High voltage research (breakdown strengths of gaseous and liquid insulators). Semiannual report, April 1--September 30, 1977

Technical Report · Tue Nov 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/5413599· OSTI ID:5413599

Christophorou, L. G.; James, D. R.; Pai, R. Y.; Mathis, R. A.; Pace, M. O.; Bouldin, D. W.; Christodoulides, A. A.; Chan, C. C.

Direct current breakdown strength measurements on a large number of multicomponent gas mixtures at low (approximately less than 1 atm) and high (approximately less than 5 atm) pressures led to the discovery of many gas mixtures of electron-attaching gases and strongly electron-attaching gases with N/sub 2/ and C/sub 3/F/sub 8/ which are superior to SF/sub 6/. Of special significance are mixtures containing C/sub 4/F/sub 6/ (perfluoro-2-butyne). The breakdown strength of one such mixture (20 percent C/sub 4/F/sub 6/ to 80 percent SF/sub 6/) is approximately 30 percent higher than pure SF/sub 6/ under identical conditions, both at low (approximately 0.7 atm) and high (4.6 atm) pressures. Perfluorocyclohexene (C/sub 6/F/sub 10/) and C/sub 5/F/sub 8/ (perfluorocyclopentene) were found at low pressure (approximately 0.2 atm) to be, respectively, approximately 2.1 and 2.2 times better than SF/sub 6/ under comparable conditions; they both have a potential as additives in gas mixtures. The effect of the inelastic electron scattering properties of a gas via negative ion resonances in the low-energy range (1 to approximately 4 eV) on the breakdown strength has been demonstrated for H/sub 2/, N/sub 2/, and CO and binary mixtures of these with SF/sub 6/ and C/sub 4/F/sub 6/ (perfluoro-2-butyne). The construction of a new high pressure (to approximately 11 atm), variable temperature (-50/sup 0/C to + 150/sup 0/C) apparatus has been completed and a practical test facility utilizing cylindrical electrode geometries has been put into operation; the first results on the latter apparatus were on SF/sub 6/-N/sub 2/ and c-C/sub 4/F/sub 8/--N/sub 2/ mixtures. Studies of environmental effects of dielectric gases via their electron-impact-induced decompositions and analysis of their breakdown products have begun using mass spectrometry and gas chromatography; C/sub 4/F/sub 6/ (perfluoro-2-butyne) seems to be resistant to electron-impact-induced decomposition indicating long-term stability.

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5413599
• Report Number(s): ORNL/TM-6113
• Country of Publication: United States
• Language: English

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200300* -- Electric Power Engineering-- Power Transmission & Distribution-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
BREAKDOWN
CABLES
CARBON COMPOUNDS
CARBON FLUORIDES
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CONDUCTOR DEVICES
CRYOGENIC FLUIDS
DIELECTRIC PROPERTIES
DISPERSIONS
ELECTRIC CABLES
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELEMENTS
EQUIPMENT
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
GAS-INSULATED CABLES
HALIDES
HALOGEN COMPOUNDS
HYDROGEN
MIXTURES
NITROGEN
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWER SYSTEMS
RESEARCH PROGRAMS
SULFUR COMPOUNDS
SULFUR FLUORIDES