Analysis of the Nigerian 330 kV Electric Power Network Using an Extended Heffron-Phillips Model Technique

Michael O. Omoigui(1*), Olorunfemi Ojo(2)

(1) Department of Electronic and Electrical Engineering, University of Nottingham, United Kingdom
(2) Tennessee Technological University, United States
(*) Corresponding author

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Research on the dynamics of electric power systems are generally focused on inter-connected systems and little attention has been given to understand the unique characteristics of longitudinal power systems which are very common in developing countries of the world especially in Africa and South America. This paper therefore investigates the dynamics of the longitudinal Nigerian power system with the use of an extended Heffron-Phillips Model technique to provide insights into possible small and large signal dynamic trends.  Based on the small signal analysis, the reduced model of the Nigerian power system provides a clear and practical basis for examination of the causes of small-disturbance instability phenomena. Investigation shows that critical eigenvalues which corresponds to oscillatory modes of 1.05 Hz, 1.14 Hz and 1.16 Hz for 80% load; 0.99 Hz, 1.40 Hz and 1.10 Hz for 90% load; and 0.93 Hz, 1.72 Hz and 1.025 Hz for 100% load; and 0.533 Hz, 2.38 Hz and 0.66 Hz for 110% load respectively. These are undamped natural oscillation frequencies corresponding to rotor angle modes of the machines in the network. They suggest the possible use of FACTS devices to stiffen longitudinal power systems to improve both the dynamic and transient stability of the system to which such systems are susceptible to.
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Modeling; Dynamic Stability; Power Balances; Longitudinal Network; Eigenvalues

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Dineley, J. L and Kennedy, M. W, “Concept of Synchronous Generator Stability”, Proc. IEE Vol. 111, No. 1, January 1964, pp 95 – 97

Heffron, W. G. and Phillips, R. A. “Effects of a Modern Voltage Regulator on Under-Excited Operation of Large Turbine Generators”, AIEE Trans. On Power Apparatus and Systems, PAS 71, August 1952, pp 692 – 697.

d.Mello F. P. and Concordia, C, “Concept of Synchronous Machine Stability as Affected by Excitation Control”, IEEE Trans on Power Apparatus and Systems, PAS 88, No. 4, April 1969, pp 316 – 329.

El-Sherbiny, M. K and El-Serafi, A. M, “Analysis of Dynamic Performance of Saturated Machine and Analog Simulation”, IEEE Trans on Power Apparatus and Systems, PAS 101, No. 7, July 1982, pp 1899 – 1906.

Anderson, P. M. and Fouad, A. A, Power System Control and Stability, 2nd Edition, 2003, IEEE Press Power Engineering Series, Piscataway, NJ.

Kundur, Prabha, Power System Stability and Control, The EPRI Power System Engineering Series, McGraw-Hill, Inc.1994.

Komolafe, O.A, Omoigui, M.O. and Momoh, A., “Reliability Investigation of the Nigerian Electric Power Authority Transmission Network in a Deregulated Environment”, Proceedings of the IEEE Industry Applications Conference, 12-16 Oct. 2003, vol. 2, pp. 1328 – 1331.

Bhatti, T. S. and Hill, D. J, “A Multi-machine Heffron-Phillips Model for Power Systems with Frequency- and Voltage- Dependent Loads”, Electrical Power & Energy Systems, Vol. 12, No 3, July 1990, pp 171 – 182.

Concordia, C and Ihara, S, “Load Representation in Power System Stability Studies”, IEEE Trans. On Power Apparatus and Systems Vol. PAS-101, No 4, 1982, pp 969 – 977.

Berg, C. J, “Power-System Load Representation”, Proc. IEEE Vol. 120, No3, 1973, pp344 – 348.

Fleming, R. J, Mohan, M. A and Parvatisam, K, “Selection of Parameters of Stabilizers in Multi-Machine Power Systems”, IEEE Trans. On Power Apparatus and Systems Vol. PAS-100, No 5, 1981, pp 2329 – 2333.

IEEE Committee Report, “Excitation System Models for Power System Stability Studies”, IEEE Trans. On Power Apparatus and Systems Vol. PAS-100, No 2, 1981, pp 494 – 509.

Milano Federico, Power System Analysis Toolbox (PSAT),, July 2005

Sauer, Peter W. and Pai, M. A, Power System Dynamics and Stability, Prentice Hall Inc. Upper Saddle River, New Jersey 07458, 1998.

W. S. Kao, “The Effect of Load Models on a Low-frequency Oscillation Incident in Taipower System Using Eigen-Value Analysis”, J. Technol., Vol.16, 2001, pp 391 - 400

David Momoh, “Analysis of Nigerian High Voltage Electricity Supply Network". M.Sc. Thesis, Obafemi Awolowo University, Ile-Ife, Nigeria, December 2004.

Michael O. Omoigui, Olusola A. Komolafe and Olorunfemi J. Ojo, “Reinforcing the Nigerian 330 kV Electric Power Network to Increase Power Delivery and Improve Steady-State and Transient Stability”, Ife Journal of Technology, Vol. 16 No 1, 2007, pp 87 - 98.


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