Numerical investigation of synergistic effect of insulation gas mixtures

Due to the greenhouse effect of SF
₆
gas, searching for new environmentally friendly substitutes gases has become an urgent task for the electrical industry. In this paper, we have employed a two-dimensional fluid model to analyze the synergistic effect of insulation gas mixtures. The results show that the addition of N2 will significantly change the insulation ability of CF3I while has relatively little effect on SF
₆
. The critical breakdown field decreases more quickly in CF3I/N2 mixture with higher N2 content. The velocity and peak electron density of the discharge also has a greater change as the N
₂
content varies from 0% to 90% in CF3I/N2 mixture. The influences of two buffer gases are also compared. The results show that N2 has a better performance than CO
₂
as the buffer gas for SF
₆
or CF3I.