Loss-of-Life Fraction Estimation for HVDC Extruded Cables in the Presence of Long Temporary Overvoltages Recorded in the Field

The present paper has the goal of loss of life estimation of XLPE-insulated cables subject to long temporary overvoltage (TOV) measured in the field on the healthy pole of an HVDC cable link during a fault on the other pole. First, the temperature profile within the cable insulation is calculated at steady state. Then, the electric field during the voltage transient is computed using a macroscopic conduction model. The loss-of-life fraction is evaluated based on the electrothermal life model at 5 points within the insulation. Results show that the greatest percentage of the loss of life is noticed during the peak and during the plateau of the TOV. However, the loss of life is negligible during the transient, hence the cable can be said to be resilient to the considered contingency.