1100 kV substation - basic design/specifications of GIS for UHV AC and its verification test and site

In Japan, to satisfy the steadily increasing demand for electricity in urban areas, 1100 kV substation equipment have been developed, and a part of the 1100 kV transmission lines were constructed. 1100 kV substations would be located in the mountainous areas, so they must be made as compact as possible to meet installation space constraints and to harmonize with the natural environment. Thus, 1100 kV substations adopt Gas Insulated Switchgear (GIS) as the main circuit from transmission line entrance to transformer bushings. Because the substation is one of the most important items in a 1100 kV system, the equipment in 1100 kV substations requires to be of extremely high reliability. Additionally, various technologies that have not been used in 500 kV and lower systems are applied. To establish carefully the 1100 kV equipment technologies, TEPCO constructed a UHV Equipment Test Station (in the 500 kV Shin-Haruna substation), which has the minimum component of a 1100 kV substation-3 single-phase transformers (3000 MVA bank) and 1 bay of GIS (8000 A). Connecting these facilities to the actual grid in 1996, a field verification test has been carried out. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.