Submarine power cable

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Submarine power cables are cables for electrical power running through the sea, below the surface.

A DC system may use the ground and seawater as a return path for current. However, this cannot be always practiced because of disturbances to magnetic compass systems on vessels crossing the cable and because of ecological effects of electrochemical reactions at the electrodes. Also, the impedance of the water and other things in the return path might be high.

The length of undersea AC cables is restricted by the capacitance between the active conductors and the surrounding metallic shield. If the cable were to be made long enough, the reactive power produced by an AC cable would take up the entire current carrying capacity of the conductor, so no usable power would be transmitted. Therefore, for transmission of large amounts of electric power through long submarine cables, direct current (DC) is preferred over AC, because DC cables require no reactive power. As well, for three phase AC-cables three conductors are necessary, while for DC only 1 or 2 conductors are required.

Contents

[edit] Submarine cables for AC

[edit] Submarine cables for DC

[edit] Longest

[edit] See also