Assessed condition trending system (ACTS) a tool for generator on-line diagnostics

A powerful tool for unit diagnostic monitoring has been developed which provides a reliable assessment of stator winding insulation condition by using analysis results from on-line partial discharge (PD) measurements. The main features and advantages of this permanently installed continuous PD monitoring system that includes real time assessed condition trending and alarm initiation capability will be presented. The objective is to identify and evaluate condition changes of the stator winding insulation system and thus to improve condition-based and predictive maintenance strategies. This effectively reduces the overall total lifecycle cost of the unit. Examples are given where based on the assessment of on-line PD measurements on turbogenerators machines were shut down in order to avoid premature failure and to allow for corrective maintenance work to be performed.