A PARALLEL-PROCESSING ALGORITHM FOR COORDINATION OF DIRECTIONAL OVERCURRENT RELAYS IN INTERCONNECTED POWER-SYSTEMS

The problem of co-ordinating the setting of directional overcurrent re lays in an interconnected power system is considered. The power system is decomposed into subsystems to give a constraint matrix of a diagon al structure with linking variables. Each subsystem is solved using th e sparse dual revised simplex algorithm of linear programming. Benders algorithm for linear programming may be used to co-ordinate the solut ion from each subsystem and the master system. The authors propose a n ew parallel processing algorithm for this co-ordination procedure whic h depends on the interaction balance principle of linear programming. This algorithm has been applied to various size systems and the result s compared with those obtained using a conventional linear programming algorithm and Benders algorithm. It is shown that the proposed algori thm is more computationally efficient than previous methods.