Gas Insulated Substation Defined

Gas insulated substations help deliver electricity more efficiently.

A gas-insulated substation, or GIS, consists of electricity-conducting components and a grounded metal housing. Gas acts as the insulator between the live, electrical parts and the grounding. A substation extends an electrical grid.

Details

Compressed sulfur hexaflouride gas, designated SF6, is used in a GIS. At atmospheric pressure, the ability of the gas to insulate materials from electricity is about three to four times that of air. SF6 gas is colorless, nontoxic and chemically inert.

Advantages

A GIS uses a quarter to a tenth of the space of a conventional electrical substation, which makes it ideal for urban areas where space is at a premium. It also requires less maintenance than its conventional counterpart requires.

Influence

Since the first GIS was delivered in 1967, the technology has driven other advances. Circuits can be made smaller since the gas is a better insulator. The components within the substation are also laid out in a more compact arrangement.

References

• Gas Insulated Substation: ScribMD presentations; R. Rajmohan
• Distribution Substations: ABB Gas Insulated Distribution Substations