ONLINE AND OFFLINE VIBRATION ANALYSIS OF STATOR END WINDINGS OF LARGE POWER GENERATORS

An overview of different techniques to monitor vibrations of the generator end winding (impact tests, online vibration measurements using fiber optic accelerometers or a laser vibrometer) are presented. Data from online vibration measurements to investigate the vibration modal shapes of the stator end winding basket during operation is correlated with the generator operation parameters. These analyses are compared to results of finite-element-model calculations of a stator end winding. To evaluate the vibrations of a generator stator end winding during operation, it is necessary to relate vibrational modes to the generator operation parameters. In situ recording of, i.e. local accelerations or strain together with generator operating parameters allows deeper insight into the correlation of operating parameters and vibrations of the stator end windings.