Optimal Directional Overcurrent Relay Settings Using Automated Interval Coordination Matrix Algorithm

Abstract

Protective relays on any power system network must always operate correctly with minimum operating time to clear a fault. Until now, manual computations and curve-fitting techniques are still being used to coordinate relays on complex electrical grids. To eliminate these methods, this paper provides a time-efficient algorithm that can determine the optimal directional overcurrent relay settings of any power system network by automating the formulation of its Interval Coordination Matrix. The algorithm was first tested by validating the optimal relay settings of the 3 cases of the IEEE 14 Bus System from a previous study. The proposed algorithm reduced the time of simulation by 77.399%. Then, the researchers were also able to acquire the optimal relay settings on all the 642 fault cases of the 46-Bus Sub-Transmission Network. The result of this study provides a proof of time-efficient algorithm that can replace the manual methods in evaluating the settings of protection relays.