Summary

Vacuum circuit breakers are widely used in the medium voltage class, In the vacuum circuit breakers, the late breakdowns sometimes occur after the interruption of current, and these late breakdowns are thought to be triggered by the microparticles. In this paper, the motion of the microparticles and the breakdown triggered by the microparticles are observed under the DC voltage. It turns out that the motion of the microparticles can be grouped into three patterns: attaching to the electrodes, bouncing at the electrodes, bouncing up and down between the electrodes. The patterns of the breakdown triggered by the microparticles can be grouped into 6 patterns according to the motion of the microparticles before/after the breakdown and the place of the breakdown. The acceleration of some microparticles changed during the motion. This implies that the charge of the microparticle changed. The microparticles are positively charged by the secondary electron emission under the bombardment of the field emission electrons from cathode, while they are negatively charged by absorbing the field emission electrons.

Additional informations

Publication type ISH Collection
Reference ISH2017_427
Publication year
Publisher ISH
File size 1 MB
Pages number 6
Price for non member Free
Price for member Free

Authors

DUARTE, WATSCHINGER, KRISPIN, BOUQUEGNEAU

Keywords

vacuum, microparticle, breakdown, Cranberg hypothesis, field emission

Breakdown triggered by microparticle in vacuum gap
Breakdown triggered by microparticle in vacuum gap