Impact mechanism and regularity of trace H2O on SF6 decomposition characteristic under PD

H
₂
O is one of the most important factors that affect the final SF
₆
decomposition products, the products concentration, and the production rate, and so on, under partial discharge (PD). However, the mechanism and regular pattern of SF
₆
decomposition haven't been figured out completely. This paper had made several experiments, as long as 48h, research SF
₆
PD decomposition in different H
₂
O contents, all experiments utilize the test platform of SF
₆
PD decomposition, and then detect the concentration of SF
₆
decomposition products in different H
₂
O contents. It had obtained the regular pattern of the effects of H
₂
O on SF
₆
PD decomposition. The results indicate: increasing H
₂
O contents can restrain the generation of CF
₄
, and the generation of CO
₂
is more than CF
₄
. Moreover, H
₂
O will firstly promote the generation of both SO
₂
F
₂
and SOF
₂
, and then inhibit them as time goes on. Discriminatively, the promotion and inhibition leaded by H
₂
O of SOF
₂
are stronger than that of SO
₂
F
₂
. Therefore, when diagnoses facilities faults through using the SF
₆
decomposition products, the effect of H
₂
O should be taken into account.