Dielectric strength of alternative insulation gases at high pressure

Sulphur hexafluoride (SF6) is the most common insulation gas in high voltage technology. Besides the excellent insulation properties SF6 has the most known global warming potential. Alternative insulation gases have only a fraction of the insulation level of SF6. The electric strength of gases depends on the gas density and can be increased significantly by using higher pressure. Therefore the investigation of alternative insulation gases especially breakdown measurements were executed up to pressures of 2.6 MPa. The aspirants were air, O2, N2, O2-N2-mixtures, CO2 in comparison to SF6 and SF6-N2-mixtures. With these measurements the electrical breakdown strength of alternative insulation gases in quasi-homogeneous and also the slightly inhomogeneous electric fields and the applicability of…