Dynamic Interface Charge Behaviors in HVDC Cable Terminal Considering Carrier Dynamic Equilibrium

抄録

The cable terminal composed of rubber and epoxy resin is a critical component connecting high voltage direct current (HVDC) cable and gas insulated substations (GIS). The interface is the most vulnerable part of cable terminal insulation because of the interface charge accumulation issues under DC voltage, which causes electric field distortion and even interface discharge or breakdown. In this paper, an interface charge behavior simulation model considering carrier dynamic equilibrium is established, and the interface charge characteristics during polarization and depolarization process under single polarity voltage and polarity reversal voltage are analyzed. The results indicate that the charges mainly accumulate at the solid-gas interface after polarization, which leads to a serious electric field concentration in SF₆. The charge accumulation between the different solid dielectrics first increases and then decreases with time during polarization and depolarization process. The electric field intensity in the solid domain is strengthened obviously under the polarity reversal voltage. The accurate interface charge simulation provides an effective reference for DC cable terminal insulation design.