Optimization of directional overcurrent relay times using Laplace Crossover Particle Swarm Optimization (LXPSO)

An important problem in electrical engineering is to determine the optimal directional overcurrent relay times. The problem is modeled as a constrained nonlinear continuous 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 optimization methodology is the Laplace Crossover Particle Swarm Optimization (LXPSO), which has recently been introduced by the authors. LXPSO uses a new information sharing strategy amongst the particles of the swarm using a new crossover, called Laplace Crossover (LX), based on Laplace distribution. The results obtained by LXPSO are compared with the results available in the literature. It is shown that LXPSO is able to provide superior results in terms of optimality and reliability in comparison to other methods.