Using Simplified Models to Assist Fault Detection and Diagnosis in Large Hydrogenerators

Table 8

Comparison of measured and simulated vibrations in direction, in an LHG operating at speed-no-load, with an unbalance grade ISO G4.25 in the generator rotor, at the rotating frequency.

Journal bearing	Shaft relative vibrations [µ]			Bearing absolute vibrations [mm/]
	Measured	Simulated	Error	Measured	Simulated	Error [%]
Upper	40.5	41.0	1.2%	0.218	0.261	19.7%
Lower	38.3	38.6	0.8%	0.059	0.107	81.4%