Multiple partial discharge source discrimination in a high voltage transformer winding

Partial discharge (PD) analysis is an important technique for diagnosis and online monitoring of transformer insulation systems. PD within transformer windings may be due to several causes such as manufacturing defects, degradation of the primary insulation or contamination of the oil. The degradation processes occurring in dielectric insulation components can lead to development of different types of PD source [1], [2]. Multiple PD sources induced by different defects can be simultaneously present within the transformer winding. Therefore, it is necessary to develop tools to separate measurement data from multiple PD sources in order to facilitate separate PD source identification and location to allow accurate condition assessment of the winding.