Reducing the scenarios of network topology changes for adaptive coordination of overcurrent relays using hybrid GA-LP

In this study, using the concept of setting groups (SGs), an adaptive protection scheme is proposed to increase the reliability of the system. Connection and disconnection of switches and distributed generators result in various scenarios for network topology changes. A hybrid genetic algorithm (GA) and linear programming (LP) method is utilised to solve the problem, where the GA, in a near-optimal manner, classifies the scenarios of the network topology changes into a limited number of SGs and the LP algorithm optimally coordinates the overcurrent relays within the SGs. Simulations are performed on a radial distribution network and a meshed distribution network. Although by increasing the number of SGs the average operating time of the relays is decreased, the number of changes in the relay settings is increased. Therefore, the multi-objective optimisation algorithm is used to determine, the desired number of SGs. The results show the efficiency of the proposed adaptive protection scheme.