Preliminary Estimation of The Effect of Insulation Losses on HVDC Cable Reliability

Insulation losses in HVDC cables are mostly deemed negligible compared to conductor losses, but this might not always be the case, especially for innovative cable designs. This paper aims at a preliminary evaluation of the effect of insulation losses on the temperature rise in the insulation of HVDC XLPE-insulated cables subject to load cycles according to CIGRÉ Technical Brochure 496. The ultimate goal is finding the voltage values above which insulation losses lead to a non-negligible increase of insulation temperature, thereby affecting life and reliability of HVDC cables. The results show that the effect of insulation losses on the loss of life is deemed negligible. Thus, insulation losses can have an impact only on the thermal stability of cables, not on the loss of life itself.