Vacuum insulator flashover - Mechanisms, diagnostics and design implications

This paper presents an approach for obtaining science-based answers to practical vacuum device problems. The question ''How to translate scientific knowledge to design and operation practice'' is rephrased to the more productive question ''What research activities are required to provide science-based answers to practical problems?'' Such activities involve the study of operational mechanisms in realistic geometries with the help of appropriate diagnostics. Within this framework, recent research developments on vacuum insulator flashover are reviewed, with emphasis on the implications for device performance and design. Secondly, an overview is given of recent research activities, performed at the Eindhoven University of Technology. By studying the relationship between flashover mechanisms and insulator performance, and the relationship between insulator performance and design, we aim at improved device performance, the formulation of guidelines, and the development of device diagnostics, for dc and ac vacuum devices.