In this paper, two-dimensional time-stepping finite-element (TSFE) method is performed for modeling and analyzing of a salient pole synchronous generator with different degree of dynamic eccentricity (DE) fault. TSFE analysis is used to describe the influence of DE fault on the flux distribution within the generator and no-load voltage profiles at low and high field current is obtained for healthy and faulty cases. Comparing the magnetic flux distribution of healthy and faulty generators helps to detect the influence of DE fault. Also, it can be seen at no-load condition with low excitation current, the effect of the eccentricity is considerable compared to that of the rated excitation current. Since the calculation of inductances of the machine is the most important step for fault analysis and diagnosis, the self- and mutual-inductances of the stator phases and rotor windings are calculated in the eccentric generator. Double periodic phenomenon is observed in inductances profile of stator phases due to the DE fault. Finally, spectrum analysis of stator current of two generators with different design parameters is used to diagnosis the significant harmonics in the presence of DE fault.
2. Faiz, J., B. M. Ebrahimi, and M. B. B. Sharifian, "Different faults and their diagnosis techniques in three-phase squirrel-cage induction motors --- A review ," Electromagnetics Journal, No. 26, 543-569, 2006.
3. Toliyat, H. A. and S. Nandi, "Condition monitoring and fault diagnosis of electrical machines --- A review," Proc. IEEE-IAS Annu. Meeting, 197-204, Phoenix, AZ, Oct. 1999.
4. Faiz, J. and I. Tabatabaei, "Extension of winding function theory for nonuniform air gap in electric machinery," IEEE Trans. Magnetics, Vol. 38, 3654-3657, 2002.
5. Faiz, J., I. Tabatabaei, and H. A. Toliyat, "An evaluation of inductances of a squirrel-cage induction motor under mixed eccentric conditions," IEEE Trans. Energy Conversion, Vol. 18, 252-258, 2003.
6. Nandi, S., H. A. Toliyat, and X. Li, "Condition monitoring and fault diagnosis of electrical motors --- A review," IEEE Trans. Energy Conversion, Vol. 20, No. 4, 719-729, Dec. 2005.
7. Tabatabaei, I., J. Faiz, H. Lesani, and M. T. Nabavi-Razavi, "Modeling and simulation of a salient-pole synchronous generator with dynamic eccentricity using modified winding function theory ," IEEE Trans. Magnetics, Vol. 40, No. 3, 1550-1555, 2004.
8. Tavner, P. J. and J. Penman, Condition Monitoring of Electrical Machines, Research Press, Letchworth, UK, 1987.
9. Toliyat, H. A. and N. A. Al-Nuaim, "Simulation and detection of dynamic air-gap eccentricity in salient-pole synchronous machines ," IEEE Trans. Industry Application, Vol. 35, No. 1, 86-93, 1999.
10. Hsu, J. S. and J. Stein, "Effect of eccentricities on shaft signals studied through windingless rotors," IEEE Trans. on Energy Conversion, Vol. 9, No. 3, 564-571, 1994.
11. Hsu, J. S. and J. Stein, "Shaft signal of salient-pole synchronous machines for eccentricity and shorted-field-coil detections," IEEE Trans. Energy Conversion, Vol. 9, No. 3, 572-578, 1994.
12. Kim, C. E. and J. K. Sykulski, "Harmonic analysis of output voltage in synchronous generator using finite element method taking account of the movement," IEEE Trans. Magnetics, Vol. 38, No. 2, 1249-1252, Mar. 2002.
13. Faiz, J., B. M. Ebrahimi, B. Akin, and H. A. Toliyat, "Finite-element transient analysis of induction motors under mixed eccentricity fault," IEEE Trans. Magnetics, Vol. 44, No. 1, 66-74, Jan. 2008.
14. Bangura, J. F. and N. A. Demerdash, "Effects of broken bars/end-ring connectors and airgap eccentricities on ohmic and core losses of induction motors in asds using a coupled finite element-state space method," IEEE Trans. Energy Conversion, Vol. 15, No. 1, 40-47, Mar. 2000.
15. Thomson, W. T., "On line current monitoring and application of a finite element method to predict the level of static air gap eccentricity in three-phase induction motors," IEEE Trans. Energy Conversion., Vol. 13, No. 14, 347-354, Dec. 1998.
16. Thomson, W. T. and A. Barbour, An industrial case study of on-line current monitoring and finte element analysis to diagnose air-gap eccentricity problems in large high voltage 3-phase induction motors, Proc. 9th Int. Conf. Electr. Machines Drives, Vol. 468, Conference Publication, 1999.
17. Faiz, J., I. Tabatabaei, and H. A. Toliyat, "An evaluation of inductances of a squirrel-cage induction motor under mixed eccentric conditions," IEEE Trans. Energy Conversion, Vol. 18, No. 2, 252-258, Jun. 2003.
18. Joksimovic, G. M., M. D. Durovic, J. Penman, and N. Arthur, "Dynamic simulation of dynamic eccentricity in induction machines --- Finding function approach," IEEE Trans. Energy Conversion, Vol. 25, No. 2, 143-149, Jun. 2000.
19. Nandi, S., R. M. Bharadwaj, and H. A. Toliyat, "Performance analysis of a three-phase induction motor under mixed eccentricity condition ," IEEE Trans. Energy Conversion, Vol. 17, No. 3, 392-399, Sep. 2002.
20. Nandi, S., S. Ahmed, and H. A. Toliyat, "Detection of rotor slot and other eccentricity related harmonics in a three phase induction motor with different rotor cages," IEEE Trans. Energy Conversion, Vol. 16, No. 3, 253-260, Sep. 2001.
21. Povinelli, R. J., J. F. Bangura, N. A. O. Demerdash, and R. H. Brown, "Diagnostics of bar and end-ring connector breakage faults in poly phase induction motors through a novel dual trackof time-series data mining and time-stepping coupled FE-state space modeling," IEEE Trans. Energy Conversion, Vol. 17, No. 1, 39-46, 2002.
22. Cundev, D. and L. Petkovska, "Computation of electromechanical characteristics of salient poles synchronous motor with damper based on FEM," Journal of Materials Processing Technology, Vol. 161, 241-246, 2005.
23. Faiz, J., B. M. Ebrahimi, and M. B. B. Sharifian, "Time stepping nite element analysis of broken bars fault in a three-phase squirrel-cage induction motor," Progress In Electromagnetics Research, Vol. 68, 53-70, 2007.
24. Faiz, J. and B. M. Ebrahimi, "Mixed fault diagnosis in three-phase squirrel-cage induction motor using analysis of air-gap magnetic field ," Progress In Electromagnetics Research, Vol. 64, 239-255, 2006.
25. Tu, X., L. A. Dessaint, M. E. Kahel, and A. O. Barry, "A new model of synchronous machine internal faults based on winding distribution," IEEE Trans. Industrial Electronics, Vol. 53, No. 6, 1818-1828, Dec. 2006.
26. Reichmeider, P. P., C. A. Gross, D. Querrey, D. Novosel, and S. Salon, "Internal faults in synchronous machines Part I: The machine model," IEEE Trans. Energy Conversion, Vol. 15, No. 4, 376-379, Dec. 2000.
27. Faiz, J., B. M. Ebrahimi, M. Valavi, and H. A. Toliyat, "Mixed eccentricity fault diagnosis in salient-pole synchronous generator using modified winding function method," Progress In Electromagnetics Research B, Vol. 11, 155-172, 2009.