Underground power cables in urban areas: a simple technique for the passive shielding of the magnetic field

In this paper the authors propose a parametric analysis in order to estimate the magnetic pollution due to typical flat configurations of underground power cable lines layed in urban areas. They also investigate the performances of open or closed shields, made of conductive or magnetic materials, in order to reduce the magnetic pollution due to existing installations or new installations. Numerical procedures, based on a finite element model, are applied to develop efficient shielding techniques in a real-life example, consisting of a typical flat configuration of a three phase 150 kV underground power cable line placed in an urban area. Finally, an attempt to carry out new criteria and guidelines for the optimal design of simple shielding configurations has been made.