Science and Education Publishing American Journal of Electrical and Electronic Engineering 2328-7357 4 2 2016 3 11 Optimal Placement of D-STATCOMs into the Radial Distribution Networks in the Presence of Distributed Generations 40 48 EN Babak Safari Chabok Ahmad Ashouri Department of Electrical Engineering, Khodabandeh Branch, Islamic Azad University, Khodabandeh, Iran AJEEE2016421 10.12691/ajeee-4-2-1 2015 11 15 2016 1 10 2016 3 9 This paper proposes a combination of Discrete Imperialistic Competition and Nelder-Mead algorithms to solve D-STATCOMs placement optimization problem. It is assumed that optimal number, locations and sizes of D-STATCOMs are determined in radial distribution network while Distributed Generations are previously installed in it. Indeed, we focus on voltage control and concept of reactive power management in annual scheduling time interval. Objective function is defined in terms of network active power losses and voltage stability characteristic at different load levels by appropriate weighting factors. Voltage Stability Index (VSI) is applied to identify the weak buses in radial distribution network. To validate performance and effectiveness of proposed DICA-NM hybrid algorithm, simulation studies are applied on the 30-bus IEEE radial distribution test feeder. Finally, numerical results for some important network variables have been compared in three different case studies.