Abstract:
Shaft voltages and currents are an unavoidable characteristic of rotating machines,
though they are typically a nuisance this work shows that shaft signals can be used
for fault diagnosis. This work focussed on shaft voltages present on synchronous
generators. Measurements on a 4-pole generator found that the angular position
of the shaft could be determined from the shaft voltage. An experimental 20 kVA
2-pole synchronous generator was designed and built which resembled a full-size
600 MVA turbo-generator. The effects of a static eccentricity on the shaft voltage
were successfully determined firstly through FEM simulation and then verified with
physical measurements. Shaft voltages can be used to diagnose static eccentricity,
future work should investigate other faults. In addition, computer simulation was
found to be effective and simulation and measurements of operating machines (such
as turbo-generators) should be considered.
