Optimal placement of the distribution substations to improve reliability under load growth

In this paper, an approach is proposed for planning distribution networks in which the placement of distribution transformer is optimally planned. The size, number, and placement of distribution transformers are optimally determined in order to improve system reliability and to minimize the losses under load growth. An objective function is constituted, composed of the investment cost, maintenance cost, loss cost, and reliability cost. The reliability worth is not usually considered in the optimization of the distribution substation placement. However, it may be effective on the planning problem. The proposed approach is applied to a test system consisting of 42 electric load points. It is observed that the considering reliability in the planning approach reduces the total cost of the distribution transformer placement. However, the associated investment cost is increased but the reliability cost is more decreased.