Definition of Bus Priority Vector to Solve Distribution Load Flow for Radial Networks using MATLAB

Subject Areas : Multimedia Processing, Communications Systems, Intelligent Systems

Peyman Nazarian ¹ ( Faculty of Electrical and Computer Engineering, Islamic Azad University, Zanjan Branch, Zanjan, Iran, )

Received: 2021-08-27 Accepted : 2021-09-23 Published : 2021-12-22

Keywords: SCADA, Radial Distribution Systems, MATLAB Software, online load flow analysis,

Abstract :

Introduction:  Load distribution analysis is a fundamental and basic study for all power networks, including distribution networks, which are used in steady-state conditions. Power system planning and operation, power network reorganization, and many optimization studies require a large number of load distribution calculations in normal and emergency situations. Due to the nonlinearity of the system of load distribution equations, it is necessary to use iterative solution methods to solve it. In addition, due to a large number of power grid buses, matrix algebra is used. Some of these applications require fast iterative solutions of load distribution and therefore it is very important that load distribution analysis is performed efficiently. A number of load distribution algorithms are specifically designed for distribution systems. One of these methods considers bus voltages as state variables and works based on an iterative algorithm and uses special methods to increase convergence.Method: The proposed algorithm of this paper called SDLF in this article does not need special matrices and complex programming. In this method, load distribution can be achieved easily with only a simple vector that shows the priority of buses, which we call BPV, and by using the forward-backward sweeper algorithm. It is worth mentioning that the BPV vector itself is extracted from the network topology. This work can be done both visually from the electrical diagram of the network and from the data matrix of network D by MATLAB software. Finding: In terms of the convergence of the solution, increasing the repetition has led to an increase in accuracy, and as a result, the 10th repetition has been chosen as a relatively accurate result to confirm the validity of the method, considering the required engineering precision. The obtained results show that even in the first iteration, an acceptable accuracy for the voltage range has been obtained. In steady state analysis of power networks, the voltage amplitude is more important than the voltage phase. The noteworthy point is that in calculating the voltage phase, it is not necessary to update its value in each step, and it is enough to calculate the voltage phase after obtaining the voltage ranges. Conclusion: In this article, a new method called SDLF is introduced to study the load distribution of distribution networks. The results of the implementation of the proposed method, with an acceptable engineering error, can be used in the common applications of power networks in the first iteration, and based on this, it can be used as an online load distribution in SCADA systems. The effectiveness of the method was checked on the test network of 33 IEEE buses in the text of the article and its validity was confirmed. The introduction of the BPV bus priority vector made it possible to avoid using complex matrices and additional calculations and to reduce the time of load distribution calculations.

References:

 

• [1] Augugliaro, L. Dusonchet, M. G. Ippolito, and E. R. Sanseverino, “An Efficient Iterative Method for Load-flow Solution in Radial Distribution Networks,” in Proc. IEEE Porto Power Tech Conf., Porto, Portugal, pp. 10 -13, 2001.


• [2] L. Baldwin and S. A. Lewis, “Distribution Load Flow Methods for Shipboard Power Systems,” IEEE Trans. Industry Applications, vol. 40, no. 5, pp. 1183-1190, Sep./Oct. 2004.


• [3] Aravindhababu, S. Ganapathy, and K. R. Nayar, “A novel technique for the analysis of radial distribution systems,” Elect. Power Energy Syst., vol. 23, no. 3, pp.167–71, 2001.


• [4] V. S. R. Murthy, M. R. Raju, G. G. Rao, and K. N. Rao, “Topology based approach for Efficient Load flow Solution of Radial Distribution Networks,” in Proc. 16th Nat. Pow. Sys. Conf., Heyderabad, A.P, India, pp. 176-179, 2010.


• [5] H. Teng, “A Direct Approach for Distribution System Load Flow Solutions,” IEEE Trans. on Power delivery, vol. 18, no. 3, pp.882-887, July 2003.


• [6] W. Stagg and A. H. El-Abiad, Computer Methods in Power System Analysis, New York, McGraw Hill, 1968.


• [7] T. Bhimarasetti and A. Kumar, “A New Contribution to Distribution Load Flow Analysis for Radial and Mesh Distribution Systems,” in Proc. IEEE Int. Conf. on Comput. Intel. and Commun. Net., Bhopal, India, pp. 14-16, 2014.


• [8] Shirmohammadi, H. W. Hong, A. Semlyen, and G. X. Luo, “A compensation-based power flow method for weakly meshed distribution and transmission networks,” IEEE Trans. Power Syst., vol. 3, no. 2, pp. 753–762, May 1988.


• [9] X. Luo and A. Semlyen, “Efficient load flow for large weakly meshed networks”, IEEE Trans. Power Syst., vol. 5, no. 4, pp. 1309–1316, Nov. 1990.


• [10] S. Cheng and D. Shirmohammadi, “A three phase power flow method for real time distribution system analysis,” IEEE Trans. Power Syst., vol. 10, no. 2, pp. 671-679, May 1995.


• [11] H. Haque, “Efficient load flow method flow distribution systems with radial or mesh configuration,” in Proc. IEE. Generat. Transm. Distrib., vol. 143, no. 1, pp. 33–38, 1996.


• [12] H. Haque, “A general load flow method for distribution systems”, Elect. Power Syst. Res., vol. 54, issue. 1, pp. 47–54, Apr. 2000.


• [13] Chang, S. Y. Chu, M. F. Hsu, C. S. Chuang and H. L. Wang, “An efficient power flow algorithm for weakly meshed distribution system” Elect. Power Syst. Res., vol. 84, issue. 1, pp. 90-99, Mar. 2012.


• [14] H. Teng, “A Direct Approach for Distribution System Load Flow Solutions”, IEEE Trans. on Power delivery, vol. 18, no. 3, pp. 882-887, July 2003.


• [15] M. Lin and J. H. Teng, “Phase-decoupled load flow method for radial and weakly-meshed distribution networks” in Proc. IEE. Generat. Transm. Distrib., vol. 143, no. 1, pp. 39–42, 1996.