Diagnosis of Multiple Defects Within Large Hydroelectric Generator Using Stray Flux and Air Gap (Distance and Flux) Measurements

This paper presents the analysis of both stray and air gap magnetic flux measurements within large hydroelectric generators. The study demonstrates the similarities and differences between these two types of measurements when used in the development of diagnosis and remedial strategies. The radial and tangential components of the stray flux are also shown at different measurement locations around the hydroelectric generators. The measurement approach employed in this study was able to detect electrical and mechanical failure mechanisms in hydroelectric generators such as rotor eccentricity (static or dynamic), rotor ellipticity and interturn short circuit (ITSC)in the rotor windings (Bernier et al. 2023). The approach was validated using measurements taken within nine large hydroelectric generators operating at different powers and load conditions.