Power Electric Systems Research Articles

Intelligent System of Constructing Vector Diagrams of Electrical Circuits

Phasor diagrams are a powerful tool for visualizing and understanding the distribution of current, voltage, and power in electrical systems. During Russia's war against Ukraine, our energy industry has become very vulnerable to enemy attacks, and therefore needs a quick and effective recovery. Energy specialists lack software tools for working with the power system, and in the period of development of artificial intelligence, creating such tools is not so difficult. For example, familiar specialists often have to build vector diagrams - tools for visualizing and understanding the distribution of current, voltage and power in electrical systems. Using a combination of frameworks for working with artificial intelligence and creating a graphic shell, you can achieve the desired result in a few months, and at the same time do a useful thing for our victory. The YOLO model (based on the PyTorch framework) and the QT framework are considered among the proposed tools for creating an intelligent vector diagram construction system. The role of artificial intelligence is to recognize electrical elements in circuits and their connections to each other. Creating a user interface is an equally important thing, which is already implemented in many places with the help of QT. As of today, there is no specialized software tool for solving the problems of manual construction of vector diagrams, but the proposed approaches are already used for its creation. The system uses the Yolov5 model to recognize electrical elements on the circuit. The model is trained on more than 150 images and is able to recognize hand-drawn diagrams. Recognition is run as a separate process from the main program written in C++. This part of the system processes the input data from Yolo, saves it in a convenient format, creates a user interface, and displays the result as a vector diagram.

Analysis of energy storage operation and configuration in high percentage wind power electric system

Analysis of energy storage operation and configuration in high percentage wind power electric system

Comparative study of dynamic response by three types of energy storage systems for grid studies: A Microgrid Laboratory experimental-based study

Implementing Energy Storage Systems (ESS) is increasingly significant in power electrical systems. This is attributed to their ability to store surplus electricity generated by renewable energy sources such as wind and solar, contributing to the balance between generation and demand. Literature studies indicate that this practice enhances network stability and diminishes the need for expensive redesigns in infrastructure. This paper presents an exhaustive experimentation-based study of the dynamic response provided by three energy storage system technologies: supercapacitors, Lithium-Ion batteries, and Vanadium redox flow batteries, technologies with significant academic, research, and industrial interests nowadays. The objective of this research is the experimental evaluation of the performance of such technologies in real electrical system operations, focusing on determining the efficiency of charge and discharge, as well as the tracking of active and reactive power achieved through the associated grid interface. The experimental tests performed in a microgrid laboratory show these technologies’ advantages and limitations in different grid-integration applications, with the Lithium-Ion battery-based ESS demonstrating the highest efficiency and faster power response. The results achieved and reported in the article can serve as an essential input for researchers and technology developers to feed their models with more precise parameters and data that might provide results closer to the actual behaviour of the studied prototypes. The methodological framework used in this research is descriptive, experimental, and quantitative.

Performance Evaluation of Solar Photovoltaic Thermal Air Collector Based on Energy and Exergy Analysis

This work presents a comprehensive parametric study of thermal and electrical performance of four different designs of photovoltaic/ thermal air heaters (PV/T) based on energy and exergy analysis. The results are compared to that from the conventional design of flat duct PV/T. The main goal of these designs is to enhance the heat transfer inside the air duct and consequently to increase the system's electrical power output. A computer simulation program has been developed in order to calculate the electrical and thermal PV/T collector parameters. The results indicate that an increase of 52, 52.4, and 68.25 % in the total system efficiency has been achieved from the corrugated duct, double pass design and finned duct respectively. Furthermore, at a low mass flow rates the electrical efficiency has also been improved for the three types by 9.8, 14.6 and 12.6 % respectively compared to that of flat duct design. The temperature of the PV arrays has a major effect on the exergy efficiency and removing heat from the PV module keeps the net power output at satisfactory level.

