Impacts of Distributed Generators on the Oscillatory Stability of Interconnected Power Systems

Integration of distributed generation is continually and gradually affecting the stability of interconnected power systems. In this paper, the impacts of distributed synchronous generators on oscillatory stability are studied. In various parameter sub-spaces of interest, feasibility regions can be calculated to determine the conditions to sustain the stable operation of an interconnected power system. Through computations of the feasibility boundaries corresponding to Hopf bifurcations of electromechanical oscillatory modes, we determine the operating limits for a stable operation of the system under small and continual disturbances such as predictable changes in loading conditions of generators. Thus, with the case studies given in the paper, under different operating conditions, we investigate the effects of distributed synchronous generators on the oscillatory small-signal stability. It has been shown that penetrations of these generators can cause local or inter-area oscillatory instabilities depending on the system's topology, operating point and control parameters.

Anahtar Kelimeler:

Oscillatory stability, distributed generation, Hopf bifurcation, feasibility boundaries

Impacts of Distributed Generators on the Oscillatory Stability of Interconnected Power Systems

Keywords:

Oscillatory stability, distributed generation, Hopf bifurcation, feasibility boundaries,

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M. Ilic, F. Galiana, L. Fink, Power Systems Restructuring, Kluwer Academic Publishers, 1998.
E. H. Abed, P. P. Varaiya, “Nonlinear oscillations in power systems”, Int. Journal of Electric Power and Energy Systems, Vol. 6, pp. 37-43, 1984.
N. Kopell, R. B. Washburn, “Chaotic motions in two degrees of freedom swing equations”, IEEE Trans. on Circuits and Systems, Vol CAS-29, No. 8, pp. 738-746, 1982.
V. Venkatasubramanian, H. Sch¨attler, J. Zaborszky, “Dynamics of large constrained nonlinear systems – a taxonomy theory”, Proceedings of the IEEE, Vol. 83, No. 112, pp. 1530-1561, 1995.
C. Ca˜nizares, Voltage Stability Assessment: Concepts, Practices and Tools, IEEE-PES Power Systems Stability Subcommittee Special Publication SP101PSS. M. K. Donnelly, J. E. Dagle, D. J. Trudnowski, G. J. Rogers, “Impacts of the distributed utility on transmission system stability”, IEEE Trans. on Power Systems, Vol. 11, No. 2, pp. 741-746, 1996.
R. T. Guttromson, “Modeling Distributed Energy Resource Dynamics on the Transmission System”, IEEE Trans. On Power Systems, Vo. 17, No. 4, pp. 1148-1153, 2002.
J. G. Slootweg, W. L. Kling, “Impacts of distributed generation on power system transient stability”, Power Engineering Society Summer Meeting, Vol. 2, pp. 862-867, 2002.
T. Niknam, A. M. Ranjbar, A. R. Shirani, “Impact of distributed generation on volt/var control in distribution networks”, IEEE Bologna Power Tech Conference, 2003.
M. Ilic, J. Zaborszky, Dynamics and Control of Large Electric Power Systems, John Wiley & Sons Inc., 2000.
V. Venkatasubramanian, H. Sch¨attler, J. Zaborszky, “Local bifurcations and feasibility regions in differential- algebraic systems”, IEEE Trans. on Automatic Control, Vol. 40, No. 12, pp. 1992-2013, 1995.
J. Guckenheimer, P. Holmes, Nonlinear Oscillations, Dynamical Systems and Bifucations of vector fields, Springer-Verlag, 1983.
˙I. Gen¸c, H. Sch¨attler, J. Zaborszky, “Hopf bifurcation related coherent oscillations between clusters in the bulk power system”, IEEE Bologna Power Tech Conference, 2003.
˙I. A. ¨Ozcan, H. Sch¨attler, “On the calculation of the feasibility boundary for differential-algebraic systems”, Proc. 38th IEEE Conference on Decision and Control, pp. 2580-2586, 1999.
P. Kundur, Power System Stability and Control, McGraw-Hill, Inc., 1994.
S. B. Yusof, G. J. Rogers, and R. T. H. Alden, “Slow coherency based network partitioning including load buses, IEEE Trans. on Power Systems”, Vol. 8, No. 3, pp. 1375-1382, 1993.
˙I. Gen¸c, J. Zaborszky, Clustering the Bulk Power System for the Study of Oscillations, Thrid IFAC WS Automatic Systems for Building the Infrastructures in Developing Countries, pp. 189-194, 2003.