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

As a traditional insulating gas, SF6 has a serious greenhouse effect. At present, SF6/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 SF6/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 SF6/N-2 gas mixture are studied under the experimental conditions of 25 degrees C and 0.3MPa pressure. The development process of corona discharge in SF6/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 SF6/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.