OPTIMIZATION OF OVERCURRENT PROTECTION RELAY COORDINATION IN DISTRIBUTION NETWORKS USING THE DIFFERENTIAL EVOLUTION ALGORITHM

Abstract

Modern distribution networks are becoming increasingly complex, making overcurrent relay coordination a highly nonlinear optimization problem with stringent constraints. This paper proposes using Differential Evolution (DE) to solve the relay coordination problem and compares its performance against the Genetic Algorithm (GA). Two scenarios are considered—purely nonlinear and mixed-integer nonlinear—both of which capture the practical characteristics of distribution systems. Experiments are conducted on the standard IEEE 8-bus system and an actual 22 kV distribution feeder. The DE algorithm reduces the total operating time of primary relays by 12.9756 % and 61.2469 % for the two scenarios on the IEEE 8-bus system, respectively, while also achieving faster convergence. These findings underscore the promising potential of DE for relay coordination in distribution networks.