A Modified Unbalanced Load flow solution using Branch Incidence Matrix

N. Visali*, M. Satish Kumar Reddy**, M Surendranatha Reddy***
* Professor, Department of Electrical and Electronics Engineering, JNTUACEP, Pulivendula, Andhra pradesh
**-***Assistant Professor, Department of Electrical and Electronics Engineering, Vaagdevi Institute of Technology and Science, Proddatur
Periodicity:January - March'2014
DOI : https://doi.org/10.26634/jee.7.3.2706

Abstract

Distribution system is the system which supplies electrical power from generating station to consumers. But the practical loads in the radial distribution systems are generally unbalanced in nature. For analysing the system condition and also to forecast the load, the study of power flows is essential. The presence of high R/X ratio of the distribution system poses a challenge to the convergence criteria of commercial load flows such as Newton Raphson Method, Gauss Seidel method and Fast Decoupled methods. For this type of systems, some changes have been incorporated in above methods so as to obtain better convergence which are named as modified Newton Raphson Method, modified Gauss Seidel Method and Forward/Backward Sweep Methods. The pre-assumption of flat node voltage is essential to carry out the load flow solution in all these methods. A new method has been proposed to determine the solution without any preassumptive flat node voltage and also the unbalanced system is modelled as a balanced system using symmetrical components. The solution is obtained by incorporating relationship between node currents and branch currents using a concept of Branch Incidence matrix and thereby eliminating the need for flat voltage profile. The proposed method has been presented in three sections. In First section 1 the formation of the branch incidence matrix by modelling of unbalanced Radial Distribution System comprising of transformers, switches, capacitors etc. using symmetrical components, In section 2 node voltages and power losses are calculated using branch incidence matrix and system parameters. Finally in section 3, the results obtained are compared with the existing methods. The proposed method is solved for three different unbalanced Radial Distribution Systems such as IEEE 13 node, 19 node and 25 node systems and the results are presented.

Keywords

Unbalanced Radial Distribution System, Incidence Matrix, Transmission Losses, Branch, Linear Recursive Equations. TCIM (Three -Phase Current Injection Method)

How to Cite this Article?

Visali, N., Reddy, M. S. K., and Reddy, M. S. (2014). A Modified Unbalanced Load Flow Solution Using Branch Incidence Matrix. i-manager’s Journal on Electrical Engineering , 7(3), 27-34. https://doi.org/10.26634/jee.7.3.2706

References

[1]. D. Das, D. P. Kothari, and A. Kalam, (1995). Simple and efficient method for load flow solution of radial distribution networks, Electrical Power and Energy Systems, 17(5):335-346.
[2]. S. Ghosh, D. Das, (1999). Method for load flow solution of radial distribution networks, IEE Proc. Generation, Transmission and Distribution, 146(6):641-648.
[3]. P. Aravindhababu, (2003). A new fast decoupled power flow method for distribution systems, Electric Power Components and Systems, 31(9):869-878.
[4]. R. D. Zimmerman and H. D. Chiang, (1995). Fast decoupled power flow for unbalanced radial distribution systems, IEEE-PES Winter Meeting, paper no. 95, New York.
[5]. S. K. Goswami and S. K. Basu, (1991). Direct solution of distribution systems, IEE Proc. C, 188(1):78-88.
[6]. D. Thukaram, H. M. Wijekoon Banda, and J. Jerome, (1999). A Ronodet three phase power flow algorithm for radial distribution systems, Electric Power System Research, 50(3):227-236.
[7]. W. M. Lin, Y. S. Su, H. C. Chin, and J. H. Teng, (1999). Three-Phase unbalanced distribution power flow solutions with minimum data preparation, IEEE Trans. on Power Systems, 14(3):1178-1183
[8] P. A. N. Garcia, J. L. R. Pereira, S. Carnerio, V. M. da Costa, and N. Martins, (2000). Three-Phase power flow calculations using the current injection method, IEEE Trans. on Power Systems, 15(2):508-514.
[9] P. A. N. Garcia, J. L. R. Pereira, and S. Carneiro, Jr., (2001). Voltage control devices models for distribution power flow analysis, IEEE Trans. Power Syst., 16(4):586-594
[10]. P. A. N. Garcia, J. L. R. Pereira, and S. Carneiro, Jr., (2004). Improvements in the representation of PV nodes on three-phase distribution power flow, IEEE Trans. Power Del., 19(2):894-896.
[11]. K. N. Mui and H. D. Chiang, (2000). Existence, uniqueness and monotonic properties of the feasible power flow solution for radial three phase distribution networks, IEEE Trans. Circuit and Syst., 47(10):1502-1514.
[12]. W. M. Lin and J. H. Teng, (2000). Three-Phase distribution networks fast decoupled power flow solutions, Electric Power and Energy Systems, 22(5):375-380
[13]. T. H. Chen, M. S. Chen, K. J. Hwang, P. Kotas, and E. A. Chebli, (1991). Distribution system power flow analysis-a rigid approach, IEEE Trans. on Power Delivery, 6(3):1146-1153
[14]. J. H. Teng, (2002). A Modified Gauss-seidel algorithm of three-phase power flow analysis in distribution network, Electrical Power and Energy Systems, 24(2):97-102.
[15]. J. H. Teng, (2000). A Network-Topology-based Three- Phase Load Power Flow for Distribution Systems, Proceedings of National Science Council ROC (A), 24(4):259-264.
[16]. L. L. Grgsby: (1999). Editor-in-Chief, The Electric Power Engineering Handbook, CRC Press , pages 6-53 to 6- 62.
[17]. W. H. Kersting,(2002) ( Distribution System Modeling and Analysis, CRC Press, chapter 9.
[18]. J. Nagarath and D. P. Kothari, (1998). Power system Engineering, New Delhi: Tata McGraw Hill Publications, 2nd edition.
[19]. D. Shirmohammadi and Carol S. Cheng, (1995). A Three phase power flow method for real time distribution system analysis, IEEE Trans. on Power System, 10(2):671-679.
[20]. IEEE Distribution System Analysis Subcommittee, (1991). Radial distribution test feeders, IEEE Trans. on Power Systems, 6(3):975- 985. Radial Distribution test feeders.
[21]. web:http://www.ewh.ieee.org/soc/pes/dsacom/ testfeeders.html.
[22]. R.M. Saloman Danaraj, S.F. Kodad and Tulsi Ram Das, “An efficient software to solve distribution power flow in complex mode ” Research report AEC/R&D/DPF1,Electrical depar tment, Aurora's Technological Research Institute, Hyderabad
[23]. M. Ahmadigorji, A. Abbaspour, A. Rajabi- Ghahnavieh, M. Fotuhi- Firuzabad, (2009). “Optimal DG Placement in Distribution systems using Cost/Worth Analysis”, World Academy of Science, Engineering and Technology 49, pp. 746-753.
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