Optimal Coordination of Directional Overcurrent Relays Using Enhanced L-SHADE Algorithm

Abstract

An optimization model based protection coordination method of directional overcurrent relays (DOCRs) in highly interconnected large size meshed power system network is a complex task due to its nature of highly constrained non-linear optimization problem. To overcome this complexity of DOCRs coordination, this paper proposes an optimal protection coordination of DOCRs considering optimal selection of standard time-current characteristic curves using enhanced linear population size reduction technique of success history based adaptive differential evolution (enhanced L-SHADE/eL-SHADE) algorithm which is an advanced version of differential evolution (DE) algorithm. The conventional L-SHADE algorithm is enhanced in three steps with a novel mutation strategy, incorporation of random local search by sequential quadratic programming and non-linear population size reduction scheme. Furthermore, an effectiveness of the proposed algorithm is validated by testing it on standard IEEE-30 bus and 57 bus meshed networks. A promising and highly competitive simulation results are obtained when compared with similar results presented in reference articles by other optimization algorithms. The evaluation criteria of the eL-SHADE algorithm is considered on the basis of objective function value, standard deviation, execution time and violation of constraints.