Thermal transient effects on space charge dynamics in HVDC extruded cable insulation

With the development of HVDC transmission systems, the impact of space charge accumulation in the insulation has attracted more attentions and the electric field distribution within the main insulation has become the focus point of research. In this paper, a bipolar charge transport model was applied to simulate the space charge behavior within the HVDC cable polymeric insulation. Based on many experimental observations, a threshold electric field at which the charge injection takes place was introduced to the model. Considering the practical operation of HVDC cables, a transient temperature distribution across the insulation was implemented to compute the charge generation and transportation processes. The simulation results suggest that the thermal transient has specific effects on charge dynamics in the cable insulation.