Dielectric behaviour of cross-linked polyethylene for HVDC cables

In order to ensure the energetic transition, the electrical network is changing to connect renewable energy production sites and countries together. HVDC systems used in the last decades allow to interconnect countries and connect high power production sites sometimes far from shore. The constant growth of high voltage direct current networks brings about improvements in several fields. With a view to reducing costs of impregnated paper insulation cable manufacturing, companies also thought of extruded insulation for HVDC cables. In this system, the increase in the operating voltage and lifetime is determined by the ability to keep low level of space charges trapped in the cross-linked polyethylene matrix, which requires to improve its characteristics [1,2].