Recent Developments in Electro-Thermal Life Modelling of HVDC Cables 2026 Thomas W. Dakin Distinguished Technical Contributions Award Keynote Lecture

This paper aims at showing recent developments in electro-thermal life and reliability modelling of HVDC cables, with focus on the contributions by the author. A theoretical background highlights the IPM-Arrhenius life model for constant electrical and thermal stress - a reference of main Standards for HVDC cables - cast into a statistical framework to treat insulation volume enlargement and HVDC cable system reliability, and used for Accelerated Life Test data fitting on Polypropylene blends. The IPM-Arrhenius model is also included in an algorithm for life and reliability estimation of HVDC cables under transient electric and thermal stresses, and an improved version of the algorithm based on a novel approach to the IPM is described. Later, some applications made possible by recent developments of this algorithm are shown, including: a comparison of the IPM-Arrhenius with the physical DMM life model for HVDC cables subjected to Type Test load cycles; a comparison between the macroscopic approach to electrical conductivity and the microscopic one relying on a Bipolar Charge Transport model; some estimates of the life of HVDC cables subjected to transient voltages, such as long Temporary Over-Voltages and Superimposed Switching Impulses. These latter are compared with the outcomes of aging tests on polymeric insulation subjected to DC plus transient voltage. A final discussion emphasizes the limits of these life modelling tools and singles out possible innovative avenues for future research.