Purpose of Gas Insulated Substation
Air has a dielectric strength of 33kV/cm. SF6 gas, on the other hand, has a dielectric strength of ~83kV/cm. Naturally, when the live parts are immersed in a pressurized gas chamber they can be placed a lot closer. Every piece of equipment (except the transformer or any other coil product) that makes up a substation can be neatly packed in an enclosed gear that is filled with SF6.
Cost of gas insulated substation
- Single leg/bay of 138kV breaker and a half substation (not including protective relays – equipment only): ~$500,000.
- 345kV gas-insulated bus only: ~$2,600 dollars per feet.
Lead time to procure gas insulated substation
Information on cost and lead time is for your general knowledge only. Contact vendor with your equipment specifications for actual figures.