Experimental Study on Corona Discharge Characteristics of SF6/N2 Gas Mixture in Needle-plane Model

As a traditional insulating gas, SF
6
has a serious greenhouse effect. At present, SF
6
/N
2
gas mixture, as an alternative to environmental protection, has good application prospects and attracts wide attention of scholars. In order to investigate the corona discharge characteristics of SF
6
/N
2
gas mixture under DC voltage, an experimental platform for needle-plane model corona discharge is built in this paper. The effects of N
2
content on discharge characteristics of SF
6
/N
2
gas mixture are studied under the experimental conditions of 25℃ and 0.3MPa pressure. The development process of corona discharge in SF
6
/N
2
gas mixture is analyzed, and the variation of initial voltage and the main pulse characteristic parameters of gas mixture with different N
2
content under negative DC voltage are measured. The results show that the corona discharge process in SF
6
/N
2
gas mixture can be divided into four stages. With the increase of N
2
content, the initial voltage will decrease and the pulse repetition rate will increase. The rise time will not change with N
2
content, the fall time and the pulse duration have no obvious regularity, and the pulse amplitude shows different trends under different N
2
content.