Competing mechanisms of charge-induced electric field distortion and charge-involved neutralization on surface discharge

Charge-induced surface discharge poses a critical risk to the operational reliability of high-voltage direct current gas-insulated equipment and pulsed power system. In this study, we investigate the effects of charge-induced electric field distortion and charge involvement during surface discharge by separately depositing charge spots on two dielectric layers. The results show that deposited positive charges inhibit positive streamer development, whereas negative charges facilitate it, primarily due to electric field distortion induced by deposited charges. Nevertheless, the involvement of deposited charges in streamer development predominantly exhibits a neutralizing effect, exerting an opposite influence on the streamers. This highlights a competitive relationship between deposited charge involvement and electric field distortion. Additionally, the neutralization of deposited charges with electron avalanches reduces the impact of charge-induced electric field distortion, thereby mitigating its effects on discharge.