Development of Electrical Insulation Techniques in Vacuum for Higher Voltage Vacuum Interrupters

In order to develop a higher voltage vacuum interrupter, the development of a high voltage electrical insulation technique is needed. For the enhancement of electrical insulation performance, clarification of the fundamental electrical discharge characteristics in vacuum and at the same time, development of the applied insulation techniques for vacuum interrupter, such as long gap and non-uniform breakdown characteristics in vacuum, etc. are required. In this paper, the recent research activities and new findings on these subjects are reviewed and discussed, in particular, on electrode materials, electrode conditioning for non-uniform fields, surface charging characteristics of solid insulators and electric field optimization techniques