WHITEPAPER: State of the art in GIS Condition Monitoring and Return of Experience of more than 20 Years plus in GIS monitoring
The electrical industry experienced a change into direction of intelligent electrical energy network technologies and new requirements for stability and reliability of key network components over the last 10 to 15 years. This development still will go on also in the future. Furthermore the developed markets like Europe, US and Japan are facing an aging fleet of key network components, which should be economical and without breakdowns operated till end of its life. Additional to that, also refurbishment programs based on results of diagnostic and monitoring are developed to overhaul aged parts and to extend the life of the key components. After deregulation of the electrical energy market the cost factors gained more importance. In this economic environment, methods of intelligent network wide monitoring are gaining more and more attention. Principles of condition based maintenance are used more widely. Integrated concepts of online condition monitoring, severity analyses and condition assessments as well as cost efficiency modelling and simulation are seen today as solutions for an efficient equipment and network utilization and determining to a great extent the development in the field of diagnostic and monitoring of electrical equipment. The basic monitoring principles, the main drivers to implement monitoring and the comprehensive monitoring approach will be discussed for GIS (Gas Insulated Switchgear). Partial discharge activity, gas density and breaker conditions are the main parameters for a GIS, which allow an assessment of its condition. After more than 20 years of GIS monitoring experiences (especially for PD), a number of case studies are showing its efficiency. Due to the above described changes in the technical and political environment, condition monitoring as basis for an effective condition based maintenance is gaining more and more importance.