Prediction of magnetic fields in multiconductor systems with significant harmonic currents

Electric and magnetic fields produced by transmission systems have received strong interest both for biological effects and for interference with electrical and electronic devices, measuring sets, computers, control systems, etc. More attention has been devoted to magnetic fields which are difficult to screen and which can be significant when produced not only by transmission but also by the distribution and utilization systems. The paper proposes a simplified approach which seems useful in the case of lines set up by cables and in particular when more cables are connected in parallel considering currents affected by significant harmonic content. Complete simulation results for several selected cases to analyze the electromagnetic field under a quasi stationary condition in a multiconductor system are reported and discussed in detail and the main results are summarized. It was found that the parallel connection of conductors can amplify or reduce magnetic field amplitude with respect to the single conductor case and that this effect depends on harmonic order.