Impacts of temperature on the distribution of electric-field in HVDC cable joint

Impacts of temperature on the distribution of electric field in high voltage direct current (HVDC) cable joint have been investigated with COMSOL Multi-physics. The simulation of electric field under combined thermal-electrical conditions was carried out on a three-dimensional joint model, in which constant dc voltage and combined dc/impulse voltage were applied on the cable core while the temperatures of conductor were 298K, 333K and 363K respectively. The results show that the maximal field in the model and the tangential field on XLPE/SR interface increase a lot with the temperature increasing under dc voltage, and the position of maximal field changes from the head of high-voltage screen to the head of stress cone. When applied with combined dc/impulse voltage, the maximal field distribution appears at three different points in cable joints.