HVDC links are mainly used for the transmission of large amounts of power over a long distance with low losses, especially for offshore generation sites that are far from shore (>70km). HVDC submarine cables are typically single-core cables with extruded insulation and metallic radial water barrier.
ZTT has the capability of manufacturing the HVDC submarine cables with an annual capacity of 1000km and had made a series of great achievements in Chinese market, including 160kV and 200kV projects for Nan Ao and Zhoushan islands. In 2019, ZTT was awarded a 400kV HVDC interconnector in Rudong county, Jiangsu province with a transmission capacity of 800 MW for offshore wind farm development.
CIGRE recommendations: CIGRE 496, CIGRE 623.
For offshore wind farm
-Export cable to transport the total generated power from offshore substation to onshore substation
For interconnection
-Interconnecting grids of countries
-Power supply from mainland to isolated islands
ZTT has the capability to manufacture long continuous length HVDC submarine cables without factory splices as it is equipped with the state-of-the-art VCV lines, vertical assembly lines with big carousels and enough outdoor storage carousels for completed cables. Moreover, the wharf is 80 meters from the storage carousels, which can minimize the risk during cable load out.