As with any work of research, there is always more that can be done.
Aside from further testing of the code and the algorithms as they stand, there are several extensions and modifications which can be explored.
These include:
• expand network modeling
• remove limitations on formulation
• explore possibilities for improved contingency analysis
• implement for industry use
Though the modeling presented in this dissertation is quite general, there are certainly improvements that can be made. As monitoring devices become cheaper, more detailed information will become available on the behavior of the components of a distribution system. In particular, with more data it may be possible to use more accurate load models which are not combinations of constant power, constant current, and constant imped-ance. The inclusion of core loss in the transformer models is also important for some applications, but was not included in this formulation due to a lack of verifiable data. The automatic tap changes of voltage regulators might also be considered.
Further extensions to the formulation of PAWMS could be explored as well. In particular, it may be possible to extend the current formulation to
remove the limitations discussed in Section 7.2.1, making it possible to handle systems with a mixture of grounded and ungrounded sections.
One common use of a power flow algorithm is to study various possi-ble contingencies to determine the most profitapossi-ble configuration for the operation of the network. In such an application, the contingencies are typ-ically specified with respect to some base case. If the power flow solution for the base case is known, it may not be necessary to run a complete power flow for each contingency. It is possible that the concepts behind the pro-posed algorithms could be applied to compute partial or approximate power flow solutions for the contingencies, given the base case solution.
The exploration of this possibility might yield more efficient approaches to contingency analysis in distribution systems.
One of the most obvious ways of building upon the work presented in this dissertation is to convert the MATLAB® program, used for the study of the algorithms, to a compiled C or C++ program suitable for everyday use in by a power engineer in industry. Such a program could be a very useful tool for many applications in distribution planning and operation.
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[1] J. Arrillaga and C. P. Arnold, Computer Analysis of Power Systems, John Wiley & Sons, 1990.
[2] J. Arrillaga, C. P. Arnold, and B. J. Harker, Computer Modelling of Electrical Power Systems, John Wiley & Sons, 1983.
[3] M. E. Baran and F. F. Wu, “Optimal Sizing of Capacitors Placed on a Radial Distribution System”, IEEE Transactions on Power Delivery, Vol. 4, No. 1, January 1989, pp. 735-742.
[4] R. Berg, Jr., E. S. Hawkins, and W. W. Pleines, “Mechanized Calculation of Unbalanced Load Flow on Radial Distribution Circuits”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-86, No. 4, April 1967, pp. 415-421.
[5] A. R. Bergen, Power Systems Analysis, Prentice-Hall, Englewood Cliffs, NJ, 1986.
[6] H. E. Brown, G. K. Carter, H. H. Happ, C. E. Person, “Power Flow Solution by Impedance Matrix Iterative Method”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-82, April 1963, pp. 1-10.
[7] H. E. Brown, G. K. Carter, H. H. Happ, C. E. Person, “Z-Matrix Algorithms in Load-Flow Programs”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-87, No. 3, March 1968, pp. 807-814.
[8] M. S. Chen and W. E. Dillon, “Power System Modeling”, Proceedings of the IEEE, Vol. 62, No. 7, July 1974, pp. 901-915.
[9] T. H. Chen, M. S. Chen, K. J. Hwang, P. Kotas, and E. Chebli,
“Distribution System Power Flow Analysis - A Rigid Approach”, IEEE Transactions on Power Delivery, Vol. 6, No. 3, July 1991, pp. 1146-1152.
[10] T. H. Chen, “Generalized Distribution Analysis System”, Ph.D.
Dissertation, The University of Texas at Arlington, May 1990.
[11] C. S. Cheng and D. Shirmohammadi, “A Three-Phase Power Flow Method for Real-Time Distribution System Analysis”, IEEE/PES 1994 Summer Meeting, San Francisco, CA, July 1994, 94 SM 603-1 PWRS.
[12] H. D. Chiang, “A Decoupled Load Flow Method for Distribution Power Networks: Algorithms, Analysis and Convergence Study”, Electrical Power & Energy Systems, Vol. 13, No. 3, June 1991, pp. 130-138.
