Abstract
In order realize a reliable, compct and economical converter station for HVDC transmission, applications of Gas Insulated Switchgears (GIS) for DC transmission lines are considered. The characteristics of DC gas insulation are different 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 the ±500kV DC-GIS. Electrical and mechanical peformances of these components have been tested and proven to be satisfactory. Finally these components had been assembled into a full DC-GIS and subjected to a long-term voltage endurance test. In this paper, design philosophy of ±500kV DC-GIS, details of the components and the test results are described.
