Analysis of power system transient induced radiation for substation plant condition monitoring

Electromagnetic radiation in the form of atmospheric radio waves (or sferics) originate from power system apparatus when transient currents are present. This phenomenon can occur during switching events in substations where an arc forms part of the current path, causing nonlinearities. An experimental investigation over a two-year period has collected data from sferics induced by power system substation switching transients. The paper introduces analysis techniques to extract information from the received switching transient induced sferics and to allow event identification. Digital signal processing (DSP) is used to investigate the time- and frequency-domain characteristics of the experimentally recorded signals. The possible future application of the developed techniques for condition monitoring of substation switchgear is discussed.