[13] H. D. Chiang and M. E. Baran, “On the Existence and Uniqueness of Load Flow Solution for Radial Distribution Power Networks”, IEEE Transactions on Circuits and Systems, Vol. 37, No. 3, March 1990, pp. 410-416.
[14] R. S. Dembo, S. C. Eisenstat, and T. Steihaug, “Inexact Newton Methods”, SIAM Journal on Numerical Analysis, Vol. 19, No. 2, April 1982, pp. 400-408.
[15] G. H. Golub and C. F. Van Loan, Matrix Computations, The Johns Hopkins University Press, Baltimore, MD, 1989.
[16] S. Iwamoto and Y. Tamura, “A Load Flow Calculation Method for Ill-Conditioned Power Systems”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-100, No. 4, April 1981, pp. 1736-1743.
[17] W. H. Kersting and D. L. Mendive, “An Application of Ladder Network Theory to the Solution of Three-Phase Radial Load-Flow Problems”, IEEE/PES 1976 Winter Meeting, New York, NY, January 1976, A 76 044-8.
[18] W. H. Kersting and W. H. Phillips, “A Radial Three-phase Power Flow Program for the PC”, Conference paper, presented at 1987 Frontiers Power Conference, Stillwater, OK, October 1987.
[19] G.X. Luo and A. Semlyen, “Efficient Load Flow for Large Weakly Meshed Networks”, IEEE Transactions on Power Systems, Vol. 5, No. 4, November 1990, pp. 1309-1316.
[20] D. Raji i , R. A kovski, R. Taleski, “Voltage Correction Power Flow”, IEEE/PES 1993 Summer Meeting, Vancouver, B.C., Canada, July 1993, 93 SM 570-2.
[21] D. Raji i and A. Bose, “A Modification to the Fast Decoupled Power Flow for Networks with High R/X Ratios”, IEEE Transactions on Power Systems, Vol. 3, No. 2, May 1988, pp. 743-746.
[22] R. Sedgewick, Algorithms, Addison-Wesley Publishing Company, Inc., 1983.
c˘ c´ c˘
c˘ c´
[23] D. Shirmohammadi, H. W. Hong, A. Semlyen, and G. X. Luo, “A Compensation-based Power Flow Method for Weakly Meshed Distribution and Transmission Networks”, IEEE Transactions on Power Systems, Vol. 3, No. 2, May 1988, pp. 753-762.
[24] G. W. Stagg and A. H. El-Abiad, Computer Methods in Power System Analysis, New York: McGraw Hill, 1968.
[25] B. Stott, “Review of Load-Flow Calculation Methods”, Proceedings of the IEEE, Vol. 62, No. 7, July 1974, pp. 916-929.
[26] B. Stott and O. Alsaç, “Fast Decoupled Load Flow”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-93, May/
June 1974, pp. 859-869.
[27] D. I. H. Sun, S. Abe, R. R. Shoults, M. S. Chen, P. Eichenberger, and D. Farris, “Calculation of Energy Losses in a Distribution System”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-99, No. 4, July/August 1980, pp. 1347-1356.
[28] W. F. Tinney and C. E. Hart, “Power Flow Solution by Newton’s Method”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-86, No. 11, November 1967, pp. 1449-1460.
[29] W. F. Tinney and J. W. Walker, “Direct Solutions of Sparse Network Equations by Optimally Ordered Triangular Factorization”, Proceedings of the IEEE, Vol. 55, No. 11, November 1967, pp. 1801-1809.
[30] W. F. Tinney, “Compensation Methods for Network Solutions by Optimally Ordered Triangular Factorization”, Proceedings of the PICA Conference, Boston, MA, May 24-26, 1971, pp. 123-127.
[31] S. C. Tripathy, G. D. Prasad, O. P. Malik, and G. S. Hope, “Load Flow Solutions for Ill-Conditioned Power Systems by a Newton-Like Method”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-101, No. 10, October 1982, pp. 3648-3657.
[32] R. D. Zimmerman and H. D. Chiang, “Fast Decoupled Power Flow for Unbalanced Radial Distribution Systems”, IEEE/PES 1995 Winter Meeting, New York, NY, January 1995, 95 WM 219-6 PWRS.