End-Winding Vibration

Early Detection of Stator Winding Vibration is Key

Stator winding related defects are a major cause of forced outages in large rotating machines, hydro and turbo generators. Electrical insulation is one of the most important parameters influencing motor and generator reliability. High number of stator winding problems is attributable to vibration of end-winding or bars within the slots. Stator winding insulation integrity is perpetually ravaged by voltage stresses, mechanical forces and thermal effects encountered during normal day to day operation. This leads to the development of looseness and shrinkage of critical components supporting the end-winding resulting in vibration and subsequently, compromised insulation integrity and premature failure.

The ability to detect and monitor stator end-winding vibration from its early stages allows the administration of necessary counter measures to prevent catastrophic failure of the stator winding. By on-line monitoring of the stator end-winding vibrations, trending of the ageing process can be performed, and measures put in place before major damage or breakdown can occur. This way timely action can greatly optimize power plant equipment availability and reliability.