Distributed generation (DG) based on renewable sources becomes more and more implemented in distribution networks. Some of these sources have non constant (wind power plants, photovoltaic planes) and some have a constant power production (biogas plants). Also, loads on a feeder change during the day. There is a need for different optimizations because a number of variable changes over time. The total daily active energy losses, daily financial profit, and total daily active energy production of DG are considered for optimization in the paper. The load changes are considered on day level and for each load separately (not on the feeder level, but on node level). The multiobjective approach is applied in the paper for optimizing. The evolutionary strategy is utilized as the optimization method. The two and three objective optimization problems are presented and solved in the paper. The IEEE 13 node unbalanced distribution test feeder is used for presentation of multiobjective optimization. The proposed procedure is performed using OpenDSS and MATLAB software.

The topic of research in this paper is the determination of losses on a radial distribution feeder at a certain moment based on measurements of input complex power in the feeder and voltages in the farthest network node and power flow calculation. The presented method of DE used to find a virtual load of each node is based on the defined objective function. The value of the objective function using DE algorithm is obtained by calculation of power flow. The virtual load thus obtained is then used in the calculation of power flows on the basis of which total losses in a network are determined. The proposed method attempts to overcome the problems arising from the uncertainty of node loads in the network at some point in the evaluation of network losses. Evaluation of the proposed method was carried out by performing tests on the IEEE 123 node test feeder

Simulating the static and dynamic behaviour of grounding systems using numerical methods is a well-established procedure. In order to achieve greater model accuracy, a special attention is usually paid to the construction of more complex models. Howe...