From the microscopic and energy perspectives

there are few studies on discharge decomposition of SF

6

under the action of micro-water and micro-oxygen.Based on the density functional theory

this paper simulates the decomposition process of SF

6

discharge containing micro-water and micro-oxygen at normal temperature and pressure from a microscopic point of view.Firstly

the SF

6

molecule and its main discharge decomposition products a

re modeled

and the reaction of SF

6

molecular discharge into low sulfur fluoride is simulated and calculated

and the energy changes before and after the reaction are obtained.Secondly

analysis of the reaction of low-fluorine sulfide with micro-water and micro-oxygen.Finally

the ionization parameters of the main products of SF

6

discharge decomposition are calculated

and the difference between the related ionization parameters of the product and the SF

6

gas is compared.Studies have shown that the low sulfur fluorides SF

3

·

SF

4

·

SF

5

· decomposed by SF

6

under normal temperature and pressure react with micro-water and micro-oxygen

which is the main way of SF

6

discharge decomposition.The ionization energy of SF

6

discharge decomposition products is more than 11 eV.It is larger than the energy of most electrons in low-temperature plasma

and has good electric strength.However

most of its molecular structure is less stable and less resistant than SF

6

.Therefore

the overall insulation performance after SF

6

decomposition is weaker than before decomposition in GIS/GIL.