Abstract Voltage unbalance and voltage variations are common issues in low voltage distribution networks caused by unbalanced connection of single-phase loads and electric vehicles (EVs) among phases. Part of the real low voltage grid in Bosnia and Herzegovina, in the vicinity of the town of Tešanj, was analysed. The impact on single-phase consumer and single-phase EVs penetration was analysed. The grid was modelled using DIgSILENT PowerFactory software. Three cases of the distribution of consumers by phases were analysed. Each of the three cases is expanded with four scenarios depending on the penetration of EV into the grid. Results showed that none of the twelve scenarios remained within the permissible limits of −10% voltage variation limit of EN 50160 for phase A. Seven of the twelve scenarios exceeded voltage unbalance limits +2% according to EN 50160.

Abstract This paper investigates the strategic placement of capacitor banks in the distribution network of Gračanica, with a specific focus on the medium-voltage feeder Grades. The primary objective is to optimize voltage profiles, minimize power losses, and enhance the overall performance of the distribution network. The significance of this research lies in its thorough examination of optimal capacitor placement within the medium-voltage (MV) branch of distribution networks, specifically considering the intricate interplay between capacitor banks and MV branch components, underlining the necessity for informed decisions in the context of distributed generators (DG) integration to enhance overall network performance. The study further investigates the impact of integrating DGs on these objectives on capacitor placement in the MV feeder. Employing the DIgSILENT PowerFactory software tool for modelling the MV feeder and utilizing a genetic algorithm for capacitor placement optimization, the study underscores the robustness of this approach in handling various conditions and seeking optimal solutions. Simulation results demonstrate that strategically placing capacitor banks and integrating DGs can significantly improve the voltage profile and reduce power losses within the distribution system. The findings of this research support 2MVA of concentrated DGs at the middle of the line as the most efficient and most economically beneficial situation on the medium-voltage feeder Grades study case and contribute valuable insights, serving as a reference for future studies on optimal capacitor placement.

Distributed generation (DG) especially energy acquired from renewable energy sources (RES) plays a significant role in modern power sector due to high carbon emissions around the globe. Its emerging potential is feasible by implementing microgrids as they are beneficial for networks in terms of increasing flexibility and stability, providing frequency and voltage support, power factor compensation etc. This makes the investment into microgrid incorporating RESs attractive, while at the same time reducing overall investment in the grid. Higher cost and stochastic nature of intermittent RES are complications for the implementation and operation of such solutions. This paper will analyse economic feasibility of hybrid power system (HPS) implementation consisting of a wind generator (WG), a photovoltaic system (PVS), gas combined heat and power plant (CHP) and storage batteries. Each of the elements is optimized according to power demand and RES’s potential. Technical analysis of the grid integration, parallel operation of the system and the grid is analysed with an example of a real medium-voltage distribution network operating in Bosnia and Herzegovina by using quasi-dynamic load flow simulation of one-week time-period. Finally, different operating mechanisms and strategies will be proposed, following the minimal power form the grid premise to satisfy maximum usability of RES’s potential. It is shown that implementing such HPS would be beneficial in terms of both economy and, ecology, as well as in reducing energy losses. Besides, it will reduce power supplying costs and energy losses, as well as and secure better exploitation and utilization of natural renewable energy sources. These technologies positively affect power network by decreasing the risk of network-components overloading, better exploiting the power-generation facilities based on renewable resources and positively impacting voltage profiles. Similar places, situated on remote locations, may use this analysis as an example to follow, to reduce their costs of electricity, acquire more reliable and sustainable power supply, and embrace green future.

