DocumentCode :
47483
Title :
Evaluation of breakdown characteristics of CO2 gas for non-standard lightning impulse waveforms - breakdown characteristics in the presence of bias voltages under non-uniform electric field
Author :
Wada, Junichi ; Ueta, Genyo ; Okabe, Shigemitsu
Author_Institution :
Tokyo Electr. Power Co., Yokohama, Japan
Volume :
20
Issue :
1
fYear :
2013
fDate :
Feb-13
Firstpage :
112
Lastpage :
121
Abstract :
SF6 gas, an insulation medium used for gas insulated switchgear (GIS), has a high global warming potential, hence the search for an effective alternative is required from an environmental perspective. The authors focus particularly on CO2 gas, which has a low global warming potential, as one of these potential alternatives. In order to apply this CO2 gas to actual equipment, the insulation characteristics for overvoltage waveforms generated in an actual field (called non-standard lightning impulse waveforms) must be obtained. The present study obtained and evaluated the insulation characteristics where a disconnector switching surge was superimposed over the residual dc component (bias voltage) caused by operating a switchgear under a non-uniform electric field, typically represented by metallic particles. Consequently, it was concluded that the breakdown voltage was lower for positive polarity under a non-uniform electric field in the presence of a bias voltage and that it was appropriate to conduct an experiment using a positive polarity waveform in the study of dielectric strength. Furthermore, it emerged that the breakdown voltage for a positive polarity waveform was 1.05 to 1.64 times higher than that for the standard lightning impulse waveform, even if the frequency and damping rate were changed.
Keywords :
SF6 insulation; carbon compounds; electric breakdown; electric fields; electric strength; gas insulated switchgear; global warming; lightning; CO2; GIS; SF6; bias voltages; damping rate; dielectric strength; disconnector switching surge; gas breakdown characteristic evaluation; gas insulated switchgear; high global warming potential; metallic particles; nonstandard lightning impulse waveforms; nonuniform electric field; overvoltage waveform insulation characteristics; positive polarity waveform; residual dc component; Breakdown voltage; Damping; Electric fields; Gas insulation; Lightning; Oscillators; CO2 gas gap; Gas insulated switchgear (GIS); dielectric breakdown voltage ?? time characteristics (V-t characteristics); non-standard lightning impulse waveform; nonuniformelectric field;
fLanguage :
English
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
Publisher :
ieee
ISSN :
1070-9878
Type :
jour
DOI :
10.1109/TDEI.2013.6451348
Filename :
6451348
Link To Document :
بازگشت