Coordination of overcurrent directional relays in meshed networks using the Simplex method

In this paper, the authors formulate the coordination problem of a set of directional overcurrent relays installed in meshed power networks. After analysing the topology of the network to identify the primary/back up pairs, the coordination problem is organized in terms of a linear programming problem to be solved using the Simplex method. As a result, this application gives the instantaneous relay settings, the relay pick up taps and the time dial settings. The methodology is illustrated using a small power network mainly conceived for didactic purposes