Optimal Allocation of DG Units in Radial Distribution Systems

In the current context of increasing electricity consumption and at the same time reducing CO2 emissions, distributed renewable energy sources have gradually become a new trend in distribution network development. Their widespread use can have a negative impact on the operation of the network. Arbitrary placement of these sources can cause both an increase in active power losses and a change in the voltage level in the nodes, with effects on the system’s stability. To address this issue, the paper uses the Grey Wolf Optimizer (GWO) algorithm to determine the optimal location and value of the DG that leads to minimal losses of active power, under the conditions of compliance with the restrictions regarding the voltage level in the nodes. The work takes into account DG that produces only active power (for example photovoltaic panels). IEEE 33-bus and IEEE 69-bus test distribution networks were used for the case study. The determinations were performed in MATLAB, by associating the GWO algorithm to calculating power losses in the analyzed network. The results demonstrate the importance of the optimal choice of both the DG location and their sizes for the efficient network operation. Through the optimal placement of the distributed energy source according to the results of the applied algorithm, the benefit of using a green energy source is accumulated with the reduction of active power losses and the improvement of the bus voltage level.