Clustering plots for the separation of partial discharge sources based on amplitude, charge and energy of PD pulses

It is almost always the case that multiple partial discharge (PD) sources are active in high-voltage equipment as a result of insulation defects or ageing. Therefore, over the years, different clustering techniques have been tested and used, so that each individual PD source can be separated and subsequently recognized, e.g. by means of the phase resolved PD patterns (PRPD)[1].