Sumitomo Electric Industries has completed two high-voltage direct current (HVDC) interconnector cable projects using crosslinked polyethylene (XLPE) insulated cables.
The first project involved construction of a 400kV HVDC XLPE environment friendly cable system, which is claimed to be the highest voltage in the world for an HVDC-XLPE cable system, for NEMO Link.
The 1GW Nemo Link interconnector, a joint venture between National Grid in the UK and ELIA in Belgium, connects the electricity systems of the UK and Belgium via subsea cables.
In addition to increasing security of power supply for both countries, the new interconnection allows the import and export of electricity while supporting the integration of renewable energy in the grid.
Sumitomo said in a statement: “The cable system also features a high allowable operating temperature, which allows Nemo Link to have extra safety margin during cable operation, especially in cases where an unforeseeable situation creates excess current flows in the cable system or excess cable burial depth occurs due to sand wave mobility on the seabed.”
Sumitomo Electric subsidiary J-Power Systems has delivered the project as part of engineering, procurement and construction (EPC) contract awarded in June 2015 by NEMO Link.
Additionally, the firm has delivered the second project which involved construction of 250kV Hokuto-Imabetsu HVDC Link connecting Hokkaido and Honshu, to Hokkaido Electric Power Company (HEPCO).
The Hokuto-Imabetsu HVDC Link with 250kV HVDC XLPE cable is expected to increase transmission capacity between Japan’s main island Honshu and Japan’s northern island Hokkaido.
HEPCO has constructed the new 300MW Hokuto-Imabetsu HVDC Link, connecting Hokuto Converter Station in Hokkaido and Imabetsu Converter Station in Honshu in order to secure stable power supply.
Following commercial operation in March 2019, the project increased the total transmission capacity between Hokkaido and Honshu from 600MW to 900MW.
Sumitomo said: “With the increasing capacity of renewable energy sources and the necessity of long-distance power interconnectors for efficient use of such renewable energy between countries and regions, HVDC cable technology, which is suitable for long-distance power transmission, has been gaining significant attention in international markets.”