This paper deals with reactive power compensation and harmonics elimination in medium-voltage industrial networks using a hybrid active power filter. It proposes a hybrid filter as a combination of a three-phase, two-level, voltage-source converter connected in parallel with the inductor of a shunt, single-tuned, passive filter. This topological structure greatly decreases the voltage and current stress over the elements of the active filter. We propose using a proportional-resonant current controller for driving the active part of the filter. Theoretical analyses and simulation results obtained from an actual industrial network model in PSCAD verify the viability and effectiveness of the proposed hybrid filter. In addition, the simulation results are validated by a comparison with the results obtained from a real-time digital simulator.
COBISS.SI-ID: 10780756
The combined economic-environmental dispatch problem is multidimensional, non-linear and highly constrained problem. A new model for multi-objective optimization of the combined economic-environmental power dispatch problem was developed, which focuses to cost and emissions criteria. A new computer code was developed based on improved genetic algorithm which is a powerful optimization method. It was tested on real systems. Results show that the optimal solution for real systems leads to decrease of quantity of undesired emissions to the environment and to decrease of generation costs.
COBISS.SI-ID: 25970727
In the paper, the use of electric vehicle public charging stations with energy storage system as a solution for voltage regulation in low-voltage grids with photovoltaics is introduced. A novel method is proposed to determine the energy storage system charging load, required for voltage regulation and compare the results for the different locations on the feeder. With time-series simulations, the energy size required for a station energy storage system is quantified. A Belgian low-voltage residential grid is used as a case study. The method and simulation results show the effectiveness of using public electric vehicle charging facilities with the additional function of voltage regulation in feeders with photovoltaics.
COBISS.SI-ID: 10091348
The calculation of flicker propagation is vital in assessing power quality levels throughout the network. As an alternative to the established stationary flicker propagation methods, this paper introduces representative voltage samples. The shorter 1-s voltage samples are extracted from the instantaneous voltages measured and can represent the longer operating periods of an arc furnace. Additionally, the flicker levels in nodes under the influence of flicker from multiple arc furnaces can be obtained without the use of superposition factors.
COBISS.SI-ID: 35976965
The paper deals with the influence of distributed generation (DG) on distribution line losses with respect to voltage profile. The article focuses on the development of a control strategy to minimize the grid losses and assure fairness regarding reactive power contributions. As retail customers typically have no choice where they are located along a feeder, it seems unfair that only some of them take all the burden and responsibility for the voltage rise. On the basis of new technologies in distribution networks, a new control system has been proposed that combines classical centralized and local control. Different control solutions were evaluated by means of computer simulations.
COBISS.SI-ID: 9420884