Title :
Area and volume effects on breakdown strength in liquid nitrogen
Author :
Goshima, H. ; Hayakawa, Naoki ; Hikita, Masayuki ; Uchida, Kazunori
Author_Institution :
Nagoya Univ.
fDate :
6/1/1995 12:00:00 AM
Abstract :
We measured dc and ac breakdown voltages in liquid nitrogen (LN 2) with a sphere-to-plane electrode configuration. Experimental results revealed that the breakdown voltage in LN2 did not increase monotonously but partially decreased as the sphere diameter increased at a constant gap length. Thus, the existence of the area and the volume effects on the breakdown voltage in LN2 was verified quantitatively; the breakdown strength decreased when increasing the {SEA}90 (90% stressed electrode area) and the {SLV}90 (90% stressed liquid volume). By changing the experimental conditions, it was verified that both area and volume effects, having a mutual correlation, simultaneously lead to the degradation of the breakdown strength in LN2. In order to examine the area and the volume effects for the larger {SEA}90 and {SLV}90, we also measured the breakdown voltage with a coaxial cylindrical electrode. It was concluded that the dc and ac breakdown strengths in LN2 decreased as the {SEA}90 and the {SLV}90 increased varying widely from 100 to 105 mm2 and from 10 -1 to 105 mm3, respectively
Keywords :
dielectric liquids; electric breakdown; electric strength; nitrogen; AC breakdown voltage; DC breakdown voltage; N2; area effects; breakdown strength; coaxial cylindrical electrode; constant gap length; liquid N2; sphere diameter; sphere-to-plane electrode configuration; stressed electrode area; stressed liquid volume; volume effects; Area measurement; Breakdown voltage; Coaxial components; Degradation; Electric breakdown; Electrodes; Nitrogen; Sea measurements; Voltage measurement; Volume measurement;
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
