Dynamic characteristics of a rub-impact rotor-bearing system for hydraulic generating set under unbalanced magnetic pull
First Online: 22 November 2012 Received: 22 April 2012 Accepted: 07 November 2012 DOI:
Cite this article as: Zhang, L., Ma, Z. & Song, B. Arch Appl Mech (2013) 83: 817. doi:10.1007/s00419-012-0719-0 Abstract
Electromagnetic and mechanical forces are main reasons resulting in vibrations in hydraulic generating set. The non-symmetric air-gap between the rotor and stator creates an attraction force called unbalanced magnetic pull (UMP). The UMP can produce large oscillations which will be dangerous to the machines. In this paper, the nonlinear dynamic characteristics of a rotor-bearing system with rub-impact for hydraulic generating set under the UMP are studied. The rubbing model is established based on the classic impact theory. Through the numerical calculation, the excitation current, mass eccentricity, stiffness of shaft and radial stiffness of stator are used as control parameters to investigate their effect on the system, by means of bifurcation diagrams, Poincaré maps, trajectories and frequency spectrums. Various nonlinear phenomena including periodic, quasi-periodic and chaotic motions are observed. The results reveal that the UMP has significant influence in the response of the rotor system that the continuous increase in the excitation current induces the alternation of quasi-periodic and chaotic motions, the co-occurrence of oil whip and rub in a wide excitation range aggravates the vibration and leads to the instability of the system. In addition, the large eccentricity and radial stiffness of stator, as well as the small stiffness of shaft may lead to the occurrence of full annular rubbing while increasing the stiffness of the shaft can play an important role of suppressing the chaotic motion, reducing the vibration and improving stability of the system.
Keywords Hydraulic generating set Rotor-bearing system Rub-impact Unbalanced magnetic pull Nonlinear dynamics References
Wen B.C.: Survey concerning in recent research of nonlinear dynamics of rotating machinery with faults. J. Vib. Eng.
17(s), 1–5 (2004)
Perers R., Lundin U., Leijon M.: Saturation effects on unbalanced magnetic pull in a hydroelectric generator with an eccentric rotor. IEEE Trans. Magn.
(10), 3884–3890 (2007)
Huang Z.W., Zhou J.Z., Kou P.G. et al.: Nonlinear electromagnetic vibration of rotor bearing system of hydropower unit. J. Huazhong Univ. Sci. Tech. (Nat. Sci.)
38(7), 20–24 (2010)
Fu Z.Q., Li J.J.: Determination of load field current for synchronous machines. Large Electr. Mach. Hydraul. Turbine
5, 11–15 (2003)
Li, Y.G., Li, H.M., Zhao, H.: The new criterion on inter turn short-circuit fault diagnose of steam turbine generator rotor windings. Chin. Soc. Electr. Eng.
23(6), 112–116, 119 (2003)
Zhu Y.B., Hong S.S.: Vibration analysis of shaft No. 10 for generator No. 1 in Pingwei power plant. Electr. Power
33(10), 45–47 (2000)
Ma Z.Y., Dong Y.X.: Dynamics of Water Turbine Generator Set. Dalian University of Technology Press, Dalian (2003)
Cameron J.R., Thomson W.T., Dow A.B.: Vibration and current monitoring for detecting airgap eccentricity in large induction motors. Proc. IEE B
(3), 155–163 (1986)
Yu K.S.: The study and improvement for the contact fault between the air gap of the stator and rotor of the bulb tubular hydrogenerators. Large Electr. Mach. Hydraul. Turbine
3, 8–16 (1996)
Pollock G.B., Lyles J.F.: Vertical hydraulic generators experience with dynamic air gap monitoring. IEEE Trans. Energy Convers.
(4), 660–668 (1992)
Beatty R.F.: Differentiating rotor response due to radial rubbing. J. Vib. Acoust. Stress Reliab. Des.
(2), 151–160 (1985)
Ehrich F.F.: Some observations of chaotic vibration phenomena in high-speed rotordynamics. J. Vib. Acoust.
