Assessment of the Technical Condition of Turbogenerators by Partial Discharges

Partial discharges (PD) have been studied for 50 years and their influence on the operation of electric machines is undeniable. The authors of the article conducted a study proving that an increase in PD activity over time (more pulses and larger pulses) indicates an aging of the stator winding insulation. It is possible to predict how seriously the condition of the winding has worsened long before an emergency failure occurs by knowing this. The article presents the results of PD measurements in the stator winding of a turbo-generator. It was decided to conduct a survey of the stator during the overhaul due to the change in the levels of PD in the process of monitoring. The survey confirmed the preliminary results of the analysis of PD which once again proves the necessity of such tests.