Space charge behavior in SF6 gas and sequential generation of PD pulses

We observed time-resolved partial discharge (PD) characteristics under ac and dc conditions in order to demonstrate the effects of space charge behavior and the corona stabilization effect in SF₆ gas. From the experimental results, we found that the charge magnitude of the first PD in the positive half cycle of applied ac voltage depended only on the instantaneous voltage. Under dc conditions we found that the magnitude of the PD charge related closely to the time interval between PD pulses. Space charge behavior and the PD generation mechanism are interpreted diagrammatically, and we describe how positive ions reduce the magnitude of PD charge and activate the corona stabilization effect and that the negative ions shorten the time interval between PD pulses