Estimation ofContact material inVacuum Circuit Breaker

Inorder toevaluate theperformance ofa vacuumcircuit breaker, we haveinvestigated measurement ofchopping current andtheir related values, andnon-sustained disruptive discharges (NSDD) byusingAgWC25,AgWC35,CuW-SbandCuCr electrodes. We havemeasured thecurrent chopping phenomena andoptical spectroscope measurement and their decay ofneutral metal atcurrent chopping, anda kindofdielectric strength NSDDofvacuuminterrupter. As results, thegenerating frequencies ofNSDD, CuW-Sbelectrode isthelowest valueandtheir performance whencircuit breaker isoperated inthe system isverygoodbecause oflowvoltage switching surge. On thecontrary AgWC35electrode wasthe highest value anditsperformance forswitching would givetheworstcondition. After thetest, weobserved electrode surface andwefound outmetallic protrusion ofthesurface ofAgW-Sbwasrelatively large. Forthe choppingcurrent, we observedspectroscopic measurement atcurrent chopping foraneutral vapor andtherate ofchange ofdecay atcurrent chopping was verymuchrelated andmoreoverchopping current for AgWC35 wasthelowest valueamongthetested electrode material. r =~ ~ ~ ~ ~ ~~ 0000.