GAS INSULATED TRANSMISSION LINE(GIL)

WHAT IS GIL

• Gas Insulated Transmission Lines (GIL) are a means for bulk

power transmission at extra high voltage (EHV).• the first installation of GIL in 1975, second

generation GIL has been developed• GIL is installed in combination with Gas Insulated Switchgear (GIS), compact solutions can be delivered in order to supply large amounts of electric power

DATA OF GIL

Rated voltage: 230 kV – 550 kVRated current: 2500 A – 4000 ATransmission capacity: 1000 MVA – 3800 MVARated short-time current: 63 kA/3sRated Frequency: 50/60HzCapacitance: 55pF/mInductance: 220nH/mResistance: 10mW/km (typical)Insulation gas: N2-SF6 mixturePipe materials: Aluminium alloys

LAYING METHODS OF GIL

• ABOVEGROUND INSTALLATION:

GIL installation aboveground is a trouble-free option, even for extreme environmental conditions.

high transmission power can be achieved with above ground installation.

LAYING METHODS OF GIL

• VERTICAL INSTALLATION:

Gas-insulated tubular conductors can be installed without a problem at any gradient, even vertically.

They can be installed in a tunnel or shaft.

LAYING METHODS OF GIL

• TUNNEL INSTALLATION:

they can be installed in a tunnel or shaft.

The system stays accessible for easy inspection and high transmission capacity is ensured.

LAYING METHODS OF GIL

•DIRECT BURIAL:

These systems are coated with a continuous polyethylene layer.

the land can be returned to agricultural use with very minor restrictions once the system is completed.

ADVANTAGE

• GIL in tunnels has a very low environmental impact compared to other transmission methods.

• GIL is highly efficient.

• GIL is extremely reliable.

• GIL is affordable.

• GIL emits little heat or electromagnetic radiation.

ADVANTAGE• High transmission capacity.

• Low transmission losses.

• Low capacitance.

• High operational safety (no fire risk, no external impact in

case of internal failure).• No practical ageing of components

(long lifetime).

FUTURE APPLICATION

• Long Distance AC-GIL.

• TransEuropean Networks.

• Offshore Windfarms.

• Improved Reliability of Electric Power. Supply of Cities.

CONCLUSION