Lightning electric‐field waveforms associated with transmission‐line faults

The radiated electric field produced by lightning plays a vital role in lightning location systems (LLSs). The presence of the elevated objects, i.e. transmission lines in the presented study, result in an increase of amplitude and multiple sub-peaks in the observed electric fields. On the basis of the electric fields obtained from multiple sensors of Foshan total LLS, electric fields from nine negative lightning strokes associated with transmission-line faults at a distance of 10-86 km in Foshan area were examined in detail, which were adopted to make comparison with the radiated electric fields from natural negative cloud-to-ground lightning detected nearby within 1 min. It can be found that the arithmetic means (AMs) of initial electric-field peak values of waveforms associated with transmission-line faults are about twice those of natural negative lightning and the second and third sub-peaks can be identified obviously. In addition, the correlation between electric-field waveform characteristics and propagation distance was validated. The AM zero-crossing time, fast-transition 10-90% rise time and the time interval between sub-peaks slightly increase with distance.