Correlation Characteristics Between Partial Discharge Quantity and SF6 Decomposition Component Under Negative DC

Aimed to clarify the correlation characteristics between the SF₆ decomposition components under negative DC partial discharge (PD) initiated by free metal particles defect and discharge intensity, SF₆ decomposition data was obtained under different voltages on the basis of constructing SF₆ decomposition experimental platform. The variation law of the SF₆ decomposition components and the characteristic ratios were systematically studied. The results show that SF₆ decomposes into CO₂, SO₂F₂, SOF₂, SO₂ under the action of PD. The yield relationship of different decomposition components exists big difference at different discharge intensity. The change trends of the concentration of three sulfur compounds SOF₂, SO₂F₂ and SO₂ with Q_sec are basically the same and can be approximately divided into two periods: rapid growth period and slow growth period in negative DC. The change curves of carbon compound CO₂ with PD strength present three stages: growth, saturation, and then growth.