Classification of partial discharge sources by the characterization of the pulses waveform

Partial discharges phenomenon (PD) is one of the most relevant degradation modes that affects in the gradual deterioration of the insulation elements in high voltage (HV) electrical systems, thus PD measurement is essential for their condition assessment. In the last decades on-line PD measurements have become a common technique for assessing the insulation condition of installed HV installations, although in on-line tests it is difficult to perform accurate diagnoses due to the existence of high levels of background noise and in many cases of more than one source of pulse-shaped signals. In order to overcome the difficulties mentioned, this paper proposes a method for the classification of PD signals based on a mathematical modeling. With the proposed model, representative parameters associated to the waveform of each pulse acquired are calculated so that they can be separated in different clusters. Furthermore, this mathematical model enables the reconstruction, generally with a reasonable accuracy, of the measured signals in HV installations. This approach permits to save the pulse data of a test with a low requirement of memory capacity in comparison with other approaches, that need to save all samples of each recorded pulse to visualize them and for further analysis or post-processing.