Continuous Monitoring of SF{sub}6 Degradation in High Voltage Switchgear using Raman Scattering

摘要

In high voltage SF{sub}6 insulated switchgear, the level of SF{sub}6 concentration needs to he monitored regularly because of its degradation by switching arcs and on-going partial discharges or coronas. In the work reported here, measurements of SF{sub}6 dissociation rate following 75 μA positive and negative coronas have been made using a mass spectrometer and Raman spectroscopy. The two sets of data correlate well, the rates of degradation of SF{sub}6 and production of gaseous by-products being shown to be proportional to the charge transported by the corona. SF{sub}6 provides a particularly strong Raman signal at 773.5 cm{sup}(-1), and the results demonstrate the feasibility of using Raman scattering to monitor SF{sub}6 degradation in high-voltage switchgear.