(1), 50–57 (1991)
Muszynska A., Goldman P.: Chaotic responses of unbalanced rotor/bearing/stator systems with looseness or rubs. Chaos Solitons Fractals
(9), 1683–1704 (1995)
Lin F., Schoen M.P., Korde U.A.: Numerical investigation with rub-related vibration in rotating machinery. J. Vib. Control
(6), 833–848 (2001)
Chu F., Zhang Z.: Bifurcation and chaos in a rub-impact Jeffcott rotor system. J. Sound Vib.
(1), 1–18 (1998)
Chu F.L., Lu W.X.: Experimental observation of nonlinear vibrations in a rub-impact rotor system. J. Sound Vib.
, 621–643 (2005)
Dai X.J., Dong J.P., Zhang X.J.: Effects of unbalances on the rotor/stop rubbing. Chin. J. Mech. Eng.
(6), 90–93 (2001)
Feng Z.C., Zhang X.Z.: Rubbing phenomena in rotor–stator contact. Chaos Solitons Fractals
(2), 257–267 (2002)
Qin W.Y., Chen G.R., Meng G.: Nonlinear responses of a rub-impact overhung rotor. Chaos Solitons Fractals
(5), 1161–1172 (2004)
Zhang W.M., Meng G.: Stability, bifurcation and chaos of a high-speed rub-impact rotor system in MEMS. Sens. Actuators A
(1), 163–178 (2006)
Shen X.Y., Jia J.H., Zhao M.: Effect of parameters on the rubbing condition of an unbalanced rotor system with initial permanent deflection. Arch. Appl. Mech.
(12), 883–892 (2007)
Shen X.Y., Jia J.H., Zhao M.: Numerical analysis of a rub-impact rotor-bearing system with mass unbalance. J. Vib. Control
(12), 1819–1834 (2007)
Chang-Jian C.W., Chen C.K.: Chaos of rub-impact rotor supported by bearings with nonlinear suspension. Tribol. Int.
(3), 426–439 (2009)
Cao J.Y., Ma C.B., Jiang Z.D. et al.: Nonlinear dynamic analysis of fractional order rub-impact rotor system. Commun. Nonlinear Sci. Numer. Simul.
(3), 1443–1463 (2011)
An X.L., Zhou J.J., Xiang X.Q. et al.: Dynamic response of a rub-impact rotor system under axial thrust. Arch. Appl. Mech.
(11), 1009–1018 (2009)
Gustavsson R.K., Aidanpää J.: Evaluation of impact dynamics and contact forces in a hydropower rotor due to variations in damping and lateral fluid forces. Int. J. Mech. Sci.
(9–10), 653–661 (2009)
Huang Z.W., Zhou J.J., Yang M.Q. et al.: Vibration characteristics of a hydraulic generator unit rotor system with parallel misalignment and rub-impact. Arch. Appl. Mech.
(7), 829–838 (2011)
Jordan H., Schroeder R.D., Seinsch H.O.: Zur Berechnung einseitig magnetischer Zugkräfte in Drehfeldmaschinen. Archiv fur Elektrotechnik
(2), 117–124 (1981)
Ohishi H., Sakabe S., Tsumagari K. et al.: Radial magnetic pull in salient pole machines with eccentric rotors. IEEE Trans. Energy Convers.
(3), 439–443 (1987)
Guo D., Chu F., Chen D.: The unbalanced magnetic pull and its effects on vibration in a three-phase generator with eccentric rotor. J. Sound Vib.
(2), 297–312 (2002)
Adiletta G., Guido A.R., Rossi C.: Chaotic motions of a rigid rotor in short journal bearings. Nonlinear Dyn.
(3), 251–269 (1996)
Xu S.Z.: Electromechanics. Chinese Machine Press, Beijing (1988)
Pennacchi P., Frosini L.: Dynamical behaviour of a three-phase generator due to unbalanced magnetic pull. IEE Proc. Electr. Power Appl.
(6), 1389–1400 (2005)
CrossRef Copyright information
© Springer-Verlag Berlin Heidelberg 2012