New developments within the area of extruded HVDC cables

A new 525 kV DC cable system with a power rating range up to powers above 2 GW has been developed for both subsea and underground applications. The extruded HVDC cable system technology is appropriate when power needs to be efficiently delivered through populated or environmentally sensitive areas, or in coastal and open-sea applications. HVDC cable links are essential components of sustainable energy systems to connect energy markets and transmit vast amounts of electricity over very long distances, across or between continents. The successfully tested extruded 525 kV HVDC cable system is the result of long-term focused innovative R&D work across business units and corporate research centers and collaboration with a material manufacturer. This system utilizes a new cross-linked polyethylene (XLPE) DC insulation material, an oil- and porcelain-free termination based on wall bushing technology as well as a land joint and a flexible sea joint. This paper describes the product development including challenges and solutions, for the cable as well as the accessories, the extensive testing procedures and what the cable system is able to do.