The influence of void configuration in statistical parameters of partial discharge signals

Partial discharge measurement has long been used to evaluate insulation system design and as a quality assurance test for High Voltage (HV) apparatus prior to installation. PD is characterized by high frequency current pulses originating in gas ionization processes when damaged insulation is submitted to high values of electric field. PD process modeling allows a better understanding of the phenomena. The characterization of PD resulting from a single void in an insulation sample has been widely reported. The study of PD originating from multiple voids is, however, less common. In this paper, an evaluation of ten void configurations is reported. Well-defined insulation defect configurations were defined and the electric field of each configuration was simulated using finite elements method. Each configuration was reproduced using a physical PD generator developed for this and similar studies. The emulated PD was recorded using a classical PD measurement system. Statistical parameters have been calculated for each configuration.