In this study, a digital twin model of a hydroelectric power plant has been created. Models of the entire power plant have been created and malfunction situations of a sensor located after the inlet ...valve of the plant have been analyzed using a programmable logic controller (PLC). As a feature of the digital twin (DT), the error prediction and prevention function has been studied specifically for the pressure sensor. The accuracy and reliability of the data obtained from the sensor are compared with the data obtained from the DT model. The comparison results are evaluated and erroneous data are identified. In this way, it is determined whether the malfunction occurring in the system is a real malfunction or a malfunction caused by measurement or connection errors. In the case of sensor failure or measurement-related malfunction, this situation is determined through the digital twin-based control mechanism. In the case of actual failure, the system is stopped, but in the case of measurement or connection errors, since the data are calculated by the DT model, the value in the specified region is known and thus there is no need to stop the system. This prevents production loss in the hydroelectric power plant by ensuring the continuity of the system in case of errors.
Although distributed secondary control helps control microgrids, it can provide insufficient performance in some cases where the system includes both renewable energy sources (RESs) and energy ...storage systems (ESSs). Therefore, an improved distributed secondary control structure is proposed in this study to improve efficiency and reliability in island mode DC microgrids that include RESs and ESSs. In order to regulate the power flow in accordance with the real time generation of the sources, maximum power calculation algorithms have been created within the secondary control levels of the PV and wind controllers. Furthermore, a fuzzy logic‐based energy management system has been designed in the secondary control of the battery controller to manage the power flow of the whole system considering the battery charge states and the total power generated by RESs. The distributed secondary control operates in event‐triggered mode to reduce the communication burdens. To avoid zeno behavior, event‐triggered control is designed based on sampled data. The proposed control scheme has been tested in Simulink environment and its stability is verified using Lyapunov's stability criteria. Results show that the power demand is successfully provided proportionally among the RESs and the communication burden is reduced considerably.
An improved distributed control structure is proposed to improve efficiency and reliability in island mode DC microgrids. Maximum power calculation algorithms have been created within the secondary control levels of the PV and wind controllers and a fuzzy logic‐based energy management system has been designed in the secondary control of the battery controller to manage the power flow of the whole system.
This paper provides a comprehensive review of the future digitalization of microgrids to meet the increasing energy demand. It begins with an overview of the background of microgrids, including their ...components and configurations, control and management strategies, and optimization techniques. It then discusses the key digital technologies that can be used to improve the performance of microgrids, including distributed energy resources management systems, the Internet of Things, big data analytics, blockchain technology, artificial intelligence, digital twin technology, cloud computing, and augmented reality. The paper also highlights the importance of cybersecurity in microgrids, identifying the potential security vulnerabilities and threats to microgrid cybersecurity, as well as strategies for addressing these challenges. Finally, the paper discusses the barriers and challenges regarding the digitalization of microgrids, including technical complexity, high implementation costs, regulatory barriers, data privacy and security concerns, lack of standardization, interoperability issues, limited technical expertise, and integration with the main grid. Overall, this paper demonstrates the significant potential for digital technologies to transform the future of microgrids. By leveraging advanced technologies and implementing effective cybersecurity measures, microgrids can become more efficient, reliable, and resilient, enabling them to meet the growing demand for energy and contribute to a sustainable energy future.
In this paper, an event-triggered distributed secondary control, along with an energy management algorithm, was developed to ensure the voltage stability and power management of a DC microgrid ...containing batteries and renewable energy sources, such as PV systems and wind turbines. The energy management algorithm, employing fuzzy logic control, governs power flow based on the generation status of sources and the charging rate of the battery. Consequently, the control algorithm shields the battery from overcharging and over-discharging situations, simultaneously ensuring energy quality within the microgrid. Sampled-data-based event-triggered control is integrated into the proposed distributed secondary control to alleviate communication burdens between controllers, effectively avoiding Zeno behavior. To demonstrate the efficacy of the proposed control algorithm, several experimental studies were conducted on a real DC microgrid prototype. The results obtained confirmed the controller’s effectiveness. With the proposed control algorithm, autonomous control has been developed to ensure the safe and continuous operation of loads in island-mode microgrids, incorporating PV systems, wind turbines, and batteries, while also minimizing communication overhead. This control system adeptly manages power flow, safeguards the battery against overcharging and over-discharging, and optimizes the efficiency of intermittent energy sources.
