Dielectric properties of fluorine containing insulating gases for gas insulated systems

Summary

For decades, sulfur hexafluoride (SF6) has been the established insulating gas for medium and high voltage installations. SF6 is one of four listed greenhouse gases in the Kyoto Protocol (1997), of which emissions need to be reduced. This paper reports about the dielectric properties of alternative fluoro-organic insulating gases with low global warming potential. The scope of the paper is on the dielectric properties of gas-insulated systems like gas-insulated lines. These system designs do not require a switching functionality. The dielectric breakdown studies are performed using different sizes of test vessels and electrode arrangements to determine scaling factors. Different sets of electrodes, different types of electrode material and surface roughness are applied in the tests to investigate the influence of these parameters. The tests are performed with AC voltage and lightning impulse voltage of positive and negative polarity for a variation of gas mixtures with different ratio. Therefore, it is necessary to ensure that the homogeneous blending of the different gases is given under all circumstances, before the tests as well as after breakdowns. Interactions of different gas types in consecutive test series have to be avoided.

Additional informations

Authors

GACEK, GONOS, Batista Suelson

Keywords

gas insulation, alternative gases, sf6