Magnetic field distributions below high-voltage power lines Package Magnum Input files PowerLine.xls, PowerLine000.CDF, PowerLine000.GIN, PowerLine060.CDF, PowerLine060.GIN Download PowerLine.zip Description A user wanted to calculate magnetic field levels on the ground near a high-voltage transmission line. In the Netherlands, there is a regulation that fields cannot exceed 0.4 microtesla in areas where children spend extended time. The user sent a text file of line segment coordinates of two 3-phase lines between towers (top figure). At 50 Hz, common soils have little effect on magnetic fields over scales comparable to the line height (15-20 m), so a free-space calculation gives good results. This example shows how to integrate user-supplied coordinates into a Magnum calculation in the Free mode. Results At the low frequency, a static-field code is suitable for the calculation. Magnum solutions were determined for several values of AC phase. The lower figure shows results from one of them. The filled-contour plot on the left gives the variation of |B| in a plane 1.0 m above the ground. The plot on the left shows contour lines of |B| = 0.4 microtesla in the plane. Comments This tutorial describes the calculations in detail: Magnetic field distributions below high-voltage power lines.