Influence of H2O and O2 on the main discharge mechanism in 50 Hz ac point-plane corona discharge

It is common to identify the internal insulation conditions of Sulfur Hexafluoride (SF6) insulated equipment by monitoring the concentrations of SF6 decomposition products. Corona discharge can lead to the decomposition of SF6, and thus, a lot of reactions occur in the mixture of SF6 with the impurities H2O and O-2 Even under the same strength of corona discharge, the reactions can cause the decomposition products to differ due to the different concentrations of H2O and O-2. This paper systematically studies the effects of H2O and O-2 on the formation mechanism of SF6 decomposition products from a theoretical perspective. Two coupled zero-dimensional chemical kinetic models were built to investigate the discharge mechanism of 50 Hz ac point-plane corona discharge. By calculating the related contributions of the pathways at different moisture and oxygen contents (from 200 ppm to 5000 ppm), the main chemical process and the influence of the moisture and oxygen contents on the main discharge mechanism are analyzed. Published raider license by AIP Publishing.