Field lines produced by transmission lines

These pictures show the field lines produced by typical transmission lines. The field lines are calculated for the instant in time when the current and voltage on the middle phase is zero.

This calculation is for a line with transposed phasing so the magnetic field lines have a quadrupole pattern with four “poles”. If the line had untransposed phasing there would only be two.

more detail on phasing

Magnetic fields are (basically) unaffected by the ground but electric fields are strongly perturbed by it and the electric field lines always meet the ground at right angles.

more detail on screening and perturbing fields

Examples of field lines produced by transmission lines

More detail on the different parts of a transmission line.

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