Optimal reconfiguration and DG integration in distribution networks considering switching actions costs using tabu search algorithm

The penetration of distributed generation (DG) units has been steadily increasing in distribution networks (DNs). However, oversizing and improper locating or operating of them can increase the losses or deteriorate the voltage profile. In this regard, distribution network reconfiguration (DNR) can be envisioned as a solution to maximize the DG penetration while improving the voltage profile and minimizing the losses. So, a study on DNR with the presence of DGs is necessary, in which the switching action costs are taken into consideration, since they can impose an extra cost on the daily operations. This study proposes a solution to solve the siting, sizing, and operating of DGs and DNR problems simultaneously considering switching action costs, losses costs, and reactive power generation of DGs. To consider the reactive power limits, their capability curve (P–Q curve) is included in the model. DNR is a combinatorial optimization problem, while the entire problem is modeled as a mixed-integer nonlinear programming problem. To solve that, tabu search algorithm (TSA) as one of the most efficient global solver for combinatorial problems is used, and its results are validated by particle swarm optimization (PSO) algorithm. To enlighten the effectiveness of the proposed approach, 5 scenarios are defined on IEEE 33-bus and IEEE 69-bus test systems. The results are also compared to previous studies. It is shown that, thanks to embedding the reactive power generation and switching costs at the same time, maximum loss reductions can be realized, while the results are more realistic and reliable.