A parallel processing algorithm for co-ordination of directional overcurrent relays in interconnected power systems

The problem of coordinating the setting of directional overcurrent relays in an interconnected power system is considered. The power system is decomposed into subsystems to give a constraint matrix of a diagonal structure with linking variables. Each subsystem is solved using the sparse dual revised simplex algorithm of linear programming. Benders algorithm for linear programming may be used to coordinate the solution from each subsystem and the master system. The authors propose a new parallel processing algorithm for this coordination procedure which depends on the interaction balance principle of linear programming. This algorithm has been applied to various size systems and the results compared with those obtained using a conventional linear programming algorithm and Benders algorithm. It is shown that the proposed algorithm is more computationally efficient than previous methods