Latest developments in 145 kV gas insulated switchgear

Over twenty five years of service experience has proven the reliability of SF₆ GIS and today, its application, especially in areas of high electrical load density such as towns and industrial centres, is worldwide. The author describes how, in order to meet the latest application specifications, GEC ALSTHOM has recently developed a range of 145 kV GIS, type designated F75. The purpose of this article is to describe, by way of an example, the main design features of the F75 and to demonstrate how present customer requirements influence design parameters of GIS in general