This paper provides a comprehensive overview of organic photovoltaic (OPV) cells, including their materials, technologies, and performance. In this context, the historical evolution of PV cell ...technology is explored, and the classification of PV production technologies is presented, along with a comparative analysis of first, second, and third-generation solar cells. A classification and comparison of PV cells based on materials used is also provided. The working principles and device structures of OPV cells are examined, and a brief comparison between device structures is made, highlighting their advantages, disadvantages, and key features. The various parts of OPV cells are discussed, and their performance, efficiency, and electrical characteristics are reviewed. A detailed SWOT analysis is conducted, identifying promising strengths and opportunities, as well as challenges and threats to the technology. The paper indicates that OPV cells have the potential to revolutionize the solar energy industry due to their low production costs, and ability to produce thin, flexible solar cells. However, challenges such as lower efficiency, durability, and technological limitations still exist. Despite these challenges, the tunability and versatility of organic materials offer promise for future success. The paper concludes by suggesting that future research should focus on addressing the identified challenges and developing new materials and technologies that can further improve the performance and efficiency of OPV cells.
The paper analyzes the key features, performance, efficiency, and electrical characteristics of organic PV cells to highlight the latest trends and advancements by using comparative tables and a comprehensive SWOT analysis.
Summary
The power system inertia based on the kinetic energy stored in synchronously connected rotating machines has a crucial effect on the frequency stability. As long as the use of renewables is ...increased, the share of conventional generators in electrical energy generation is decreased. Thus, the existing rotational inertia in the power system is reducing day by day. Therefore, planning the daily generation schedule according to a realistic inertia estimation has become a vital requirement for modern power systems. In this context, this article deals with the change and the effect of the inertia in a power system under different seasonal conditions. Firstly, the inertia constant of Turkish transmission grid is estimated hourly from January to October 2019 by using real system data in order to reveal how the inertia changes under different generation plans. For this purpose, the aggregated model approach in which a total inertia constant is estimated for whole power grid by using inertia constant of each generation unit and the actual generated power of resources is used. Then, six major system disturbances occurred in 2019 are analyzed by utilizing real frequency data measured by phasor measurement unit (PMU) devices. Considering the share of renewable energy in the realized generation at the time of these disturbances, rate of change of frequency (RoCoF) analysis, and inertia calculations are made. As the main contributions, the article clearly illustrates how the inertia contributes to the frequency stability during system failures under different generation conditions. Furthermore, a realistic inertia study is presented, which has never been carried out for Turkish transmission grid. Moreover, real system data obtained from PMU devices during the real disturbances is used instead of using standard bus systems.
The power system inertia based on the kinetic energy stored in synchronously connected rotating machines has a crucial effect on the frequency stability. As long as the use of renewables is increased, the share of conventional generators in electrical energy generation is decreased. Thus, the existing rotational inertia in the power system is reducing day by day. This article deals with the change and the effect of the inertia in a power system under different seasonal conditions. Firstly, the inertia constant of Turkish transmission grid is estimated hourly from January to October 2019 by using real system data in order to reveal how the inertia changes under different generation plans. For this purpose, the aggregated model approach in which a total inertia constant is estimated for whole power grid by using inertia constant of each generation unit and the actual generated power of resources is used. Then, six major system disturbances occurred in 2019 are analyzed by utilizing real frequency data measured by phasor measurement unit (PMU) devices. Considering the share of renewable energy in the realized generation at the time of these disturbances, rate of change of frequency (RoCoF) analysis and inertia calculations are made.
The use of renewables can make it more challenging to maintain a balance between supply and demand in microgrids due to their variable generation profiles. To address this issue, microgrids can be ...designed to be grid-interactive or to include energy storage units, or both. Additionally, demand-side management (DSM) strategies can be implemented to facilitate control during peak periods. This paper presents a control system for a grid-interactive microgrid with photovoltaic (PV) panels and energy storage units. The proposed system uses a fuzzy-based algorithm to control the energy storage units and provides DSM through the use of a hybrid daily pricing model that combines multi-time rate and inclining block rate pricing methods. To optimize the global maximum power point of the PV panels under partial shading conditions, the microgrid model is tested with several metaheuristic optimization algorithms, including particle swarm optimization (PSO), gray wolf optimization (GWO), and dragonfly algorithm (DA). A hybrid algorithm that combines PSO and DA is also proposed. The resulting integrated control system includes both demand-side and grid-side control operations.
Supervisory control and data acquisition (SCADA) systems play an important role in electrical power systems, which is one of the most critical infrastructures. They usually include digital ...controllers like PLCs to realize the automation of electromechanical processes and to accomplish the real time services. Ensuring a secure communication between these field devices and the command center is vital from the security point of view. Because the most vulnerable part of SCADA systems is their communication protocols, this work focuses on the weaknesses of SCADA systems against the internal cyber-attacks such as Denial of Service (DoS), Man-in-the-Middle (MITM) and Replay. For this aim, a sample SCADA testbed environment has been designed at first and then the attacks mentioned above are tested on it. Experimental results show that although SCADA systems accomplish some mission critical tasks, the protocols used in their communication systems still lack of crucial security measures. Therefore, some immediate precautions to mitigate the vulnerabilities are suggested at the end of study.
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