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Title: Study of the dielectric breakdown properties of hot SF{sub 6}–CF{sub 4} mixtures at 0.01–1.6 MPa

The dielectric breakdown properties of SF{sub 6}–CF{sub 4} mixtures were investigated at different ratios of SF{sub 6}, 0.01–1.6 MPa, and gas temperatures up to 3000 K. Initially, the equilibrium compositions of SF{sub 6}–CF{sub 4} mixtures were calculated by minimizing the Gibbs free energy under the assumptions of local thermodynamic and chemical equilibrium. Then the electron energy distribution function was obtained based on those data by solving the Boltzmann equation under the zero-dimensional two-term spherical harmonic approximation. Finally, the critical reduced electric field strength (E/N){sub cr} of SF{sub 6}–CF{sub 4} mixtures, which is defined as the value for which total ionization reaction is equal to total attachment reaction, were determined and analyzed. The results confirm the superior breakdown properties of pure SF{sub 6} at relatively low gas temperatures. However, for higher gas temperatures (i.e., T > 2200 K at 0.4 MPa), the (E/N){sub cr} in SF{sub 6}–CF{sub 4} mixtures are obviously higher than that in pure SF{sub 6} and the values of (E/N){sub cr} increase with the reduction of the ratio of SF{sub 6}.
Authors:
; ;  [1] ;  [2]
  1. State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, No. 28 XianNing West Road, Xi’an, Shaanxi Province 710049 (China)
  2. CSIRO Materials Science and Engineering, PO Box 218, Lindfield, NSW 2070 (Australia)
Publication Date:
OSTI Identifier:
22218244
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 5; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BOLTZMANN EQUATION; BREAKDOWN; DIELECTRIC MATERIALS; ELECTRIC FIELDS; ELECTRONS; ENERGY SPECTRA; FREE ENERGY; FREE ENTHALPY; MIXTURES; ORGANIC COMPOUNDS; PRESSURE RANGE MEGA PA; SULFUR FLUORIDES