According to the statistics and analysis of the defects of Ertan Hydropower Station’s 500 kV gas insulated switchgear(GIS) occurred in the past 12 years
the main types of the defects and their incidences are summarized.Accordingly
some preventive measures are provided
such as adopting advanced and maintenance-free equipment
improving maintenance process and quality of equipment
and so on.In addition
the methods for effectively finding defects and reducing defect incidence are discussed.