Investigations into electromagnetic emissions from power system arcs

Impulsive electromagnetic radiation can originate from many diverse sources in power systems when arcing occurs. The emission of radio wave energy in the form of a power system sferic in a similar way to lightning induced sferics is related to the non-linear properties of the plasma arc. This paper describes research work investigating the electromagnetic emissions in the very low frequency (VLF) and very high frequency (VHF) frequency bands from power system arcing events. Sources of power system sferics and the inducing mechanism are detailed. The characterisation of different types of power system arcing events recorded during experimentation are also discussed. The principles allowing power system arcing fault induced sferics to be discriminated from other impulsive noise sources and the location of the sferic´s origin are outlined. Finally the practical implementation of a real-time fault monitoring system and recorded results are presented