This paper analyzes the behavior of photovoltaic (PV) power plants in low-demand power systems, with a focus on the power system of Bosnia and Herzegovina. To achieve a realistic representation of operational conditions, meteorological data specific to the region were incorporated into the analysis using a custom Python application for data collection and visualization. Simulations were performed using the EMTP software package to evaluate system performance under normal and faulty conditions. The behavior of both distant and close PV power plants was analyzed across various scenarios, with special attention given to the effects of different types of short circuits, the most common failures in power systems. The findings provide insights into the dynamic response of PV power plants in low-demand scenarios, contributing to improved stability and fault management strategies.

In order to research the advantages of usage of photovoltaic plants in smart grids, an analysis focused on the impact of photovoltaic systems on the stability and reliability of electrical grids is conducted in this paper. The paper addresses the technical aspects of integrating photovoltaic systems, including their variable production and how it affects the changes in electricity supply and demand in a real distributed power grid. Innovative technologies, such as energy storage devices and advanced communication systems, are also considered, which enable better control and management of the grid. The integration of a photovoltaic plant into a 20 kV network with consumers in the household and industrial categories, as well as an electric vehicle charging station, is analyzed with varying loads. The results obtained highlight the contribution of PV plants to the grid stability, reliability, voltage conditions, and total active and reactive power losses.

With the increase in the need to maintain uninterrupted power supply, due to sensitive devices in modern industry, more and more attention is paid to the protection of distribution lines in atypical construction conditions. Taking into account that lightning strikes are a frequent and main cause of power interruptions, it is necessary to take into account all the factors that can affect the improvement of the performance of distribution lines. This paper introduces a novel approach by incorporating tower grounding resistance, height, type, surge arrester, and flashover models in conditions of high soil resistance without physical protection. The proposed modelling procedure is validated through simulations on the 35 kV line "Kotor - Lovćen" in Montenegro, characterized by inadequate protection and high soil resistance, using the EMTP software and adhering to IEEE 1410 - 2004 standards.

The resulting shift in load and generation profiles on the low voltage (LV) network poses new risks for distribution system operators (DSOs), including issues like congestion and power quality. To address these risks, two approaches are considered: traditional grid reinforcement or flexibility services. An emerging solution for harnessing flexibility is the development of local markets. This paper is focused on defining scenarios for testing the local market, considering different network conditions (load profiles, available capacity limits in the lines), different market clearing mechanisms, and bids. The LV network under study is a real Slovenian LV network in Luče, currently featuring 9 flexible households and one community battery, as part of the X-FLEX project (Horizon 2020, grant agreement n°863927). The second part involves testing these scenarios and conducting an analysis of the results, ensuring network constraints compliance through power flow simulation (using OpenDSS), and performing a technical analysis of the market design based on these results.

Energy production is one of the most crucial scientific, technological, economic, and political challenges in today's world. In response to the increasing demands of the European Union for reducing CO2 emissions and mitigating climate change, countries are obligated to align their national energy plans with clearly defined objectives, aiming for climate neutrality by 2050. This paper explores the location potential and optimal implementation of biomass power plants in Bosnia and Herzegovina. Biomass power plants, particularly those utilizing wood and plant biomass, are a promising solution for simultaneously reducing pollution, addressing unnecessary waste, and improving the energy efficiency of the systems where they are installed. The paper concludes that the potential of wood and plant biomass in Bosnia and Herzegovina remains underutilized. From an eco-perspective, the paper will also examine the reuse of large degraded areas in mines, where the fast-growing energy crops like Miscanthus could be planted.

The transition process from fossil fuels to environmentally friendly renewable energy sources carries the risk of creating new environmental damages. Photovoltaic technology represents one of the alternatives with the least risk of harmful environmental impact. However, this technology has two important drawbacks: the significant land occupation for the installation of PV systems and the uncontrollability of production. By constructing floating photovoltaic plants on hydroelectric reservoirs, both of these problems can be reduced to an acceptable level. Some artificial reservoirs, originally built for hydroelectric power plants, have acquired a significant secondary function as recreational areas and fish breeding sites. Therefore, there is justified resistance from the local community to change the existing appearance and purpose of such reservoirs. This paper proposes a completely new concept of integrating the interests of the local community into such objects. In addition to preserving existing uses, the concept also offers new features. This can make the entire system environmentally friendly and sustainable. This paper details the technology behind the construction of floating photovoltaic power plants on artificial reservoirs and emphasizes their various advantages. These benefits include the non-utilization of cultivable land, the ease of assembly and construction, integration into existing power grids, and the potential to address electricity storage issues. For instance, Buško Lake, covering an area of 55.8 km2, may host 2.93 km2 of installed floating photovoltaic (FPV) facilities, enabling a total installed capacity of 240 MW. With an average of 5.5 h of daily sunshine, this totals 2007 annual hours, equivalent to a 55 MW thermal power plant. An analysis showed that, with losses of 18.2%, the average annual production stands at 302 GWh, translating to an annual production value of 18 million € at 60 €/MWh. The integration of this production into an existing hydroelectric power plant featuring an artificial reservoir might boost its output by 91%. The available transmission line capacity of 237 MW is shared between the hydroelectric power plant (HPP) and FPV; hence during the FPV maximum power generation time, the HPP halts its production. HPP Orlovac operates a small number of hours annually at full capacity (1489 h); therefore in combination with the FPV, this number can be increased to 2852 h. This integration maintains the lake’s functions in tourism and fishing while expanding its capabilities without environmental harm.

