Increasing demand for an alternative insulation medium to sulphur hexafluoride (SF6) has led to the investigation of new environmentally friendly insulation gases which could be used in high voltage equipment on the electrical power network. One such alternative, which is currently being explored by researchers, is Trifluoroiodomethane (CF3I) which could potentially be used in a gas mixture with carbon dioxide (CO2) as an insulation medium. In this paper an analysis of gaseous by-products detected as a result of high voltage breakdown through pure CF3I and a CF3I-CO2 gas mixture across a sphere-sphere electrode arrangement is given. Gas chromatography and mass spectrometry (GCMS) is used to identify the gaseous by-products produced as a result of high voltage arcing which causes the gas between the electrodes to dissociate. Analysing these gas by-products helps to identify the long-term behaviour of the gas mixture in high voltage equipment.
Keywords: Gas Insulated Lines (GIL); Gas Insulated Switchgear (GIS); High Voltage Gas Insulation; Sulphur Hexafluoride (SF6); Trifluoroiodomethane (CF3I).