Loss reduction in cable sheathing

Abstract

In order to reduce electric potential difference

between the sheathings of single core three-phase cables, the

sheathing is grounded and bonded at one or both ends of the

cables. If the cable is long, double bonding has to be carried out

which leads to circulating currents and increased power loss.

Based on finite element (FE) calculations, this paper shows, that

raising the sheath’s resistance, by decreasing its cross section and

increasing its resistivity, can significantly reduce this loss. The

magnetic field close to the ground surface and the behaviour of

the cable during fault conditions are also investigated.