Low Inductance 180KV Switch Development For fastcap technology

A low inductance rail-gap pressurized switch has been developed for FASTCAPI technology. This switch is similar in design to the switches utilized in the SHIVASTAR 9 MJ capacitor bank, and a large part of the design database was drawn from that area of activity. Previous switches utilized on the FASTCAP I base were the SHIVA style rail-gaps mounted externally on one end of capacitor. This technology performed reliably up to 120kV; however, tracking problems occurred at higher voltages. To circumvent this capacitor-switch interface problem, a switch was developed as an integral part of the FASTCAPI assembly. Other features included in the design are REPRATE technology and new rail-gap spacing to accommodate the 190 kV operational rating of the switch. The new switch design is presented along with a method of using the switches in a 360kV FASTCAP I Marx.