Calculation of dielectric strength of the SF/sub 6//N/sub 2/ gas mixture in macroscopically and microscopically non-uniform fields

Dielectric strength of the SF/sub 6//N/sub 2/ gas mixture in a uniform field can be calculated using a simple method assuming there is no interaction between the different component gas molecules. However, to calculate the dielectric strength of the gas mixture in a practical gas-insulated system, both the electrode curvature factor and the electrode surface roughness factor should be taken into account. This paper presents the electrode curvature factors for SF/sub 6//N/sub 2/ in a coaxial electrode system and in a concentric spherical electrode system, and reports the effect of electrode surface roughness on breakdown in the SF/sub 6//N/sub 2/ gas mixture.<>