An Evolutionary Approach for Optimum Reconfiguration and Distributed Generation Planning Considering Variable Load Pattern Based on Voltage Security Margin

A novel method to solve the problem of reconfiguration and distributed generation (DG) planning in distribution systems is proposed in this paper. By a multistage hieratical optimization problem, this problem has been modeled as a nonlinear and multi-objective optimization problem based on to improve power system voltage stability margin, investment cost, and reduce losses. As the first stage, the ability of developed harmony search is used to reach the best network configuration and DGs location under variable load patterns. This reconfiguration algorithm starts with a radial topology by a theoretical approach based on the Graph concept and Matroid theory. The presented approach is useful to avoid tedious mesh checks for the topology constraint validation. In the second stage of proposed approach, the voltage stability index is calculated to evaluate static voltage stability security margin. This calculation is done for each time variable reconfiguration pattern with defined DGs planning based on a developed toolbox which evaluate the loadability limit and other terms of task function. Finally, the simulations are carried out on 69 and 119 bus IEEE distribution systems and have been compared with particle swarm optimization. The results show good enhancement to reach the optimum solution with respect to the other studies.