Enhanced Adaptive Dynamic Surface Sliding Mode Control for Optimal Performance of Grid-Connected Photovoltaic Systems

This study presents an enhanced, adaptive, and dynamic surface sliding mode control (SMC), a cutting-edge method for improving grid-connected photovoltaic (PV) system performance. The suggested control approach uses dynamic SMC and adaptive approaches to enhance the robustness and efficiency of a system. Proportional–integral (PI) and SMC, two control systems for maximum power point tracking (MPPT) in PV systems, are compared in this paper. This study finds that the SMC system is a more effective and efficient MPPT approach for PV systems compared to the conventional PI control system. The SMC system’s unique feature is the capacity to stabilize grid voltage and attain a modulation index of less than one. An important component of power electronic system control is the index, which acts as a parameter representing the relationship between the output signal’s amplitude and the reference signal’s amplitude. The SMC method demonstrates improved robustness, efficiency, and stability, especially in dynamic operating settings with load and solar radiation changes. Compared to the PI control, the SMC exhibits a noteworthy 75% reduction in voltage fluctuations and an improvement in the power output of 5% to 10%. Regarding output power optimization, voltage stability, and accurate current tracking, the SMC system performs better than the PI control system. Furthermore, the SMC technique maintains a modulation index below one and guarantees grid voltage stability, both of which are essential for the efficiency and stability of power electrical systems.

Power Components Mean Values Determination Using New Ip-Iq Method for Transients

This paper deals with the quasi-instantaneous determination (in a single-step response time) of apparent, active, and reactive (i.e., blind and distortion) power mean values including the total power factor, total harmonic distortion, and phase shift of fundamentals of a power electronic and electrical system (PEES) using the ip-iq method, which is the main contribution of the paper. The power components’ mean values are investigated during the transient and steady states. The power components’ mean values can be determined directly from phase current and voltage quantities, using an integral calculus over one period within the next calculation step and using moving average and moving rms techniques (or digital filtering). Consequently, the power factor can be evaluated with known values of a phase shift of fundamentals (using a Fourier analysis). The results of this study show how a distortion power component during transients is generated even under a harmonic supply and linear resistive–inductive load. The paper contains a theoretical base, modeling, and simulation for the three and single phases of the transients in power electronic systems. The worked-out results can be used to determine and size any PES. The presented approach brings a detailed time waveform verified by simulations in Matlab/Simulink 2022a and the Real-time HW Simulator Plecs RT Box 1.

Multidomain Device-Level Fuel-Cell Modeling and Real-Time Hardware Emulation for Marine Research Vessel Power System

Marine research vessels (MRVs) are redesigned and refurbished to meet higher energy conversion efficiency and modular integration schemes while conforming to stronger environmental regulations. The proton exchange membrane fuel cell (PEMFC) is currently regarded as a potential power source for marine transportation applications due to its advantages of stability, sustainability, and zero emissions. This paper proposes a hierarchical scheme for the real-time hardware emulation of the MRV’s power system and a comprehensive multi-domain model for PEMFCs. The PEMFC model is presented in the electrochemical, hydration, and thermal domains by ordinary differential equations considering the interactions and dynamics of each domain. Meanwhile, the multi-domain PEMFC model considers the implications of the fluctuating supply of the onboard hydrogen circulation system. Moreover, the dynamics of the lithium-ion battery stacks are represented by an equivalent circuit model which considers heat flux phenomena. In the case study, the DC-AC grid of the MRV’s power system and electric propulsion system is configured using extensive electrification technology with an average model. The real-time hardware emulation is conducted on the Xilinx® UltraScale+™ VCU118 FPGA platform to execute the device-level and system-level behavior transients of the MRV. The results of the real-time hardware emulation have been validated against the full-scale hybrid MRV power system emulation over a wide operating range.

