Dielectric breakdown properties of SF{sub 6}-N{sub 2} mixtures at 0.01-1.6 MPa and 300-3000 K
- State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 XianNing West Road, Xi'an, Shaanxi Province 710049 (China)
- CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield NSW 2070 (Australia)
The dielectric breakdown properties of SF{sub 6}-N{sub 2} mixtures were investigated at different concentrations of N{sub 2}, 0.01-1.6 MPa, and 300-3000 K. The equilibrium compositions of different SF{sub 6}-N{sub 2} mixtures at several gas pressures and temperatures up to 3000 K were first calculated by minimizing the Gibbs free energy under the assumptions of local thermodynamic and chemical equilibrium. The electron energy distribution function was then obtained using the composition data by Boltzmann equation analysis. It was found that adding N{sub 2} to SF{sub 6} gas can markedly reduce the kinetic energy of electrons at relatively high gas temperatures, which enhances the dielectric field strength. Finally, the critical reduced electric field (E/N){sub cr}, defined as the value for which ionization is equal to attachment, of hot SF{sub 6}-N{sub 2} mixtures was determined. The results indicate that in the gas temperature range around 2000-3000 K, increasing the concentration of N{sub 2} effectively enhances the (E/N){sub cr} of SF{sub 6}-N{sub 2} mixtures, and the (E/N){sub cr} of SF{sub 6}-N{sub 2} mixtures at a wide range of concentrations of N{sub 2} (5%, 50%, and 95%) are all higher than that of pure SF{sub 6} gas. Further, this trend exists at all the gas pressures considered (0.01-1.6 MPa).
- OSTI ID:
- 22102340
- Journal Information:
- Journal of Applied Physics, Vol. 113, Issue 14; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
36 MATERIALS SCIENCE
BOLTZMANN EQUATION
BREAKDOWN
COLLISIONS
DIELECTRIC MATERIALS
DIELECTRIC PROPERTIES
ELECTRIC FIELDS
ELECTRON TEMPERATURE
ENERGY SPECTRA
FREE ENERGY
ION TEMPERATURE
IONIZATION
KINETIC ENERGY
NITROGEN COMPOUNDS
PLASMA PRESSURE
SULFUR FLUORIDES