Online Maximum Loadability Monitoring Scheme for Smart Grid


This paper presents an algorithm based on Thevenin equivalent network for voltage stability evaluation. The proposed algorithm provides a technique for online predicting the largest possible margin to voltage collapse of an electrical power system. An online maximum loadability determination algorithm is developed by transforming the impedance margin, obtained from the Thevenin equivalent network, into the loading margin at each of the load buses in a power system. Furthermore, the proposed algorithm also takes system load trends into account for practical applications. The effectiveness of the proposed algorithm is tested on the IEEE 14 and 57 bus test systems. Simulation results have shown that the proposed algorithm is useful and practical for online voltage instability monitoring.

Share and Cite:

Su, H. , Chen, Y. and Lin, J. (2015) Online Maximum Loadability Monitoring Scheme for Smart Grid. Journal of Power and Energy Engineering, 3, 170-177. doi: 10.4236/jpee.2015.34024.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Schlueter, R.A. (1998) A Voltage Stability Security Assessment Method. IEEE Transactions on Power System, 13, 1423-1438.
[2] Kundur, P., et al. (2004) Definition and Classification of Power System Stability IEEE/CIGRE Joint Task Force on Stability Terms and Definitions. IEEE Transactions on Power System, 19, 1387-1401.
[3] Van Cutsem, T. and Vournas, C. (1998) Voltage Stability of Electric Power Systems. Kluwer, Norwell, MA.
[4] Kundur, P. (1994) Power System Stability and Control. McGraw-Hill, New York.
[5] Ajjarapu, V. and Christy, C. (1992) The Continuation Power Flow: A Tool for Steady State Voltage Stability Analysis. IEEE Transactions on Power System, 7, 416-423.
[6] Chiang, H.D., Flueck, A.J., Shah, K.S. and Balu, N. (1995) CPFLOW: A Practical Tool for Tracing Power System Steady-State Stationary Behavior due to Load and Generation Variations. IEEE Transactions on Power System, 10, 623-634.
[7] Vu, K., Begovic, M.M., Novosel, D. and Saha, M.M. (1999) Use of Local Measurements to Estimate Voltage-Stability Margin. IEEE Transactions on Power System, 14, 1029-1035.
[8] Verbic, G. and Gubina, F. (2004) A New Concept of Voltage-Collapse Protection Based on Local Phasors. IEEE Transactions on Power Delivery, 19, 576-581.
[9] Smon, I., Verbic, G. and Gubina, F. (2006) Local Vol-tage-Stability Index Using Tllegen’s Theorem. IEEE Transactions on Power System, 21, 1267-1275.
[10] Corsi, S. and Taranto, G.N. (2008) A Real-Time Voltage Instability Identification Algorithm Based on Local Phasor Measurements. Transactions on Power System, 23, 1271-1279.
[11] Dubrovin, B.A., Fomenko, A.T. and Novikov, S.P. (1984) Mod-ern Geometry—Methods and Applications. Springer- Verlag.
[12] Power Systems Test Case Archive, University of Washington College of Engineering. [Online]

Copyright © 2024 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.