a novel reconfiguration mixed with distributed generation planning via considering voltage stability margin

in recent years, in iran and other countries the power systems are going to move toward creating a competition structure for selling and buying electrical energy. these changes and the numerous advantages of dgs have made more incentives to use these kinds of generators than before. therefore, it is necessary to study all aspects of dgs, such as size selection and optimal placement and impact of them on distribution system (ds) reconfiguration. so, the problem of optimum reconfiguration and optimal location of dgs (dgs planning) in ds is a task which must be solved in an optimal manner. this paper presents a novel approach for optimum reconfiguration and optimal location of dgs in distribution networks based on a hieratical two-stage optimization problem to improve power system voltage stability margin and reduce active power losses. hence, a toolbox has been developed to recognize loadability limit of distribution power systems based on lagrangian optimization method. finally, the simulations are carried out on 33, 69 bus ieee distribution systems and demonstrate the validity of the proposed method.