Nexans successfully qualifies a 525 kV submarine HVDC cable system with high power carrying capability

• Nexans, a global leader in the design and manufacturing of cabling systems and services, has recently qualified a new cable system that holds a higher capacity for electricity, paving the way for the expansion of offshore wind farms globally
• While Nexans’ technology is based on over a decade of full-scale extruded HVDC cable system development, this new qualification features a higher rated conductor temperature at 80°C.
• The cable system includes two factory joints, a landfall joint, a repair joint, outdoor sealing ends and gas insulated switchgear (GIS) sealing ends

Nexans has recently qualified a new 525 kV submarine cable system through a one year Pre-qualification test according to IEC 62895/Cigré TB 496 standards. The global market demand for large scale submarine high voltage direct current (HVDC) cable connections, for offshore wind farms and interconnections, foresees tremendous growth. With power carrying capacity upwards of 2 GW and beyond, HVDC cable systems will enable a more renewable driven future by balancing electricity supply and demand over vast geographical areas, or by connecting large, remote offshore wind farms to the grid.

Nexans HVDC cable system is based on a triple extruded cross-linked polyethylene (XLPE) insulation design. Integrated fiber-optic elements inside the cable allow for monitoring key system parameters. The cable system includes two factory joints, a landfall joint, a repair joint, outdoor sealing ends and gas insulated switchgear (GIS) sealing ends Routine and sample tests were performed, and additionally the complete set-up was mechanically preconditioned according to submarine cable standards. Thereafter followed by a yearlong electrical test according to Cigré TB 496, superimposed lightning/switching and examination of all test objects. This intensive program demonstrated the robustness and reliability of Nexans HVDC cable systems.

Using HVDC cable technology will provide significant advantages for transmitting large quantities of electricity at long distances thanks to improved load capacity, minimized losses, and a reduced cable footprint compared to conventional alternating current (AC) cable systems. While Nexans’ technology is based on over a decade of full-scale extruded HVDC cable system development, having achieved a 525 kV underground qualification in 2018, this new qualification features a higher rated conductor temperature at 80°C. This technological achievement allows Nexans to offer more reliable and competitive products, with turnkey solutions enabling large scale energy transmission.