Optimal sitting and sizing of distributed generators based on a modified primal-dual interior point algorithm

With the enhanced awareness of energy-saving, emission-reduction and environmental protection, distributed generators (DGs) have been increasingly employed in modern power systems, especially in distribution systems. DG can not only reduce energy losses, delay the expansion of transmission systems and hence the investment, but also enhance the security and stability of the power system concerned, improve voltage quality, increase energy utilization and reduce pollution emission. However, these advantages can be fully explored if the sitting and sizing of DGs are properly optimized. Inappropriate sitting and sizing of DGs could even lead to the increase in network losses and the drop of voltage quality at some buses. Given this background, a sensitivity based approach is presented to identify the optimal sitting of DGs. On the other hand, the optimal sizing of DGs is determined by the Modified Primal-Dual Interior Point Algorithm (MPDIPA) with an objective of maintaining the voltage profile at the optimal level. IEEE 123-node test feeder is employed to verify the effectiveness of the proposed method. The results demonstrate that the proposed approach is able to search for the optimal solutions quickly. At the same time, the voltage profiles are obviously improved and the network loss is decreased dramatically.