Title :
Influence of polarity and field non-uniformity on the breakdown voltage characteristics of SF6 gas under impulse voltages
Author :
Manjunath, B.S. ; Dwarakanath, K. ; Naidu, M.S.
Author_Institution :
Central Power Res. Inst., Bangalore
Abstract :
A comprehensive study of electrical breakdown in SF6 gas has been carried out under both polarities of lightning impulse (1.2/50 μs) (LI) and switching impulse (250/2500 μs) (SI) voltages over a pressure range of 0.1 to 0.49 MPa, using a rod-plane electrode configuration with various rod diameters (D) of sharp needle, (D≃0 mm), 1.5, 2, 3, 6 and 12 mm and for different gap spacings varying from 10 to 100 mm. Experiments were also conducted using 50 Hz a.c. voltages under the same experimental conditions for different gap spacings of 10 and 20 mm. The influence of field nonuniformity, the polarity and the type of voltage on the breakdown voltage characteristics of SF6 gas have been analyzed. The impulse ratios have been calculated and their variation have been explained in terms of fundamental physical processes
Keywords :
SF6 insulation; electric breakdown; insulation testing; lightning; power system transients; space charge; 0.1 to 0.49 MPa; 1.2 to 50 mus; 1.5 mm; 10 mm; 10 to 100 mm; 12 mm; 2 mm; 20 mm; 250 to 2500 mus; 3 mm; 50 Hz; 6 mm; SF6; SF6 gas; breakdown voltage; breakdown voltage characteristics; electrical breakdown; field nonuniformity; impulse ratios; impulse voltages; lightning impulse; polarity; rod diameters; rod-plane electrode configuration; sharp needle; switching impulse; Breakdown voltage; Corona; Dielectrics and electrical insulation; Electric breakdown; Electrodes; Gas insulation; Geographic Information Systems; Lightning; Needles; Sulfur hexafluoride;
Conference_Titel :
Electrical Insulation, 1994., Conference Record of the 1994 IEEE International Symposium on
Conference_Location :
Pittsburgh, PA
Print_ISBN :
0-7803-1942-7
DOI :
10.1109/ELINSL.1994.401413
