The correction of humidity in dielectric strength lightning impulse testing - comments

2001 ◽  
Author(s):  
L.G. Tortelli Faraco
Keyword(s):  
Dielectric Strength ◽  
Lightning Impulse

scholarly journals Green Gas for Grid as an Eco-Friendly Alternative Insulation Gas to SF6: A Review

2020 ◽  
Vol 10 (7) ◽  
pp. 2526 ◽  
Author(s):  
Baofeng Pan ◽  
Guoming Wang ◽  
Huimin Shi ◽  
Jiahua Shen ◽  
Hong-Keun Ji ◽  
...  
Keyword(s):  
Sulfur Hexafluoride ◽  
Heat Dissipation ◽  
Circuit Breaker ◽  
Chemical Properties ◽  
Electric Power Industry ◽  
Dielectric Strength ◽  
Environmental Concerns ◽  
Current Test ◽  
Lightning Impulse ◽  
Liquefaction Temperature

This paper deals with a review of the state-of-the-art performance investigations of green gas for grid (g3) gas, which is an emerging eco-friendly alternative insulation gas for sulfur hexafluoride (SF6) that will be used in gas-insulated power facilities for reducing environmental concerns. The required physical and chemical properties of insulation gas for high-voltage applications are discussed, including dielectric strength, arc-quenching capability, heat dissipation, boiling point, vapor pressure, compatibility, and environmental and safety requirements. Current studies and results on AC, DC, and lightning impulse breakdown voltage, as well as the partial discharge of g3 gas, are provided, which indicate an equivalent dielectric strength of g3 gas with SF6 after a proper design change or an increase in gas pressure. The switching bus-transfer current test, temperature rise test, and liquefaction temperature calculation also verify the possibility of replacing SF6 with g3 gas. In addition, the use of g3 gas significantly reduces theabovementioned environmental concerns in terms of global warming potential and atmosphere lifetime. In recent years, g3 gas-insulated power facilities, including switchgear, transmission line, circuit breaker, and transformer, have been commercially available in the electric power industry.

Experimental study on the lightning impulse dielectric strength of liquid nitrogen insulation medium according to various pressures

2011 ◽  
Vol 471 (21-22) ◽  
pp. 1581-1585 ◽  
Author(s):  
J.B. Na ◽  
H. Kang ◽  
K.S. Chang ◽  
Y.J. Kim ◽  
S.Y. Chu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Liquid Nitrogen ◽  
Dielectric Strength ◽  
Lightning Impulse

Dielectric strength of oil-immersed transformer insulation with superimposed AC and lightning impulse voltage

1990 ◽  
Vol 25 (4) ◽  
pp. 683-687 ◽  
Author(s):  
Y. Kamata ◽  
K. Endoh ◽  
S. Furukawa ◽  
F. Endoh ◽  
K. Nonomura ◽  
...  
Keyword(s):  
Dielectric Strength ◽  
Impulse Voltage ◽  
Lightning Impulse ◽  
Transformer Insulation

scholarly journals Lightning Impulse Withstand of Natural Ester Liquid

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1964 ◽  
Author(s):  
Stephanie Haegele ◽  
Farzaneh Vahidi ◽  
Stefan Tenbohlen ◽  
Kevin Rapp ◽  
Alan Sbravati
Keyword(s):  
Breakdown Voltage ◽  
Dielectric Strength ◽  
Mineral Oil ◽  
Homogeneous Field ◽  
Inhomogeneous Field ◽  
Insulating Liquids ◽  
Lightning Impulse ◽  
Insulating Liquid ◽  
Natural Ester ◽  
Inhomogeneity Factor

Due to the low biodegradability of mineral oil, intense research is conducted to define alternative liquids with comparable dielectric properties. Natural ester liquids are an alternative in focus; they are used increasingly as insulating liquid in distribution and power transformers. The main advantages of natural ester liquids compared to mineral oil are their good biodegradability and mainly high flash and fire points providing better fire safety. The dielectric strength of natural ester liquids is comparable to conventional mineral oil for homogeneous field arrangements. However, many studies showed a reduced dielectric strength for highly inhomogeneous field arrangements. This study investigates at which degree of inhomogeneity differences in breakdown voltage between the two insulating liquids occur. Investigations use lightning impulses with different electrode arrangements representing different field inhomogeneity factors and different gap distances. To ensure comparisons with existing transformer geometries, investigations are application-oriented using a transformer conductor model, which is compared to other studies. Results show significant differences in breakdown voltage from an inhomogeneity factor of 0.1 (highly inhomogeneous field) depending on the gap distance. Larger electrode gaps provide a larger inhomogeneity at which differences in breakdown voltages occur.

Rigidité diélectrique d'un interface gaz–support avec contaminant métallique dans l'air sec et ses mélanges avec le SF6

2006 ◽  
Vol 84 (5) ◽  
pp. 381-398
Author(s):  
Adolphe Moukengué Imano
Keyword(s):  
Dielectric Strength ◽  
Partial Discharges ◽  
Dry Air ◽  
Voltage Stress ◽  
Flashover Voltage ◽  
Lightning Impulse ◽  
Conducting Particle ◽  
Series Of Experiments ◽  
Inception Voltage ◽  
Floating Electrode

In this paper, we conduct a series of experiments aimed at analysing the dielectric properties of compressed dry air, and some SF6–air mixtures up to 700 kPa, under application of AC 50 Hz and lightning impulse (LI) 1.2 μs/50 μs voltage. The investigations were carried out by using a cylindrical spacer model with an adhering particle on the surface under homogenous field conditions. We measure the partial discharges (PD) propagation characteristics under LI voltage stress, as well as the PD inception voltage and the flashover voltage for the contaminated particle. We also investigate the surface charge accumulation on the spacer surface under contaminated particle conditions. The results of the experiments reveal the influence a conducting particle has on the determined flashover field strength, for SF6–air mixtures compared with pure, compressed dry air. This influence is discussed for different particle lengths, but also for three different particle positions in the gap. Pure dry air achieves a higher dielectric strength when the particle gets into contact with the high voltage electrode, under negative LI voltage stress. The same result is obtained for the SF6–air mixtures, when the particle is located in the middle of the gap, as floating electrode on the spacer surface. The reported results contribute to the improvement of the models of breakdown through the interface gas–solid isolator. The application of these models should offer the possibility for considering the use of dry air, or its mixtures with SF6 which, normally have a lower relative global warming potential than pure SF6.[Traduit par la Rédaction]

Characteristics of Negative Lightning Impulse Breakdown Voltage in Pure Water

2018 ◽  
Vol 138 (8) ◽  
pp. 441-448 ◽  
Author(s):  
Norimitsu Takamura ◽  
Nobutaka Araoka ◽  
Seiya Kamohara ◽  
Yuta Hino ◽  
Takuya Beppu ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Pure Water ◽  
Lightning Impulse

Influence of the Test Voltage Function over Lightning Impulse Response Parameters Measured by Long Cable

2018 ◽  
Vol 138 (3) ◽  
pp. 242-248 ◽  
Author(s):  
Shuji Sato ◽  
Seisuke Nishimura ◽  
Hiroyuki Shimizu ◽  
Hisatoshi Ikeda
Keyword(s):  
Impulse Response ◽  
Lightning Impulse ◽  
Test Voltage
Sign in / Sign up

Export Citation Format

Share Document