Title :
Turboalternator shaft voltage measurements
Author :
D´Antona, Gabriele ; Pennacchi, Paolo ; Pensieri, Claudio ; Rolla, Carlo
Author_Institution :
Dept. of Energy, Politec. di Milano, Milan, Italy
Abstract :
This paper presents the results of shaft voltages measurement campaign undertaken to investigate the sources of unrecoverable temperature drift observed on the thrust bearing of a small industrial steam turbine of a turbogenerator installed in a cogeneration biomass thermal power station. The bandwidth of the shaft voltage signal recorded and the characteristic time evolution have pointed out the electrostatic charges produced by the turbine steam as the source of the shaft voltage. The study have shown that in this specific plant dangerous shaft voltages can settle in case of a bad shaft to ground connection, originally assured by a grounding brush installed inside the turbine bearing casing only.
Keywords :
alternators; cogeneration; earthing; electrostatics; machine bearings; shafts; steam turbines; thermal power stations; turbogenerators; voltage measurement; cogeneration biomass thermal power station; electrostatic charge; grounding brush; shaft voltage signal bandwidth recording; shaft-ground connection; small industrial steam turbine; thrust bearing; turbine bearing casing; turboalternator shaft voltage measurement; turbogenerator; unrecoverable temperature drift source; Brushes; Current measurement; Electrostatics; Resistance; Shafts; Turbines; Voltage measurement;
Conference_Titel :
Applied Measurements for Power Systems (AMPS), 2012 IEEE International Workshop on
Conference_Location :
Aachen
Print_ISBN :
978-1-4673-1540-1
DOI :
10.1109/AMPS.2012.6344002
