Non-uniform field breakdown characteristics of SF6/CF4 mixtures at various pressures

The breakdown and the corona inception voltages experiments of SF₆/CF₄ mixtures in non-uniform field were performed. The experiments were carried out under AC, positive and negative standard lightning impulse (SLI) voltages. The point-plane electrode was used to make non-uniform field and gap distance was 3 mm. SF₆/CF₄ mixtures pressure ranged from 0.1 to 0.5 MPa and the percentage of SF₆ and CF₄ was 0, 20, 40, 60, 80 and 100%. Under positive SLI the breakdown voltage was increased slowly as pressure increasing but under negative SLI the breakdown voltage was increased slightly as pressure increasing. At low pressure the breakdown voltage of positive and negative SLI was similar. Under AC voltage the breakdown voltage was increased linearly but the corona inception voltage was saturated over 0.2 MPa. This paper suggests elementary data in gas insulated systems.