Title :
DC pre-breakdown phenomena and breakdown characteristics in the presence of conducting particles in liquid nitrogen
Author :
Hara, M. ; Suehiro, J. ; Maeda, H. ; Nakashima, H.
Author_Institution :
Dept. of Electr. & Electron. Syst. Eng., Kyushu Univ., Fukuoka, Japan
fDate :
2/1/2002 12:00:00 AM
Abstract :
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
Keywords :
cryogenics; discharges (electric); electric breakdown; electric potential; electrodes; nitrogen; powders; C; N2; breakdown characteristics; breakdown voltage reduction; carbon powder; cryogenic liquids; free conducting particles; gap. breakdown; heavy contamination; horizontal spacer surface; liquid N2; liquid nitrogen; metallic particle; metallic powder; microdischarge; mm size particles; oppositely charged electrode; point-to-plane gap; pre-breakdown phenomena; uniform field gap; Contamination; Electric breakdown; Electrodes; Fabrication; Fiber reinforced plastics; Nitrogen; Powders; Superconducting coils; System testing; Voltage;
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
