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 kV

Rated current: 2500 A – 4000 A

Transmission capacity: 1000 MVA – 3800 MVA

Rated short-time current: 63 kA/3s

Rated Frequency: 50/60Hz

Capacitance: 55pF/m

Inductance: 220nH/m

Resistance: 10mW/km (typical)

Insulation gas: N2-SF6 mixture

Pipe 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