Use of hydroxyl-modified carbon nanotubes for detecting SF6 decomposition products under partial discharge in gas insulated switchgear

Gas-insulated switchgear (GIS) has inherent internal defects that may result in partial discharge (PD) and the eventual development of equipment faults. PD in GIS can lead to the generation of multiple decomposition products of SF₆, and the detection and analysis of these decomposition products is important for fault diagnosis. In this paper, a molecular dynamics simulation software package, Materials Studio (MS), is used to model accurately the processes by which single-walled carbon nanotubes modified by hydroxyl (SWNT-OH) adsorb the main decomposition products of SF₆ (SOF₂, SO₂F₂, SO₂ and CF₄) generated by PD. In addition, experimental studies are performed to validate the predicted gas-sensing characteristics. The theoretical calculations and experimental results both indicate that, of the four gases, SWNT-OH showed the fastest response time and highest sensitivity to SO₂. The sensitivities of SWNT-OH to the other gases were low, and response times long. We conclude that SWNT-OH shows good sensitivity and selectivity to SO₂.