Optimal capacitor placement and sizing in non-radial distribution to improve power quality

In this paper, a modified particle swarm optimization (PSO) is presented to find the optimal capacitor placement in a non-radial distribution system. The idea for optimal capacitor placement is to determine the location and the size of capacitor to be installed in the distribution network buses. The objective function is to minimize the line losses in a distribution network. The feeders and transformers loading (allowed current) and the buses voltage are considered as constraints in the objective function. In this study power factory from Digsilent, which is one professional network analysis tool for investigations of distribution networks is used. A modified PSO algorithm has been coded in Digsilent Programming Language (DPL) to solve problem. We compare bus voltage profile and line loading before and after capacitor installation.