# 8-Bus System (System I)

I. Introduction:

$$\bullet$$ The network of this test case is shown in the figure given below, where the near-end $$3\phi$$ fault is considered. Bus 4 is connected to an external grid that is modeled by 400 MVA short-circuit capacity.
$$\bullet$$ Some studies named this system as a 6-bus test system, because bus 7 and bus 8 are connected to the generating units and do not have any relay.
$$\bullet$$ The available set of the discretized plug-setting ($$PS$$) is $$\{0.5,0.6,0.8,1.0,1.5,2,2.5\}$$. Although this test case has small dimension, it has been noticed that it is very hard to get feasibly and optimal solution; please refer to our study given in the references section.
$$\bullet$$ The CT ratios ($$CTRs$$) and the $$3\phi$$ short-circuit current for each P/B pair of relays are given below (click on them for bigger size):

II. Single-Line Diagram:

$$\bullet$$ This single-line diagram was drawn by Ali R. Alroomi in Sept. 2013 and all the necessary data were coded in MATLAB m-files.

III. Files:

$$\bullet$$ System DATA (MATLAB, m-file Format) [Download]
$$\bullet$$ Results Tester (MATLAB, m-file Format) [Download]

IV. References (Some selected papers that use this system):

[1] A.S. Braga, and J.T. Saraiva, "Coordination of Overcurrent Directional Relays in Meshed Networks Using the Simplex Method," in Electrotechnical Conference, 1996. MELECON '96., 8th Mediterranean, vol. 3, pp. 1535-1538, May 1996.
[2] H.H. Zeineldin, E.F. El-Saadany, and M.A. Salama, "Optimal Coordination of Directional Overcurrent Relay Coordination," in 2005 IEEE Power Engineering Society General Meeting, vol. 2, pp. 1101-1106, Jun. 2005.
[3] H.H. Zeineldin, E.F. El-Saadany, and M.A. Salama, "Optimal Coordination of Overcurrent Relays Using a Modified Particle Swarm Optimization," Electric Power Systems Research, vol. 76, no. 11, pp. 988-995, 2006.
[4] H.H. Zeineldin, "Optimal Coordination of Microprocessor Based Directional Overcurrent Relays," in 2008 Canadian Conference on Electrical and Computer Engineering (CCECE 2008), pp. 289-294, May 2008.
[5] A. Noghabi, J. Sadeh, and H. Mashhadi, "Considering Different Network Topologies in Optimal Overcurrent Relay Coordination Using a Hybrid GA," IEEE Transactions on Power Delivery, vol. 24, no. 4, pp. 1857-1863, Oct. 2009.
[6] T. Amraee, "Coordination of Directional Overcurrent Relays Using Seeker Algorithm," IEEE Transactions on Power Delivery, vol. 27, no. 3, pp. 1415–1422, Jul. 2012.
[7] F. A. Albasri, A. R. Alroomi, and J. H. Talaq, "Optimal Coordination of Directional Overcurrent Relays Using Biogeography-Based Optimization Algorithms," IEEE Transactions on Power Delivery, vol. 30, no. 4, pp. 903–911, 2015.
[8] V.A. Papaspiliotopoulos, G.N. Korres, and N.G. Maratos, "A Novel Quadratically Constrained Quadratic Programming Method for Optimal Coordination of Directional Overcurrent Relays ," To be published in IEEE Transactions on Power Delivery, 2015.