Journal ArticleDOI
Factors Controlling Surface Flashover in SF6 Gas Insulated Systems
TLDR
In this article, various factors controlling flashover of solid insulators in pressurized SF6, are reviewed and their influences in gas insulated systems are discussed from a practical point of view.Abstract:
Various factors controlling the flashover of solid insulators in pressurized SF6, are reviewed and their influences in gas insulated systems are discussed from a practical point of view. Flashover voltage of clean insulator surface is under the influence of the insulator-metal contact as well as the macroscopic electric field distortion due to the high dielectric permittivity of solid insulator. Conducting particles or even fine metal powder can reduce the flashover voltage. Their effects are strongly dependent on the position they are located, the size of the insulator and gas pressure. Humidity of SF, gas should be strictly governed in SF, gas insulated apparatuses, since the condensation of water can decrease flashover voltage considerably. Decomposition products of SF6 due to the arcing in switchgears are deleterious to epoxy insulators particularly when silica is used as their filler. The decomposition products decrease the leakage resistance on the insulation surface. The field strength near positive electrode is enhanced by the electrolytic effect in the surface conduction layer. In some extreme condition, it initiates tracking on the insulator surface.read more
Citations
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Journal ArticleDOI
SF6 Decomposition in Gas-Insulated Equipment
TL;DR: In this article, the authors present a review of previous research in SF6 decomposition relating to the operation of gas-insulated switchgears, gas-instrained transmission lines, and electrostatic accelerators.
Journal ArticleDOI
Mechanisms of Surface Flashover Along Solid Dielectrics in Compressed Gases: a Review
TL;DR: A review of surface flashover with primary emphasis on the understanding of physical processes leading to discharge initiation and insulator flashover under high voltage excitation is presented in this article, where the authors suggest a physical explanation for the observed phenomena, including ionization, surface charging, partial discharges, optical activity and gas/dielectric interactions.
Journal ArticleDOI
Gas-Insulated Cables
TL;DR: In this paper, the design philosophy and development for the "rigid", flexible, and semi-flexible isolated phase lines, the three-conductor lines and the prototype dc gas-insulated cable system are reviewed.
Journal ArticleDOI
SF6-alternative gases for application in gas-insulated switchgear
Journal ArticleDOI
Dielectric strength coordination and generalized spacer design rules for HVAC/DC SF/sub 6/ gas insulated systems
TL;DR: In this paper, the problems of HVAC/DC gas insulated systems (GIS) dielectric strength coordination and support spacers design criteria are discussed in order to protect the spacers against flashover and consequently exclude them from consideration when coordinating an insulation of GIS.
References
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Journal ArticleDOI
Criteria for Spark Breakdown in Sulfur Hexafluoride
TL;DR: In this paper, the mechanisms of spark breakdown in SF6 and other electronegative gases are discussed, and quantitative criteria are derived for the Townsend type and the streamer type of breakdown in nonuniform fields.
Journal ArticleDOI
Electrical Breakdown of Long Gaps in Sulfur Hexafluoride
T. Nitta,Y. Shibuya +1 more
TL;DR: In this article, the electrical discharge characteristics of SF6 are discussed theoretically in relation to the field dependence of the ionization coefficient a and the electron attachment coefficient, and a simple theoretical formulation of breakdown or corona inception voltages of gaps in SF6 is derived.
Journal ArticleDOI
Free Conducting Particles in a Coaxial Compressed-Gas-Insulated System
Armin Diessner,John G. Trump +1 more
TL;DR: In this paper, the effect of free conducting particles (FCP) on voltage-insulating performance of a short length of transmission line was quantitatively studied over the pressure range 0 to 300 psig for nitrogen and 0 to 125 PSig for SF6.
Journal ArticleDOI
Electrical Decomposition of Sulfur Hexafluoride
Journal ArticleDOI
Effect of Solid Impurities on Breakdown in Compressed SF6 Gas
TL;DR: In this paper, the effects of conducting particles and insulating fibers are described under alternating, impulse and alternating-impulse superposed voltage conditions for a 500kV gas insulated substation already put into service in Japan.