Gas-insulated transmission line (GIL)

This paper deals with the recent developments in the application of gas-insulated transmission lines and their applications in the near future to solve power transmission shortages, mainly in metropolitan areas. The main technical data of the GIL used in 420 kV and 550 kV transmission network have been discussed. The GIL is a today available and future orientated technical solution to bring the power transmitted by an overhead line underground without a reduction of power transmission capability, in cases where overhead lines are not possible. This technical possibility is today economical visible and will be used in the near future for high power, long distance transmission lines.