Vacuum Interrupter Design for HV and VHV Applications

Presently there is an upsurge in interest in the use of vacuum interruption at transmission voltages (< 100kV). This is due mainly to environmental concerns over the use of SF6 gas, which is today the dominant technology for switching applications at these high voltages. Vacuum interruption has dominated the medium voltage range of switchgear (< 52kV) for many years, and it would appear logical to try to apply vacuum interruption technology to these higher voltage ranges. However applying existing vacuum interrupter technology to higher voltages is not straightforward and there are a number of technical and economic factors to be taken into account. There is some history of applying vacuum interruption to these high voltages and a second paper at this conference (ibid.) deals with this experience and the reasons why this technology was not universally adopted at the time