Feasibility Assessment on Vacuum Insulated Switchgear

To find feasible alternatives to the use of SF6 in medium voltage switchgear equipment, AREVA T&D and Tsinghua University has started a cooperation to investigate the feasibility of using vacuum. This paper focused on three main points of the design of the Vacuum Insulated Switchgear (VIS): the maintainability of vacuum system, the insulation performance, and the thermal behavior under operating conditions. In our work, such steps were followed: literature review, basic designs, calculation and analysis. The investigation results showed the feasibility of 40.5 kV/2 kA VIS, assuming that the thermal design and material choice are done carefully in order to fulfill the requirements: insulation rating, life time and rated current. Whereas, for High Voltage switchgear equipment, 126kV or higher voltage level, further experimental research work is still needed. Key-Words: Vacuum Insulated Switchgear; Vacuum insulation; Vcuum lifetime; Vcuum thermal performance