Dielectric evaluation of stator bars in laboratory

Several common sources of discharges activity occurring on generators have been replicated in the laboratory under well-controlled conditions. Each source was evaluated individually and recorded with a phase resolved acquisition system and with a spectrum analyzer. The dominant features of each respective phase resolved partial discharge PRPD pattern are presented. The association of each well-defined type of discharge source, with its specific PRPD pattern, constitutes the basis of our database used for the discharge source recognition during generator diagnostics. The comparison of laboratory results with the PRPD present in IEC 60034-27-2 is summarized in this paper.