Magnetic Eddy-Current and Thermal Coupled Models for the Finite-Element Behavior Analysis of Underground Power Cables

We have modeled underground isolated power cables by using magnetic eddy-current (EC) and thermal coupled formulations solved by the finite-element method (FEM). The magnetic field equation expressed in terms of magnetic vector potential (MVP) is strongly coupled with the total current density equation, which includes the source and the EC densities for taking into account skin and proximity effects. The model uses the computed EC density of losses with electric conductivity temperature dependence introduced as a heat source in the free transient thermal equation completed by the convection heat transfer. We studied single and multicircuit three-phase arrangements at various cable spaces in order to analyze the magnetic flux density and the time-space temperature evolution.