Addressing building related energy burden, air pollution, and carbon emissions of a low-income community in Southern California

This study examines the impact of low-income assistance and electrification programs on a disadvantaged community in Southern California. An urban building energy model is paired with an AC power flow and electric distribution system degradation model to evaluate how the cost of energy, carbon emissions, and pollutant emissions change after applying building weatherization, energy efficiency, and electrification measures to the community. Results show that traditional weatherization and energy efficiency measures (upgrading lighting and appliances, improving insulation to current building code standards) are the most cost-effective, reducing the cost of energy and carbon emissions by 10–20 % for the current community. Heat pump water heaters offer a 40 % average reduction in carbon emissions and almost 50 % decrease in criteria pollutant emissions, but at a cost increase of 17–22 %. Appliance electrification also reduces carbon emissions 5–10 % but increases cost by 7 % to 25 %. For reducing carbon, government programs that support building electrification are most cost-effective when they combine switching from natural gas to electricity with high efficiency system. Electrifying hot water and appliances effectively reduces emissions but must be paired with improved low-income assistance programs to prevent increased energy burden for low-income families. The urban building energy model and electrical distribution simulations used in this study can be replicated in other low-income communities.

Optimization of Topological Reconfiguration in Electric Power Systems Using Genetic Algorithm and Nonlinear Programming with Discontinuous Derivatives

This article addresses a comprehensive analysis of power electrical systems, employing a combined approach of genetic algorithms and mathematical optimization through nonlinear programming with discontinuous derivatives (DNLP) in GAMS. The primary objective is to minimize economic losses and associated costs faced by the network operator following disruptive events. The analysis is divided into two fundamental aspects. Firstly, it addresses the topological reconfiguration of the network, involving the addition of lines and distributed energy resources such as distributed generation. To determine the optimal topological reconfiguration, a genetic algorithm was developed and implemented. This approach aims to restore electrical service to the maximum load within the system. Secondly, an optimal energy dispatch was performed for each generator, considering the variation in load throughout the day. The system’s load curve is taken into account to determine the optimal energy distribution. Thus, the problem of economic losses is approached from two perspectives: the minimization of costs due to nonsupplied electrical energy and the determination of efficient energy dispatch for each generator after network reconfiguration. For the analysis and case studies, simulations were conducted on the IEEE 9- and 30-node test systems. The results demonstrate the effectiveness of the proposed solution, evaluated in terms of reduced load shedding and economic losses.

Structures, Submodule Topologies and Control Strategies for Modular Multilevel Converter

Global energy demand is rapidly increasing, and the limitations and disadvantages of traditional energy sources are becoming more evident. Traditional energy sources are finite, and their sustainability is facing significant challenges. Compared to traditional multi-level converters, modular multi-level converters (MMC) adopt a modular design that divides the entire converter system into several independent sub-modules, each responsible for converting specific voltage levels. This article provides an overview of the theoretical aspects, topology structures, basic operation principles, and output characteristics of multi-level converters. This paper reviews the characteristics and application ranges of different topology structures, highlighting the differences in response speed, output quality, and control complexity. This paper also discusses the advantages and limitations of multi-level converters in various application scenarios. Explored the application of multi-level converters in wind power grid integration and electric vehicle charging systems, emphasizing their energy-saving and environmentally friendly features. In conclusion, this paper emphasizes the critical role of multi-level converters in power systems and future energy applications, stressing the importance of their reliability and promising future developments.

Disassembly technologies for PEMFC stacks in heavy-duty applications

Hydrogen is one of the most promising solutions for decarbonising the industrial sector, particularly the chemical and steel industries. To utilise hydrogen as a mobile energy carrier in heavy-duty applications such as transportation, it is necessary to convert the chemically bound energy into electrical energy to power electrical systems. Fuel cell technologies, in particular Proton Exchange Membrane Fuel Cells (PEMFC), are crucial in this regard, as they efficiently convert hydrogen and oxygen into electricity and water.It is expected that production capacity will continue to grow, especially in the heavy-duty sector, and that the need for development will increase significantly. As a result, larger numbers of PEMFCs will reach the end of their life cycle. Successful closed-loop production requires optimising material use, making production processes more efficient, and recovering valuable materials. In order to optimise material, use and recover valuable resources such as platinum and fluorine-containing polymers and extend the product life cycle through reuse, aspects such as disassembly, reuse, remanufacturing and recycling must be considered before mass production.This publication aims to provide an overview of disassembly strategies and technologies for PEMFC stacks used in heavy-duty applications. It analyzes the general structure and layout of PEMFC stacks, with a focus on the Bipolar Plate (BPP), the Membrane Electrode Assembly (MEA) and the gaskets or seals. Various materials and designs of these components result in a wide spectrum of requirements regarding the handling and disassembly technologies. The outcome is a matrix show casing potential disassembly technologies for common PEMFC stack layouts, along with the expected limitations arising from different component and material combinations and their characteristics. The results of these investigations enable a more efficient development of automated disassembly processes for PEMFCs by providing appropriate guidance for suitable disassembly technologies.

