Characteristics Analysis of Acoustic Partial Discharge in Cable Defects

Acoustic analysis is a substantial method for identification of the defects in high tension cables. High tension underground cable defects are worth detection using acoustic sensors that exhibit different signatures at various defects. This paper presents characteristics analysis of cable defects using the sounds originated from the defects' partial discharge. Acoustic wave-forms of partial discharge are acquired and analyzed. Time-domain and spectral features were extracted from waveforms to determine the characteristic of the defects. Later, these features evaluated with discriminant analysis to examine their significance in the classification of the one defect from the other ones. Real cable termination acoustic data were used in the study, in which sounds in cable cut case at two voltage levels. The best features, in time domain, sound peak and energy, and in spectral domain, centroid and flux, yield 100% accuracy in discriminating these classes of waveforms.