Penelitian ini bertujuan untuk merancang dan membangun prototipe pembangkit listrik alternatif thermoelectric generator (TEG) sebagai media pembelajaran energi terbarukan yang efisien. Metode penelitian yang digunakan adalah ADDIE yang meliputi tahapan Analysis, Design, Development, Implementation, dan Evaluation. Komponen utama prototipe terdiri dari tungku briket batok kelapa sebagai sumber panas, empat buah modul Peltier SP 1848-27145 SA yang disusun seri, sistem pendingin air, serta boost converter XL6009 untuk menstabilkan tegangan keluaran. Hasil pengujian menunjukkan bahwa performa terbaik dicapai saat menggunakan sistem pendingin air radiator, dengan suhu sisi panas mencapai 150,5°C dan sisi dingin 34,9°C. Kondisi ini menghasilkan beda temperatur (ΔT) sebesar 115,6°C yang mampu membangkitkan tegangan hingga 3,44 Volt sebelum masuk ke boost converter. Melalui penggunaan boost converter, tegangan berhasil ditingkatkan menjadi 12,89 Volt untuk menyuplai beban lampu DC 10 Watt. Arus puncak yang dihasilkan tercatat sebesar 0,588 Ampere dengan daya listrik maksimum mencapai 7,58 Watt. Penelitian ini membuktikan bahwa prototipe mampu mengonversi energi panas menjadi listrik secara efektif untuk aplikasi skala kecil dan layak digunakan sebagai sarana edukasi teknologi energi baru terbarukan.
Kazakhstan is an agricultural country with a rapidly growing livestock sector. Every year, the country generates a significant amount of organic waste (manure, droppings), which, if not properly processed, becomes a source of pollution for soil, water bodies, and the atmosphere (emissions of methane and nitrous oxide). At the same time, the country is striving to achieve carbon neutrality by 2050, which requires the development of renewable energy sources. To estimate the total volume of livestock manure resources in Kazakhstan, its energy potential for biogas production, and the nitrogen and phosphorus load on agricultural land, as well as to identify regions with a high risk of pollution. Based on data from the National Statistics Bureau of the Republic of Kazakhstan for 2023–2024 on livestock and poultry populations, manure yield coefficients for various animal species, and organic fertilizer application standards (in accordance with Kazakhstani legislation and EU standards), calculations were performed for manure volumes, potential biogas yield, and the load on arable land across 17 regions and 3 cities of republican significance. The total volume of manure in Kazakhstan amounts to 124.7 million tons per year, with an energy potential of up to 4.1 billion m³ of biogas (equivalent to 2.45 billion m³ of natural gas). Cattle make the largest contribution (68% of the total volume). It has been found that in the Almaty, Turkestan, and North Kazakhstan regions, the nitrogen load on arable land exceeds environmentally safe standards (more than 170 kg/ha). At the same time, Kazakhstan ranks last in Central Asia in terms of mineral fertilizer use (only 2.4 kg/ha of nitrogen), which creates conditions for replacing them with organic fertilizers. Conclusions. The utilization of livestock waste through biogas technologies allows for simultaneously addressing energy shortages in rural regions, reducing greenhouse gas emissions (by 20–25 million tons of CO₂ equivalent per year), and obtaining organic fertilizers to restore soil fertility.
In the context of rapid digital transformation of industry driven by the Industry 4.0 paradigm, standardization and certification processes play a key role as tools for ensuring the sustainability, safety, and interoperability of digital solutions. At the same time, there is a growing need for comprehensive integration of automated control systems (ACS) into the regulatory and certification environment, as ACS form the foundation of modern manufacturing and energy systems, combining cyber-physical systems, industrial networks, digital twins, and elements of the Industrial Internet of Things (IIoT). In this context, the development of digital integration models becomes essential to ensure not only technological compatibility but also compliance with international standards and certification requirements. The article examines conceptual principles for implementing digital technologies in standardization and certification processes, relying on modern international standards (ISO 23247, IEC 62443, RAMI 4.0) and recent research on digital twins, intelligent control systems, and Quality 4.0. Particular attention is paid to the current state of digitalization in Kazakhstan’s industrial sector, where only about 12.9% of large and medium-sized enterprises apply Industry 4.0 technologies, despite state incentives such as co-financing of digital solutions. A three-level model for digital integration of ACS into standardization and certification frameworks is proposed, including operational, digital, and regulatory-certification levels. The model enhances process transparency, management quality, compliance with international practices, and systemic support for competency development, including personnel certification (e.g., SACA). An analytical review of the benefits, risks, and limitations of implementing such an architecture is provided, along with prospects for developing a national standardization system in the context of accelerated digitalization. The results confirm the need for comprehensive integration of ACS into standardization and certification processes as a key condition for successful Industry 4.0 implementation and enhancing the global competitiveness of manufacturing and energy enterprises.
