dc pre-breakdown phenomena and breakdown characteristics in the presence of free conducting particles in liquid nitrogen are studied experimentally. The results show that a microdischarge occurs when a charged particle is approaching an oppositely charged electrode. An intense microdischarge can trigger a complete breakdown of the gap. The breakdown voltage of a uniform field gap with a free metallic particle of mm size might be reduced well below that of a point-to-plane gap without a particle in liquid nitrogen. Heavy contamination by a metallic powder produces a large reduction in the breakdown voltage, with a horizontal spacer surface. However carbon powder is less hazardous compared to metallic powder.
|Number of pages||8|
|Journal||IEEE Transactions on Dielectrics and Electrical Insulation|
|Publication status||Published - Feb 1 2002|
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering