Title :
Breakdown of SF6 in non-uniform field gaps under combined DC fast oscillating impulse and standard lightning impulse voltages
Author :
Siodla, K. ; Kuffel, E. ; Fujinami, H.
Author_Institution :
Dept. of Electr. & Comput. Eng., Manitoba Univ., Winnipeg, Man., Canada
fDate :
4/1/1993 12:00:00 AM
Abstract :
Breakdown and voltage-time characteristics of nonuniform field gaps in compressed SF6 gas were studied using a point-to-plane electrode arrangement. Combined voltages, consisting of very fast transient (VFT) overvoltage and standard lightning impulse (SLI) voltage superimposed upon DC voltage, were applied. The experimental gas pressure ranged from 100 to 500 kPa. The results presented show that the magnitude and the polarity of the direct voltage, as well as the gas pressure, influence the corona discharge and the breakdown characteristics. It was found that the breakdown voltages under the VFT are higher than the corresponding values obtained under SLI voltages. At the higher gas pressures, the voltage-time characteristics of VFT fall below those for SLI
Keywords :
corona; electric breakdown of gases; gaseous insulation; impulse testing; insulation testing; overvoltage; sulphur compounds; 100 to 500 kPa; DC fast oscillating impulse; DC voltage polarity; breakdown characteristics; breakdown voltages; compressed SF6 gas; corona discharge; gas pressure; nonuniform field gaps; point-to-plane electrode arrangement; standard lightning impulse voltages; very fast transient overvoltage; voltage-time characteristics; Breakdown voltage; Contamination; Dielectrics and electrical insulation; Electric breakdown; Electrodes; Gas insulation; Geographic Information Systems; Needles; Sulfur hexafluoride; Voltage control;
Journal_Title :
Electrical Insulation, IEEE Transactions on
