONAL INSTITUTE OF TECHNOLOGY PATNA

18-02-2014

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.

NATIONAL INSTITUTE OF TECHNOLOGY PATNA

18-02-2014

REFERENCE

http://www.electrical4u.com/sulfur-hexafluoride-sf6-gas-properties/http://www.engineeringtoolbox.com/refrigerants-d_902.htmlhttps://www.toshiba.com/ind/data/tag_files/GIT_Brochure.pdf

18-02-2014

NATIONAL INSTITUTE OF TECHNOLOGY PATNA

Thank you

NATIONAL INSTITUTE OF TECHNOLOGY PATNA

18-02-2014