Abstract In the dynamic field of power systems, integrating distributed generation (DG) sources like solar photovoltaic (PV) plants is crucial for enhancing reliability and fostering sustainability. However, this integration poses voltage profile management challenges in electrical grids. This study investigates voltage profile optimization in Bosnia and Herzegovina’s Gračanica network, focusing on a medium voltage feeder with 68 buses. Using DIgSILENT PowerFactory software, six scenarios with different configurations of solar plants are analyzed for their impact on voltage profiles and power losses. Results show that while DG integration offers benefits, incorrect sizing or placement can increase power losses. Optimal DG benefits are linked to specific sizes and locations. This research emphasizes the need for balancing PV generation with load demands and provides insights for optimal PV plant size and output to minimize negative impacts. These findings aid energy planners and policymakers in implementing distributed solar PV in medium voltage networks.

Abstract Voltage unbalance is common issue encountered in low voltage distribution networks, caused by uneven allocation of single-phase customers among phases. This paper analyses part of real low voltage distribution network in Bosnia and Herzegovina. The impact of single-phase customers and single-phase connected micro photovoltaic power plants (MPPP-s) were analysed. To reduce unbalance and improve voltage profiles, Phase Balance Optimization toolbox in DIgSILENT PowerFactory software was performed in six scenarios with different distribution of customers and different percentage of penetration of MPPS-s. The aim was to find method with least number of changes in customer and photovoltaic phase connection that fits within defined limits of voltage variations and voltage unbalance of European standard for power quality (EN 50160). Conclusion is that MPPP-s cause voltage increases in the network, as well as an increase in voltage unbalance, but these effects can be mitigated by proper distribution of customer loads and MPPS-s among phases.

While distributed generators (DGs) can reduce carbon dioxide emissions, they can also cause disturbances and lead to power quality (PQ) issues, with harmonic voltages being an important parameter to consider. In this paper, the impact of 14 connected photovoltaics (PVs) and a small hydropower plant (sHPP) on harmonic voltage distortions in a real medium voltage (MV) and low voltage (LV) distribution network in Bosnia and Herzegovina was analyzed. Simulation tools carried out by DigSILENT PowerFactory offer a wide range of advantages that give system operators the ability to have insight into PQ behavior in the presence of intermittent renewable energy sources (RES). Due to the inverter-based electricity generation, PV power plants inject harmonics into the LV network. The impact is relatively small and does not violate the limits from the European PQ standard EN 50160 due to the relatively small power of the modelled existing PVs. However, integrating additional PVs could lead to a violation of limits. Therefore, where a large power of PV power plants is installed, if it is possible to integrate sHPP, they will contribute to the reduction of generated harmonics without the need to reduce the power of PV. The contribution of this paper is that it compares the impact of different power generation technologies on harmonic voltages using data from a real network rather than a test network.

Abstract In the past couple of years, the integration of electrical vehicles (EV) in the power system has been capturing the attention of many researchers, which has led to this being a frequently analysed topic in scientific papers and seminars. Some of the main parameters related to power quality that are observed, while integrating EVs, are voltage variations and voltage unbalance. The low-voltage rural network, of a small settlement located on the outskirts of Zavidovici, has been modelled for the purpose of this paper. Several cases were considered. As the first base case, an analysis was performed when there were no connected vehicles in the network, then the case with 20% penetration, 35% penetration, and 80% vehicle penetration. Practical analysis was done in DIgSILENT Power Factory software. It has been concluded that electrical vehicles cause a voltage drop in the network, while at the same time causing an increase in voltage unbalances.

Abstract Phase unbalance is a common issue encountered in LV electricity distribution networks, caused by uneven allocation of single-phase loads among phases. This paper analyses a part of a real LV distribution network, situated in Bosnia and Herzegovina. The impact of single-phase customers and single-phase charging of electric vehicles was analysed. To reduce unbalance and improve the voltage profiles, Phase Balance Optimization in DIgSILENT PowerFactory software was performed in six scenarios with different customer and electric vehicle unbalance. The goal was to find a method with the least number of changes in the customer and electric vehicle phase connection that fits within defined limits of voltage variations and voltage unbalance of a European norm for power quality (EN 50160). Results showed that all analysed scenarios were improved, with reference to voltage variation and voltage unbalance values, and were found acceptable by the limits from standard EN 50160.