Corona Discharge Mechanism and Breakdown Voltage Characteristics from Metallic Floating Particle in SF6 Gas under dc Voltage

Corona discharge mechanism based on corona current pulse characteristics from a metallic floating particle was investigated in SF ₆ gas under DC voltage as a basis for clearly understanding of corona discharge mechanism in SF₆ gas gap with floating particle under AC voltage. Corona behavior and breakdown voltage were investigated by changing the particle position in the gap. It shows that active development of corona and local minimum in breakdown voltage characteristic were observed when the particle is in the vicinity of the electrode due to local arc bridges intermittently the minor gap between the particle and electrode. However, it is obscure as compared with the one in air gap, where the breakdown fell to corona onset voltage