Analysis of real kilometric three-core armoured cables by means of an integral multiconductor three-dimensional model

In this paper, a procedure based on three-dimension matrices is presented: it is the generalization of multiconductor cell analysis to any transmission line where the positions of all the active and passive conductors may change with continuity along their development. A meaningful example of this is given by three-core single lead-screened armoured cables where cores and armour wires are wound helically with different lay lengths. The computational complexity of this novel method is shown in comparison with the finite element method commercial software FLUX 3D which takes 70 h for meshing and solving a 3 m long model. On the contrary, the present matrix algorithms take from minute fractions to maximum 2 minutes (depending on subconductor number) to obtain results having negligible differences with respect to those obtained by means of FEM FLUX 3D ones if paramagnetic materials are involved and differences up to maximum 7 % with ferromagnetic ones (which implies, for submarine cable installations, a current rating computation difference lower than 3%).