Characterisation of acoustic signal and pattern recognition of free moving metallic particle motion modes in GIS

Abstract

Free metallic particles, inside gas insulated switchgear (GIS) apparatus are considered hazardous to the insulation system, can be detected using acoustic sensors placed on the enclosure. From acoustic measurements, it is rather easy to determine the partial discharge pulses caused by loose or fixed particles. One can readily recognise the motion modes of the free particles by studying the acoustic signal. This paper presents the analysis of free metallic particle motion modes in GIS apparatus from acoustic measurements. The parameters such as maximum acoustic amplitude, number of acoustic pulses, mean value of maximum amplitude of 10 measurements, number of pulses which exceed the specified % of maximum amplitude characterising partial discharge activity of Al as well as Cu particles of different shapes are investigated.