Considering that the accident potential of insulation breakdown and burnout of transformer coil exists

since the corrosive sulfur in insulating oil

which would react with copper wire during transformer operation

and produce Cu2S;as a result of Cu2S′s conductive characteristic

the insulated paper of wire were penetrated and polluted

comprehensive investigation of 500 kV transformers in Guangdong power grid corporation was carried out and the investigation result shows that corrosive sulfur existed in 29 of 201 transformers

as a proportion of 14.4%.Furthermore

deactivator was added to transformers containing corrosive sulfur and the tracking data of these transformers indicated the feasibility and validity of preventing transformer fault related to corrosive sulfur through adding deactivator.