Study on magnetic-induced disturbances of the ground potential

In this article the disturbances of the ground potential induced by the magnetic field generated by three-phase power cables have been studied. The electric current flowing into the power cables generates a varying magnetic field that may induce an electric disturb in a ground cable near the power cables. This disturb may affect any measurement performed with electronic instrumentation, since it requires a stable ground reference.Some 2D COMSOL ^® simulations have been carried out for different geometrical configurations of the cables aiming at finding the optimal solution in terms of minimum emitted magnetic field and induced current on the ground cable; the configurations that showed the best performances in terms of low disturbances have been further tested in the laboratory. The measurement of the level of the magnetic field and the induced current on a closed loop (simulating the zero-potential cable) confirmed the simulation results thus allowing for the selection of an optimal configuration which is also suitable for a practical realization.