Comparison between gas- and air insulated network concepts with the life cycle cost method

Since the liberalization of the energy markets in the late 90s of the last century, the application of gas insulated substation (GIS) becomes more important for the energy supply companies. With the use of gas insulated substations energy supply companies want to reduce their operating and maintenance costs. In this paper a typical German 110-kV transmission and distribution system, which is composed by rural and urban areas, is analysed. For this network the impact of the application of air insulated substations (AIS) and GIS-Substations on the whole system costs is compared. The results depict the main cost-drivers as well as the most important elements of the system. Furthermore, it is shown how costs can be reduced by the application of different maintenance strategies.