Fixed Cover Mechanical Endurance Research of Vacuum Interrupter In Open Pole

The fixed cover mechanical endurance of vacuum interrupter (VI) has been investigated in open pole in ring main unit with 0.45bar compression air. The mechanical stress simulation results show that the maximum stress happens in the braze area between fixed cover and fixed rod. The mechanical stress can be reduced by improving the fixed cover shape and braze type. The mechanical endurance of VI can perform over 10000 close open operations in ring main unit. The VI can pass 48kV power frequency test after mechanical endurance test.