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Experimental Modal Analysis of Stator Overhangs of a Large Turbogenerator

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DOI: 10.4236/epe.2011.33028    10,002 Downloads   16,377 Views   Citations

ABSTRACT

Modal analysis of engg. structure for comprehending/resolving the vibration related issues/problems are well known. Two classical techniques-analytical (Finite Element Method-FEM) and experimental (Impact testing/Natural Frequency Test-NFT/Bump test) are generally used as complementary as well as stand-alone depending on the time, nature of structure, availability of the analysis tools, cost etc. In the present study, experimental technique was used in mitigating the endwinding vibration problem of a turbogenerator. In one of the Turbogenerators of 50 Hz variant, an increasing vibration trend was observed with system frequency sweep in almost whole of the endwinding basket particularly more on exciter end during sustained short / open circuit conditional runs. Experimental modal analysis was carried out of the overhangs. Frequency response functions (FRFs) were generated in local and global modes. The analysis thereon indicated global resonance of stator overhangs. Accordingly, appropriate remedial measures were planned and implemented. Consequently, global resonance frequency was shifted to higher zone, which in turn, resulted into substantial reduction in endwinding vibration levels.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

R. Sewak, R. Ranjan and V. Kumar, "Experimental Modal Analysis of Stator Overhangs of a Large Turbogenerator," Energy and Power Engineering, Vol. 3 No. 3, 2011, pp. 221-226. doi: 10.4236/epe.2011.33028.

References

[1] K. Senske, S. Kulig, J. Hauhoff and D. Wünsch “Vibrational Behaviour of the Turbogenerator Stator End Winding in Case of Electrical Failures,” Conférence Internationale des Grands Rèseaux Electriques, Yokohama , October 1997.
[2] D. Lambrecht and H. Berger “Integrated End-winding Ring Support for Water-Cooled Stator Winding,” IEEE Transactions on Power Apparatus and Systems, Vol. PAS-102, No. 4, 1983, pp. 998-1006. doi:10.1109/TPAS.1983.317815
[3] L. Intichar, “Eigenfrequenz-und Eigenformbestim-mung an Generator-Wickelk?pfen,” Symposium Schw- ingungsdiagnose an Kraftwerksturbos?tzen, 2006.
[4] Dipl.-Ing. Detlev Frerichs, “überwachung der Wickel- kopf schwingungen von Generatoren mit faseroptischen Beschleunigungsaufnehmern Schwingungsdiagnose an Kraftwerksturbos?tzen, 2006.
[5] R. Sewak, R. Ranjan and A. K. L. Rao, “Intricate Aspects of Turbogenerator Endwinding Vibration Monitoring Based on Data Analysis,” International Conference on Condition Monitoring and Diagnosis, Beijing, 21-24 April 2008, pp. 130-135. doi:10.1109/CMD.2008.4580247
[6] D. Shally, M. Farrell and K. Sullivan, “Generator End Winding Vibration Monitoring,” 43rd International Universities Power Engineering Conference, Padova, 1-4 September 2008, pp. 1-5. doi:10.1109/UPEC.2008.4651488

  
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