An invariant diagnostic marker for the identification of partial discharge sources in electrical apparatus

The problem of the identification of Partial Discharge (PD) phenomena in electrical apparatus, where the PD signals detected at the measurement bus can be significantly attenuated and distorted by the transmission path, is dealt with. Recently, it has been shown that the shape parameter of the Weibull function, β, can be used to identify PD-source typologies, even in the presence of different PD phenomena simultaneously active. This paper provides further contributions to the validation of β as aging marker, focusing on the behavior of β in the presence of distortion and attenuation of PD signals due to the influence of the transmission path between the detection point and the PD source. For this purpose, different PD sources, such as internal void, surface and corona discharges, were considered in the experiments