Torness experience

An indoor 420 kV gas insulated substation (GIS) is installed at the Torness 1300 MW AGR Power Station situated on the east coast of Scotland some 50 km from Edinburgh. The Torness 420 kV 50 kA 4000 A GIS installation consists of an 8 circuit-breaker mesh arrangement with two 660 MW generator connected in-feeds, four cable/overhead line circuits, two of which are `teed´ with a shunt reactor and two 420 kV/145 kV interbus transformers connected directly to the GIS busbars via SF₆ /oil bushings. The operation of the substation is described