LF Electric and Magnetic Fields



The geomagnetic field has a low average amplitude H = 30 A/m. The magnitude and position of the poles change slowly over several hours (magnetic storms).

These slow changes also generate electric fields.

Since the rate of change of these fields is very low, induction in these fields is insignificant.

The exception is extensive, exposed systems, such as electric power systems where magnetic storms may involve significant current flows in power lines which can cause malfunction of protection relays