Recognizing the increasing importance of renewable energy sources, specifically wind farms, in today's power environments, this paper aims to clarify the complex interactions between these renewable energy facilities and distribution grids functioning under low-demand conditions. This particular case comes with inherent limitations that must be considered by taking into account all the factors that can influence the performance of the wind farm under these conditions. The modelling procedure and the simulation of the connection of the wind farm to the power system in rural area was performed using EMTP-RV software. The mean annual production of the wind power plant and the behaviour of the wind power plant in the event of failure in a real power system were calculated. Also, the power quality was examined in agreement with the Network Code of the transmission system of Bosnia and Herzegovina.

This research delves into the crucial role of solar energy, particularly photovoltaic (PV) conversion, in the global shift towards renewable sources. Focusing on the stochastic nature of PV power plants, the study emphasizes fault ride-through operations and their repercussions on electrical power systems. A detailed modeling approach is employed using Electromagnetic Transient Program (EMTP) software to simulate a large-scale PV power plant connected to a high-voltage transmission network. The analysis encompasses various fault scenarios, shedding light on the resilience of PV systems and their broader impacts during faults. This investigation enhances the understanding of PV dynamics in fault conditions, providing valuable insights for sustainable energy systems.

Nearby lightning strokes are often considered as a prime source of transient overvoltages in the substations. Lightning overvoltages can cause unreliable operation of power system and power supply interruptions. Calculation of expected lightning overvoltages is necessary to design appropriate protection system. This paper presents the analysis of the lightning overvoltage performance of real 400 kV overhead transmission line and gas insulated substation (GIS), considering various factors, such as lightning stroke locations, peak currents, front rise times, etc. EMTP-RV software was used to model transmission line and substation elements and conduct simulations, while transmission line lightning performance was determined using Sigma Slp software. The expected overvoltages and surge arrester currents are calculated and used to design lightning protection system of the considered substation. Obtained results also indicate the importance of proper modelling of power system elements and lightning strokes.

The contribution of renewable energy sources to the power system stability will have to be greater in the future. The problem will arise if the share of wind power plants in total production increases and large failures occur. Then, wind farms, which are often called inertia-less sources in the literature, will have to help maintain the frequency in a normal amount by changing the management method and based on fast PMU measurements. This can be done by using the synthetic inertia size, which is defined for sources that are derived from the system via energy converters and which do not participate in defining the total inertia of the system. This paper provides a better insight into the understanding of the concept of synthetic inertia, as well as insight into the current development of management and the application of synthetic inertia in maintaining the stability of the power system.

The increase in the number of wind farms and their share in the total electrical energy generation leads to the need for a different approach to this source in cases where the stability of the power system is potentially impaired. With the development of different types of wind power plants, equipped with power electronics devices, there is the possibility of quick power management and injection, in conditions when it is needed, where a huge amount of accumulated kinetic energy can also be used. This paper presents the influence of a wind power plant equipped with a full-scale converter on the transient stability in cases of close and distant short circuits, during the outage of a heavily loaded line. Special attention was paid to the Rate of Change of Frequency (RoCoF) in the power system in cases with and without a wind farm where fast power injections were possible.

Lightning parameters are needed in different engineering applications. For the prediction of the severity of transient voltages in power systems, an accurate knowledge of the parameters of lightning currents is essential. All relevant standards and technical brochures recommend that lightning characteristics should be classified according to geographical regions instead of assuming that these characteristics are globally uniform. Many engineers and scientists suggest that better methods for lightning current measurements and analyses need to be developed. A system for direct lightning current measurements installed on Mount Lovćen is described in this paper. Observed data were analyzed, and statistical data on parameters that are of interest for engineering applications were obtained, as well as correlations between various lightning parameters. Furthermore, a novel approach for classifying and analyzing lightning data from direct measurements based on empirical mode decomposition (EMD) is proposed. Matlab was used as a tool for signal processing and statistical analysis. The methodology implemented in this work opens possibilities for automated analysis of large data sets and expressing lightning parameters in probabilistic terms from the data measured on site.

The method of power transformer neutral point grounding is very important for power distribution network operation because it strongly affect the shapes and values of overvoltages and fault currents. Many methods of grounding are used in medium voltage (MV) power distribution networks. The selection of grounding method largely depends on the characteristics of power network connected to the substation. It is also necessary to consider the advantages and disadvantages of various neutral grounding methods during selection process to find the best solution from a technical and economical point of view. The effects of grounding methods on the characteristics of single-phase short circuit fault are discussed in this paper on the example of 110/20 kV substation ′′Bugojno′′. Modeling and simulation of the considered substation, power transmission and distribution lines are implemented in EMTP-RV software.

Short circuit faults are one of the most common disturbances in power systems that occur because of insulation failure due to a sudden overvoltage condition caused by lightning, switching operations, insulation contamination, etc. Medium voltage power distribution networks use different methods for grounding the neutral point. Influences of these grounding methods on the characteristics of single-phase short circuit fault are discussed in this paper on the example of substation “Bugojno”. Modeling and simulation are implemented in EMTP-RV (Electromagnetic Transient Program-Restructured Version) software. Data recorded by protection system during normal operation and three-phase short circuit fault in the substation are analyzed and used for comparison with simulation results to validate developed model of the observed part of power system. This validated model was then used to analyze the effects of neutral point grounding methods on the characteristics of single-phase short circuit fault.