The invention discloses a direct-current
submarine cable for flexible
power transmission. The direct-current
submarine cable is characterized by comprising two direct-current units, a liner layer is lapped outside the two direct-current units, filling strips are filled in gaps formed by the liner layer and the direct-current units, at least one flat armor layer is arranged outside the liner layer, and an outer wrapping layer is lapped outside at least one flat armor layer. Each of the direct-current units comprises a water blocking conductor, an inner shielding layer, an insulating layer and an outer shielding layer which are arranged successively from the inside to the outside. Semi-conductive water blocking tapes are lapped outside the outer shielding
layers, lead sheaths and protection sheaths are arranged outside the semi-conductive water blocking tapes successively, the insulating
layers are made of direct-current crosslinked
polyethylene, and the inner shielding
layers and the outer shielding layers are made of direct-current shielding materials. The direct-current
submarine cable has the advantages that the direct-current units are used, so that the
submarine cable is high in transmission efficiency and small in
line loss, long-distance large-capacity
power transmission is facilitated, the current can be adjusted easily, the
power transmission direction can be changed easily, and the stability is high; and the direct-current
submarine cable has a longer service life than that of an alternating-current
submarine cable.