Significantly Enhanced the Energy Density of Dielectric Composites by Sandwich Structure with Highly Insulating Mica Nanosheets.

Dielectric polymer composites exhibit great application prospects in advanced pulse power systems and electric systems. However, the decline of breakdown strength by loading of single high dielectric constant nanofiller hinders the sustained increase in energy density of the composites. Here, a sandwich-structured nanocomposite prepared with mica nanosheets as the second filler exhibits decoupled modulation of dielectric constant and breakdown strength. The traditional layered clay mineral mica is exfoliated into nanosheets and filled into polyvinylidene difluoride (PVDF), which shows a special depolarization effect in the polymer matrix. In Kelvin probe microscopy characterization and thermally stimulated depolarization current indicates that the mica nanosheets provided space charge traps for the polymer matrix and effectively suppressed the carrier motion. A sandwich structure composite material with mica nanosheets as the central layer has achieved a high energy density of 11.48 Jcm-3, 2.4 times higher than the pure PVDF film. This is due to the fact that randomly oriented distribution of nanosheets in a polymer matrix provide better current blocking. This work provides an effective method to improve the energy density of dielectric polymer composites by synergistically introducing insulating nanosheets and high dielectric constant nanofillers.

The Beginning of the Large-Scale Reconstruction of the Russian State Library: Architecture and Digitalization

The article reveals the foundations of design and research surveys, on the basis of which the Russian State Library (RSL) implemented the project of repair and restoration works for the central entrance of the library. The aim of the works was to adapt the cultural heritage object to modern use. The building complex, conceived in the mid — 1920s, was completed by 1940, but it was not fully commissioned until 1960. In the mid — 1970s, there was insufficient space to store the growing holdings. The front decoration of the central hall suffered enormous damage over the years. In 2019, a negative trend in the condition of the building was revealed. The main book depository was overloaded. The problems of the RSL are combined in a comprehensive investment programme for the reconstruction and restoration of infrastructure facilities. In 2019—2020, design solutions were developed for the repair and restoration of buildings and individual public spaces of the library. In 2021, the first stage of restoration of the entrance group began. The decision was made to carry out the work in a service-preserving environment and the challenge was to transform the very model of service to readers. The team working on the restoration made decisions reflecting the development of 21st century technologies and current standards for the automation of library processes. As a result of the works, new technological channels for the building operation and space for servicing readers were arranged, a climate control system was installed, the power supply and electric lighting system was replaced, historical interiors were restored, modern fire and engineering safety systems were created, a new centralized information and navigation complex for readers was deployed, etc. In 2023, a grandiose historical space was opened for the RSL readers.

Single-tuned passive filter (STPF) for mitigating harmonics in a 3-phase power system

Numerous integrals of the fundamental frequency are known as harmonics and can be found in power systems or electrical circuitry systems. Non-linear loads occasionally drain current or contains a varying impedance with each period of the AC voltage are often responsible for power system harmonics. This can result in system overheating, system losses, and equipment or system damage. In order to achieve the IEEE 519 power quality standard, filters are routinely employed to lower harmonic levels. In this work, we designed a single tuned passive filter (STPF) to minimize harmonics of sequence 5th, 7th, 11th, 13th, 17th, and 19th in a three (3) phase power system. The measurements were taken at the point of common coupling. To test the filter performance, the system and STPF were designed in MATLAB/Simulink, and the simulated results produced without and with STPF were compared. The {THD}_{I} was reduced from 14.93% down to 4.87% when STPF was connected which is within the IEEE 519-2022 standard; proving that the STPF was effective in decreasing the harmonics to the desired level.

