Reduced-order model for computing frequency oscillation mode of power systems

Reduced-order model for computing frequency oscillation mode of power systems

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

Buy article PDF
(plus tax if applicable)
Buy Knowledge Pack
10 articles for £75.00
(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.

Frequency oscillations with very low oscillation frequencies were observed in several power systems. In frequency oscillations, the speeds of all generators change coherently and the frequencies in the system oscillate together. An equivalent model, which only preserves the governors, turbines, and an equivalent generator, is subsequently built. In the model, the inter-machine rotor-angle oscillation modes are eliminated and only the frequency oscillation mode is preserved. First, a simplified relationship between the total generator output power and frequency is adopted to obtain an original reduced-order model. With the model, an initial estimation of the eigenvalue corresponding to the frequency oscillation mode is obtained. The initial estimation is used to obtain a more accurate relationship between the total output power and frequency, and then an improved reduced-order model is built. With the model, a more accurate eigenvalue estimation can be obtained. Owing to the low order of the proposed model, the computational burden is greatly reduced compared to the direct analysis with fully modelled systems. The test results verify the validity of the proposed method.


    1. 1)
      • 1. Cebeci, M.E., Karaagac, U., Tor, O.B., et al: ‘The effects of hydro power plants’ governor settings on the stability of Turkish power system frequency’. 5th Int. Conf. on Electrical and Electronics Engineering (ELECO2007), Bursa, Turkey, 5–9 December 2007.
    2. 2)
      • 2. Arango, O.J., Sanchez, H.M., Wilson, D.H.: ‘Low frequency oscillations in the Colombian power system – identification and remedial actions’. CIGRE Session, Paris, France, 22–27 August 2010.
    3. 3)
      • 3. Pico, H.V., Mccalley, J.D., Angel, A., et al: ‘Analysis of very low frequency oscillations in hydro-dominant power systems using multi-unit modeling’, IEEE Trans. Power Syst., 2012, 27, (4), pp. 19061915.
    4. 4)
      • 4. He, J., Zhang, J., Li, M., et al: ‘An approach for analysis and control of governor stability in islanded HVDC sending system’, Proc. CSEE, 2013, 36, (16), pp. 137143, (in Chinese).
    5. 5)
      • 5. Liu, C., Zhang, J., Chen, Y., et al: ‘Mechanism analysis and simulation on ultra-low frequency oscillation of Yunnan power grid in asynchronous interconnection mode’, South. Power Syst. Technol., 2016, 10, (7), pp. 2934, (in Chinese).
    6. 6)
      • 6. Kundur, P., Paserba, J., Ajjarapu, V., et al: ‘Definition and classification of power system stability’, IEEE Trans. Power Syst., 2004, 19, (2), pp. 13871401.
    7. 7)
      • 7. Fang, W., Wei, P., Du, Z.: ‘Reduced-order method for computing critical eigenvalues in ultra large-scale power systems’, IET Gener. Transm. Distrib., 2010, 4, (7), pp. 836845.
    8. 8)
      • 8. Rimorov, D., Kamwa, I., Joos, G.: ‘Quasi-steady-state approach for analysis of frequency oscillations and damping controller design’, IEEE Trans. Power Syst., 2016, 31, (4), pp. 32123220.
    9. 9)
      • 9. Moeini, A., Kamwa, I.: ‘Analytical concepts for reactive power based primary frequency control in power systems’, IEEE Trans. Power Syst., 2016, 31, (6), pp. 42174230.
    10. 10)
      • 10. Chan, M.L., Dunlop, R.D., Schweppe, F.: ‘Dynamic equivalents for average system frequency behavior following major disturbances’, IEEE Trans. Power Appar. Syst., 1972, PAS-91, (4), pp. 16371642.
    11. 11)
      • 11. Pai, M.A.: ‘Energy function analysis for power system stability’ (Kluwer, Boston, MA, 1989).
    12. 12)
      • 12. Kundur, P.: ‘Power system stability and control’ (McGraw-Hill, New York, 1994).
    13. 13)
      • 13. Ni, Y., Chen, S., Zhang, B.: ‘Theory and analysis of dynamic power systems’ (Tsinghua University Press, Beijing, 2002), (in Chinese).
    14. 14)
      • 14. IEEE Committee Report: ‘Transient stability test systems for direct stability methods’, IEEE Trans. Power Syst., 1992, 7, (1), pp. 3743.

Related content

This is a required field
Please enter a valid email address