To meet the demands of fast closing switch under medium voltage and high current circumstances

a 40.5 k V triggered vacuum switch of high current capacity is designed for medium voltage level application. To meet the need of 80 k A peak current capacity

the switch is applied with multi-rod system to enlarge its burning area so as to increase its working lifetime. To meet the demands of 40.5 k V insulation

the electrode is chambered and a shield is designed to improve the electric field distribution in the switch and its insulation level. A trigger system is designed for the switch with output of 50 k V pulse voltage and trigger current of 3 k A to reliably trigger the switch. The prototype of the designed switch has passed the test of short current impulses of 80 k A peak and 15 ms width for 20 times with trigger delay less than 15 μs. The switch has also passed the withstand power frequency withstand test and the lightening impulse withstand test before and after the short current test while maintaining its high insulation level.