Trends and Future Perspective of Electrification in Agricultural Tractor-Implement Applications

The worldwide growing demand for food is pushing the agricultural field towards new innovative solutions to increase the efficiency and productivity of cultivations. In this direction, agricultural mechanization plays a crucial role, and tractors are among the most important actors. Agricultural tractors are machines designed to push/pull special instruments usually referred to as implements, to which they may transfer power by means of a mechanical power take-off (PTO) or via hydraulic connections, thanks to the availability of pressurized oil. The tractor can be seen as a mobile power station: the more efficiently it provides power to external implements or to the ground in terms of tractive effort, the higher will be the efficiency and productivity of a certain task. However, the growing demand for greener and sustainable work machines is pushing towards new concepts of tractor powertrains with the goal of reducing, as much as possible, the amount of pollutants and GHG emissions per unit of work. In this paper, the authors will propose a review of the current trends towards electrification of agricultural tractors. Electrification can help in making vehicles more efficient and opening a new scenario for work optimization. Moreover, electrification is also involving the implements attached to the tractor and responsible for actually performing a wide variety of field tasks. However, tractor electrification requires proper attention due to the impact of high power electric systems on the vehicle configuration. For this reason, a proper level of hybridization should be considered. In this paper, a new classification method will be proposed, considering the electrification level in terms of power and as a function of the installed electric energy storage. This definition will be applied to classify the current state of the art of electric and hybrid agricultural tractors, investigating current trends in the scientific community and among industrial manufacturers with a look to the new upcoming technologies.

Multi-objective design of the energy storage-based combined heat and power off-grid system to supply of thermal and electricity consumption energies

Simultaneous consumption of electrical and thermal energy management, together with economic and technical advantages of close-to-consumption feeding of consumers, has demonstrated the importance of multi-carrier energy systems planning in recent years. Therefore, this paper presents the fuzzy decision-based multi-objective planning of an islanded hybrid system (IHS) with renewable energy sources (RESs), combined heat and power system (CHP), boiler, electric and thermal energy storage systems (ESSs) to provide a clean energy for electric and thermal consumers. Scheme is responsible for minimizing total weighted annual operating costs and pollution consumption of system. It is subjected to planning-operation constraints of sources and storages based on the electrical and thermal energy management. To obtain optimal solution with a low standard deviation error, a hybrid algorithm based on ant-lion optimizer and krill herd optimization is developed. Novelties include extraction of IHS with electric and thermal sources and ESSs, provision of clean energy to electrical and thermal consumers, extraction of scheme based on hybrid algorithm. By implementing scheme on data of Rafsanjan city in Iran and investigating numerical results, ability of design to obtain optimal hybrid combination of sources and storages to supply electric and thermal consumers from an economic and environmental point of view is confirmed. So that storage system (especially thermal storage) is able to reduce the planning cost and pollution level about to 1 %–6 % in compared with case including sources to supply thermal and electricity consumption energies. The aforementioned solution algorithm is able to extract the most optimal solution compared to non-combined algorithms and the standard deviation of its response is around 0.96. Fuzzy decision-making has obtained an optimal point for the aforementioned objective functions, which are about 20 % to 23 % away from their minimum value.

Design and Implementation of Solar Power System on Lettuce Hydroponic Greenhouse in Sekayu Musi Banyuasin Regency South Sumatera Province

