Electrically meaningful power system test case diagrams (Texas A&M Electric Grid Test Cases)

These images show simple test system diagrams for three of the test power systems in the Texas A&M "Electric Grid Test Cases" collection (see https://electricgrids.engr.tamu.edu/ and A.B. Birchfield, T. Xu, K.M. Gegner, K.S. Shetye, T.J. Overbye, "Grid Structural Characteristics as Validation Criteria for Synthetic Networks," to appear IEEE Transactions Power Systems) The three networks visualized here are "Illinois 200-Bus System: ACTIVSg200", "SouthCarolina 500-Bus System: ACTIVSg500" and "Texas 2000-Bus System: ACTIVSg2k" These network diagrams were created by applying the techniques described in: P. Cuffe; A. Keane, "Visualizing the Electrical Structure of Power Systems," in IEEE Systems Journal, 2015 The "Power Transfer" distance was use to create each diagram (see ibid. Section II. 3) As such, the diagrams are electrically meaningful: loosely speaking, buses drawn in close proximity should be able to transact power with each other with ease. Buses have been labelled as space permits, starting with the highest voltage buses first.