Recent activity and future trend on ageing characteristics of electrical insulation in GIS from manufacturer´s view point

The recent activity on electrical insulation and its ageing aspect in gas-insulated switchgear (GIS) as well as future trends are described in this paper. Present status of research shows that although there are a lot of reports on computer based partial discharge measurement, there are few on the intrinsic phenomena of fundamental ageing characteristics. These data will be indispensable for extending new concepts of GIS insulation. As an example, it is pointed out that research on electric stress enhancement in solid materials is important, in particular, in relation to life-estimation and life-control techniques as well as with making more compact GIS. For this purpose, the introduction of consistent concepts, from the development/design stages to the testing/operation stages, of GIS is needed. This concept would include sensor integrated GIS, failure-prediction techniques and stress-controlled life-estimation systems. These proposals are described in this paper from the manufacturer´s viewpoint