Cultivation of lettuce in a greenhouse is considered a sustainable agricultural technique. Unlike conventional farming, which is susceptible to water shortages, pests, and other uncertainties that can lead to inconsistent and lower-quality lettuce production, hydroponic cultivation in a greenhouse ensures not only high-quality lettuce production but also continuous availability of crops, protected from extreme weather conditions such as droughts and pests. Although greenhouse cultivation is an effective approach, in lowland areas like Sekayu City, the capital of Musi Banyuasin Regency, the microclimate inside the greenhouse can be relatively high and less favorable for lettuce growth. Lettuce ideally thrives in highland regions with a temperature of around 28°C and humidity of 76%. Therefore, it is necessary to control the microclimate inside the greenhouse to optimize lettuce growth. This control requires electrical energy to operate various electronic devices in the microclimate control system, such as exhaust fans and cooling pad water pump. In this study, a solar power electrical system is designed to meet the energy needs for operating a lettuce greenhouse in Sekayu City, Musi Banyuasin Regency, South Sumatra Province. The research was conducted for 31 days, from July 1 to July 31, 2023. The highest power output was recorded on July 31, 2023, at 11 kWh, while the lowest output occurred on July 20, 2023, at 5 kWh. The research utilized an MMPT inverter, which prevents overcharging and maintains a constant 50 A input power when charging the battery. Additionally, an IoT system was used to monitor the performance of the solar power generation system, facilitating data collection on electricity production.

Bir İnceleme: Farklı Teknolojilerin Kullanımı ile Elektrik Enerjisi Depolama Sistemi Bağlantılı Hibrit Güç Sistemleri

Energy storage system is becoming crucial in the electric power system. It can response to economic, environmental, geopolitical and technological considerations. Energy storage system has a great role to covering energy for power electric system as renewable energy source, improves energy efficiency and promotes the integration of variable renewable energies, brings security and flexibility to networks, control and regulation. Several studies have been focused on different energy storage technologies connected to various hybrid energy systems to supply power to the grid /load. Almost of these recent papers have been mentioned the performance and the utility of storage system in term of management, control, cost, lifetime. For this reason, an overview is offered in this paper including hybrid energy system and using various energy storage technologies to generate electric power in the aim to clarify the use of diverse storage technologies from several sides as energy management strategy, control and optimization problems. A comparative study is made to demonstrate more the analysis of this paper.

EMI and IEMI Impacts on the Radio Communication Network of Electrified Railway Systems: A Critical Review

The electrified railway system has been rapidly rolled out in many countries and regions in the past decades, along with the transportation decarbonization agenda. The latest development in power electronics and electrical railway systems has increased the risks of electromagnetic interference (EMI) and intentional EMI (IEMI) emissions, introducing new challenges to the railway radio communications network. It is vital to have a robust and reliable railway communication network that can be resistant and immune to these interferences for the safe and efficient operation of modern railway systems. Yet, the source and new features of EMI and IEMI emerging along with the latest technological development have not been thoroughly investigated and understood. This review paper aims to fill the research gap. First, railway communications systems are introduced. The EMI and IEMI are discussed at the whole system level, and the corresponding impacts on the signaling and communication systems are reviewed comprehensively. Current electromagnetic compatibility (EMC) methods are surveyed, and challenges of tackling the impacts of EMI and IEMI on the signaling and communication systems are discussed. Finally, future research directions are outlined.

Achieving Excellent Dielectric and Energy Storage Performance in Core-Double-Shell-Structured Polyetherimide Nanocomposites.

The development of pulse power systems and electric power transmission systems urgently require the innovation of dielectric materials possessing high-temperature durability, high energy storage density, and efficient charge-discharge performance. This study introduces a core-double-shell-structured iron(II,III) oxide@barium titanate@silicon dioxide/polyetherimide (Fe3O4@BaTiO3@SiO2/PEI) nanocomposite, where the highly conductive Fe3O4 core provides the foundation for the formation of microcapacitor structures within the material. The inclusion of the ferroelectric ceramic BaTiO3 shell enhances the composite's polarization and interfacial polarization strength while impeding free charge transfer. The outer insulating SiO2 shell contributes excellent interface compatibility and charge isolation effects. With a filler content of 9 wt%, the Fe3O4@BaTiO3@SiO2/PEI nanocomposite achieves a dielectric constant of 10.6, a dielectric loss of 0.017, a high energy density of 5.82 J cm-3, and a charge-discharge efficiency (η) of 72%. The innovative aspect of this research is the design of nanoparticles with a core-double-shell structure and their PEI-based nanocomposites, effectively enhancing the dielectric and energy storage performance. This study provides new insights and experimental evidence for the design and development of high-performance dielectric materials, offering significant implications for the fields of electronic devices and energy storage.