Broadening the simulative analysis of the effects of long temporary overvoltages on the reliability of HVDC cables

Long Temporary Over-voltages (TOVs) due to pole-to-ground faults occur in HVDC cable transmission systems with VSC. Preliminary experimental and numerical studies of the possible adverse effects of these long TOVs on HVDC extruded insulation cables have been started by the authors, focusing on one single DC-XLPE insulated 320-kV case-study cable for the simulative analysis. This paper aims at broadening the simulations, by extending the previously-developed method for the estimation of the effects of long TOVs on HVDC cable reliability to other types of DC-XLPE insulated cables with the much higher rated voltage of 600 kV and larger conductor cross-section. The results obtained here for these new cable designs essentially confirm what already obtained for the 320-kV cable.