Abstract
The reliable estimation of a flexible foundation model and the state of unbalance (both amplitude and phase) of a turbogenerator from machine rundown measured vibration data is an active research area. Earlier studies on the estimation of both these quantities used the whole frequency range of the rundown as a single band. However, such an identification may be inaccurate for large flexible foundations having many modes in the rundown frequency range. For reliable identification, the whole frequency range has to be divided into a number of frequency bands and the frequency-dependent foundation models have to be estimated together with the unbalance. This paper combines the unbalance estimation with the split frequency range for the foundation model, and the highlights the limitations observed during estimation of foundation models and the slate of unbalance. It is shown that the accuracy of the method may be enhanced by judicious choice of a weighting function. Having established the method in simulation, experimental data from a 3-m long test rig, with four journal bearings, is used to test the method. The approach seems to give reliable estimates of the machine unbalance.
Original language | English |
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Pages (from-to) | 416-421 |
Number of pages | 5 |
Journal | Journal of Engineering for Gas Turbines and Power |
Volume | 126 |
Issue number | 2 |
DOIs | |
Publication status | Published - Apr 2004 |