Highly Accurate Directional Overcurrent Coordination via Combination of Rosen's Gradient Projection-Complex Method with GA-PSO Algorithm

This research work involves a highly accurate directional overcurrent coordination using the complex method-Rosen's gradient projection nonlinear programming approach with the genetic algorithm-particle swarm optimization (GA-PSO) metaheuristic optimization algorithm. To accelerate the optimization process, manual tuning steps are proposed to remove miscoordinations quickly and to determine the relay type in the case that different relay curves are given for coordination. In this manner, the metaheuristic and the deterministic parts share their advantages so that their combination leads to a significant tradeoff between exploration and exploitation. In addition, different objective functions for each part are introduced. For various conditions, the proposed method is applied to the eight-bus transmission and 33-kV distribution part of the 30-bus IEEE power system. Next, the superiority of the proposed algorithm over other researches is verified by the observation that the results are in the range of dual setting schemes.