First 800 kV GIS in the World
The first 800 kV GIS was built for the ALPHA installation in ESCOM‘s 800 kV system in South Africa and was handed over to the customer in March 1987. Critical aspects of GIS design for high rated voltages, such as disconnector switching capabilities, transient overvoltages, insulation coordination, electromagnetic interference fields and electro- magnetic compatibility for secondary systems were carefully studied and solved.
The 800 kV GIS demonstrate well the advantages of GIS technology over air-insulated switchgear by ensuring higher safety for the operating personnel, being less sensitive to environmental factors, and requiring less space for its installation.