This paper analyses the insulation characteristics of c-C4F8/N2 gas mixtures using the improved Monte Carlo method with the null-collision technique and studies the possibility of applying that in the gas insulation of power equipment. The density-normalized effective ionization coefficient for c-C4F8/N2 gas mixtures has been calculated using a sample of a pulsed Townsend discharge. The overall density-reduced electric field strengthcould be varied between 160 and 480 Td (1Td = 10−21 V m2), while the c-C4F8 content in the gas mixtures is varied over the range 0–100%. From the variation curve of with the c-C4F8 mixture ratio , the limiting field of the gas mixture at different gas contents is determined. The required gas pressure ratios comparable to the insulation property of SF6 and the global warming potential (GWP) at this gas pressure were also investigated. It is found that the dielectric strength of c-C4F8/N2 mixtures is less than that of the SF6/N2 gas mixture at below 60%, and is larger at above 60%, and the GWP of the former is significantly lower than that of the latter.
