Space charge behaviour and corona stabilization effect in SF6 gas viewed from sequential generation of a dc partial discharge

We investigated the sequential generation characteristics of partial discha rge (PD) pulses in SF6 gas under the application of a positive dc voltage, in order to discuss the PD mechanism based on space charge behaviour and co rona stabilization effect. Highly time-resolved measurement of PD current p ulses enabled us to discuss the relationship between the PD charge q and th e time interval Deltat of sequential PD pulses. Experimental results reveal ed that q-Deltat characteristics exhibited negative and positive correlatio n at small and large Deltat regions, respectively. Numerical calculations o f ion diffusion and ion drift verified the time-dependent characteristics o f the space charge behaviour and the resultant corona stabilization effect.