Flux linkage estimation based loss of excitation relay for synchronous generator

Flux linkage estimation based loss of excitation relay for synchronous generator

For access to this article, please select a purchase option:

Buy article PDF
(plus tax if applicable)
Buy Knowledge Pack
10 articles for $120.00
(plus taxes if applicable)

IET members benefit from discounts to all IET publications and free access to E&T Magazine. If you are an IET member, log in to your account and the discounts will automatically be applied.

Learn more about IET membership 

Recommend Title Publication to library

You must fill out fields marked with: *

Librarian details
Your details
Why are you recommending this title?
Select reason:
IET Generation, Transmission & Distribution — Recommend this title to your library

Thank you

Your recommendation has been sent to your librarian.

Loss of excitation (LOE) event threatens both the generator and power system stability. Numerous approaches have been proposed for LOE detection, most of which use the impedance trajectory. Such methods may maloperate under system disturbances, especially power swings. This study presents a new approach for LOE detection by estimating the field flux linkage participation (FFLP) in the stator flux linkage. Intrinsically, this newly defined index mainly depends on the generator excitation system and thus highly reduces when an LOE takes place. The FFLP parameter can easily be calculated using stator voltage and current signals. All kinds of LOE events cannot be studied using most available simulation software. To cover all of them, utilising state variables, a generator model connected to a power system is implemented. Performed simulation studies demonstrate that the proposed strategy not only considerably decreases the LOE relay operation time, but also improves the LOE relay security against system disturbances. In addition, the proposed approach is experimentally evaluated on a 10 kVA synchronous generator.


    1. 1)
      • 1. Yulan, Z., Yong, X.: ‘Operation statistics and analysis of relay protection and automatic devices of Chinese power systems in 1995’, Power Syst. Technol., 1996, 20, (12), pp. 5761.
    2. 2)
      • 2. IEEE Guide for AC Generator Protection, IEEE Std. C37.102, February 2006.
    3. 3)
    4. 4)
    5. 5)
      • 5. Reimert, D.: ‘Protective relaying for power generation systems’ (Taylor & Francis, Boca Raton, 2006, 3rd edn.).
    6. 6)
      • 6. Mason, C.R.: ‘New loss-of-excitation relay for synchronous generators’, AIEE Trans., 1949, 68, (2), pp. 12401245.
    7. 7)
    8. 8)
    9. 9)
    10. 10)
    11. 11)
    12. 12)
    13. 13)
      • 13. Tambay, S.R., Paithankar, Y.G.: ‘A new adaptive loss of excitation relay augmented by rate of change of reactance’. Proc. IEEE Power Engineering Society General Meeting, 2005, vol. 2, pp. 18311835.
    14. 14)
    15. 15)
    16. 16)
    17. 17)
    18. 18)
      • 18. Yaghobi, H.: ‘Impact of static synchronous compensator on flux-based synchronous generator loss of excitation protection’, IET Gener. Transm. Distrib., 2015, 9, (9), pp. 874883.
    19. 19)
    20. 20)
    21. 21)
    22. 22)
      • 22. Kundur, P.: ‘Power system stability and control’ (McGraw-Hill, New York, 1994).
    23. 23)
    24. 24)
    25. 25)
      • 25. Park, R.H.: ‘Two-reaction theory of synchronous machines–generalized methods of analysis’, AIEE Trans., 1929, 48, pp. 716727.
    26. 26)
      • 26. Zhang, K., Yin, X., Chen, D., et al: ‘Simulation analysis of dynamic performance for hydro-generator under loss of excitation condition’. UPEC, Proc. of the 41st Int., September 2006, pp. 540544.
    27. 27)
      • 27. Seetharaman, C.K., Verma, S.P., El-Serafi, A.M.: ‘Operation of synchronous generators in the asynchronous mode’, IEEE Trans. Power Appar. Syst., 1978, 3, pp. 928939.
    28. 28)
      • 28. Shiying, M., Minxiao, H., Chongru, L., et al: ‘IEEE 9 buses system simulation and modeling in PSCAD’. Power and Energy Engineering Conf. (APPEEC), Asia-Pacific, March 2010, pp. 14.
    29. 29)
      • 29. Power Plant and Transmission System Protection Coordination, NERC System Protection and Control Subcommittee, Rev. 1, Jul. 2010. Available at

Related content

This is a required field
Please enter a valid email address