DocumentCode :
1226082
Title :
Toepler´s spark law in a GIS with compressed SF6-N2 mixture
Author :
Singha, Santanu ; Thomas, M. Joy
Author_Institution :
Dept. of High Voltage Eng., Indian Inst. of Sci., Bangalore, India
Volume :
10
Issue :
3
fYear :
2003
fDate :
6/1/2003 12:00:00 AM
Firstpage :
498
Lastpage :
505
Abstract :
This paper deals with the experimental measurements and analysis of the formative time lags to breakdown and an estimation of the Toepler´s constant for gas gaps, under the application of 50 Hz AC voltage. The experiments were carried out in a 145 kV gas insulated system (GIS) bus duct with pure N2, pure SF6 and SF6-N2 mixture as insulating media. The formative time lags to breakdown in the gas gaps were measured using a fast response capacitive sensor. Toepler´s spark law has been used to explain the breakdown phenomenon in the GIS and the values of Toepler´s constant (kt), which gives an estimation of the formative time lags, were determined. Results show that the formative time lags vary inversely with gas pressure and the gas mixture concentrations for two gaps studied (0.46 mm and 0.61 mm). In the case of another gap (0.20 mm), the variation in the formative time lags with pressure as well as SE, concentration in the mixture has been found to be negligibly small between gas mixtures, although significant variation can be seen between pure SF6 and pure N2. Toepler´s constant, kt, increases with gas pressure as well as SF6 concentration in the mixture for the gaps studied. Hence, kt is a function of the gas pressure and the concentrations of SF6 in the gas mixture for the above-mentioned gaps.
Keywords :
SF6 insulation; electric breakdown; gas insulated switchgear; gas mixtures; insulation testing; nitrogen compounds; sparks; switchgear testing; 0.20 mm; 0.46 mm; 0.61 mm; 145 kV; 50 Hz; SF6-N2; Toepler´s constant; Toepler´s spark law; breakdown phenomenon; compressed SF6-N2 gas insulated system; fast response capacitive sensor; formative time lags; gas gaps; very fast transient over voltage; Breakdown voltage; Circuit breakers; Computational modeling; Computer simulation; Electric breakdown; Gas insulation; Geographic Information Systems; Sparks; Time measurement; Voltage control;
fLanguage :
English
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
Publisher :
ieee
ISSN :
1070-9878
Type :
jour
DOI :
10.1109/TDEI.2003.1207478
Filename :
1207478
Link To Document :
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