Optimization of directional overcurrent relay times by particle swarm optimization

An important problem in electrical engineering is to determine the optimal directional overcurrent relay times. The problem is modeled as a constrained nonlinear optimization problem in which the decision variables are the devices that control the act of isolation of faulty lines from the system without disturbing the healthy lines. Two models are considered namely IEEE-3 bus system and IEEE-4 bus system. The problem is solved using different versions of particle swarm optimization (PSO). The results obtained by PSO are compared with the results available in the literature. It is shown that PSO is able to provide superior results in terms of optimality and reliability in comparison to other methods.