A Robust and Flexible Approach for Distribution Expansion Planning in the Presence of Distributed Generations and the Uncertainties Associated with Demand, Energy Price and Renewable Resources

Distribution expansion planning is one of the most important issues in power system the main objective of which is to meet the demand at minimum operating costs. Due to the uncertain nature of renewable-based distributed generators (DGs) as well as uncertainties of the network, new approaches should be proposed to take into account these uncertainties. Indeed, more robust and flexible planning methods are needed in order to deal with the aforementioned uncertainties. Therefore, in this paper a scenario-based approach is proposed to model the uncertainties. Moreover, to consider the effect of the uncertainties in the model, appropriate indices consisting of maximum regret as robustness criterion and maximum adjustment cost as flexibility criterion are employed. The proposed model is a multi-objective optimization one that is solved using an improved version of non-dominated sorting harmony search algorithm. Furthermore, a fuzzy decision-making analysis tagged with planner criteria is applied in order to obtain the global optimal solution. To show the effectiveness of the proposed model, it is applied to a radial nine-node distribution system. The results indicate that the operating costs, in the presence of different types of DGs and uncertainties, are significantly affected by the proposed approach.