Modelling of partial discharge behavior at DC applied voltage by using ABC model

The increased application of HVDC components leads, at the same time, to forced usage of Partial Discharge (PD) measurement as an important tool for quality testing and reliability. Current issues are missing relations between the PD behaviour caused by insulation defects and the measured PD parameter as well as requirements for appropriate PD measuring systems. The adequate modelling of PD behaviour under DC conditions could improve that situation and might lead to deeper understanding of physical PD processes within the insulation. The paper deals with the modelling of partial discharge behaviour at DC condition by using a modified three capacitances (abc) model and compares it with its behaviour at AC applied voltage. The improved model has been used to study the effect of temperature, applied voltage, and void dimensions on partial discharge behaviours within a cylindrical void inside XLPE insulating material. The results show that under DC, the temperature rise will greatly affect the repetition rate, while the magnitude of the applied voltage is of higher influence in the case of AC. Also, the results show the magnitude of PD increases with higher void size, and the larger effect is the increase of the void radius.