Development and design of DC‐GIS

In order to realize a reliable, compact, and economical converter station for HVDC transmission, applications of gas insulated switchgear (GIS) for dc transmission lines are considered. The characteristics of dc gas insulation differ from those of ac. The behavior of metallic particles left in the enclosure is one of the largest differences. The accumulation of electrical charges on solid insulators is another essential factor in designing a DC-GIS. Also, degradation of metal oxide arrester blocks under dc stress must be deliberated. Based on the fundamental studies, we developed the components of ± 500-kV DC-GIS. Electrical and mechanical performances of these components have been tested and proven to be satisfactory. Finally these components have been assembled into a full DC-GIS and subjected to a long-term voltage endurance test. In this paper, the design philosophy of ± 500-kV DC-GIS, details of the components, and the test results are described. © 1999 Scripta Technica, Electr Eng Jpn, 129(2): 51–61, 1999