Modified shuffled frog leaping algorithm for optimal switch placement in distribution automation system using a multi-objective fuzzy approach

One of the main issues in distribution sector is to achieve simultaneously high system reliability and low capital costs. Distribution automation systems (DASs) involve automatic and remote-controlled switches. The switches play a significant role in system reliability improvement. This paper proposes the modified shuffled frog leaping algorithm (SFLA) to derive the optimal placement of manual and automatic switches in DASs. A fuzzy approach is used to handle the multi objective considerations, and a fuzzy membership function is defined for each term in the objective function. The first objective is reliability improvement by minimising the customer interruption cost (CIC), and the second objective is to minimise switches purchasing and maintenance cost (SPMC). In this paper, a new method is developed to evaluate CIC and SPMC indices in a distribution network. In the proposed method, customer types, customers load patterns, monthly, daily and hourly customers loading rates are considered. In addition, network branches´ failure rate, restoration time and repair time are taken into account. The performance of the proposed approach is assessed and illustrated by studying on the IEEE 123-node feeder standard test system. The simulation results verify the capability of the proposed method.