Numerical analysis of thermo-electric field for 10 kV AC XLPE cable in DC operation

In this paper, a thermo-electric field coupling model was established to perform simulations on a typical three-core AC 10 kV XLPE cable in bipolar DC operation by the finite element analysis software ANSYS. The obtained results showed that when the conductor temperature of the cable was 70
^o
C and the cable was laid in the environmental temperature of 40 °C, the estimated cable ampacity could reach up to 440 A. The maximum of electric field in the cable insulation was settled below 3 kV/mm to minimize the effect of space charge for the cable in DC operation. It was found that the cable could run at the bipolar DC ± 10 kV with enough safety margin. Moreover, the maximum transmission power of the cable running at the bipolar DC ± 10 kV mode was 1.37 times of the power in the AC operation. It is promising for upgrading the present AC grid into future DC grid.