Abstract This study focuses on enhancing isolation in dual polarization antennas operating at different modes in order to suppress coupling between transmitter (Tx) and receiver (Rx) without using any additional decoupling modelling. To validate the proposed investigation approach, a transmitter antenna was simulated at 150 GHz in vertical polarization (V-Pol), and the Rx works at 180 GHz in horizontal polarization (H-Pol). Later, both Tx and Rx were coupled in such a way that they excite in orthogonal directions to each other, implying that the angle between Tx and Rx is approximately 90 degrees. In this case, the Tx will function in TM21 resonance mode, having an operational bandwidth of 10 GHz at 150 GHz. While Rx will operate in TE20 mode, with an operational bandwidth of more than 10 GHz at 180 GHz. This research achieves more than 30 dB isolation simply by allowing Tx and Rx to operate in different modes under an orthogonal feeding setup. The proposed antenna provides better than | S 12| > 30 dB isolation with an isolation bandwidth of 51.42% in the sub-THz range from 130 GHz to 220 GHz without the need for an extra decoupling mechanism. Finally, the results of the proposed research were validated using HFSS and FEKO electromagnetic tools to explain simulation outcomes such as return loss, isolation, radiation efficiency, peak gain, and radiation patterns.
This paper presents a detailed analysis of losses and efficiency in a 200 kVA three-phase distribution transformer under various loading conditions. Transformer losses, which account for approximately one-third of total energy transmission and distribution losses, are divided into no-load and load losses. The study emphasizes the impact of non-linear loads, such as variable-speed drives, computers, UPS systems, and energy-saving lamps, which generate harmonic currents leading to increased eddy current and core losses. A MATLAB-based model of the transformer was developed using factory-provided data from Mazoon Electricity Company, including equivalent circuit parameters and B-H magnetization characteristics. The transformer’s performance was evaluated under full load, half load, unbalanced load, and non-linear load conditions, with the efficiency calculated for each scenario. Results indicate that harmonic currents significantly affect load losses, causing a reduction in overall efficiency. Mitigation strategies, including single-tuned shunt filters and improved magnetic materials, are discussed to reduce harmonic-induced losses. The paper also highlights the economic and environmental benefits of investing in energy-efficient transformers, including reduced lifecycle costs and enhanced reliability. Finally, common transformer failures and their classification according to severity, frequency, and detectability are analyzed, emphasizing the importance of preventive measures and early fault detection.
Rural electrical networks are characterized by their extensive length, low density of electrical load, and heightened vulnerability to failures. Modern management and automation technologies, including IoT devices and internet-based solutions, enhance the efficiency of such networks but simultaneously increase their susceptibility to cyberattacks. Targeted attacks on critical points of rural network infrastructure can lead to significant disruptions, resulting in financial losses and reduced resilience of agricultural production. The aim of this study is to develop a model of cyberattacks on rural electrical networks and protection methods using Nash's method, which allows for consideration of the strategic interaction between attackers and defenders to improve the resilience of such systems. The research is based on Nash's method from game theory. The model describes the interaction between an attacker and a defender as strategic players, defines their utility functions, and identifies possible strategies. Special attention is given to the distributed structure of rural networks, seasonal load fluctuations, and the integration of renewable energy sources. The developed model enables the assessment of vulnerabilities in rural networks and the prediction of player behavior over time. Attackers may use false signals and manipulate network parameters, while defenders implement monitoring and redundancy measures. The introduction of adaptive protection mechanisms significantly reduces the risk of successful attacks. Modeling the interaction between attackers and defenders using Nash's method provides an effective tool for analyzing cyber threats and developing protection strategies for rural electrical networks. The model accounts for the specific characteristics of rural electrical networks, contributing to improved reliability and minimizing the financial and operational consequences of cyberattacks.
At present, technologies whose production processes are environmentally benign are becoming increasingly relevant. The aim of this paper is to investigate the efficiency of light capture of a newly developed light-collecting dome for a light guide. This article presents a study of a novel design of a specialized light-collecting dome for a light guide.A new dome geometry in the form of a truncated hemisphere is proposed, enabling an increase in the efficiency of light guides. The paper provides an overview of the effects and phenomena that can be employed in the development of a solar concentrator, and substantiates the selection of the specific physical principle used – namely, specular reflection. Technical solutions to the stated problem are developed, and the choice of a particular design solution is justified based on the technical capabilities of the customer. The geometry of the concentrator elements is calculated based on ray-tracing constructions of parallel rays incident at angles ranging from 20° to 90°. In conclusion, the efficiency of the concentrator is evaluated based on the increase in the effective light-collecting area. The conducted constructions and calculations show that, for direct solar radiation (20°–45°), the average increase in the effective working light-collecting area amounts to a factor of 1.518, or 51.8%. For diffuse solar radiation (20°–60°), the average increase is 1.394 times, or 39.4%.
The article presents an intelligent control strategy for a photovoltaic (PV) inverter for its integration into smart power systems. The proposed control system includes a controller on the side of the photovoltaic installation, which tracks the maximum power point, as well as a network controller designed to regulate the active and reactive power transmitted to the electrical grid through the inverter. A Volt-VAR regulator is proposed to control reactive power exchange depending on the voltage at the point of common connection (PCC). The coefficients of proportional-integral (PI) regulators are tuned using a genetic algorithm through adaptive online optimization. The effectiveness of the proposed control method has been verified on a 33-node radial distribution network in the MATLAB/SimPowerSystems environment. The simulation results showed that the optimized Volt–VAR control strategy provides stable dynamic characteristics under changing climatic conditions, improves voltage control quality, and contributes to the efficient use of photovoltaic distributed generators by maximizing power extraction and supporting grid voltage.
Food, water, and energy represent the fundamental requirements of human society, and their interdependence forms a critical relationship often referred to as the food–water–energy nexus. Among these components, energy plays a vital role in maintaining life, supporting technological progress, and driving economic development. However, the rapid growth in energy demand, along with the depletion of conventional resources and increasing environmental concerns, has led to significant global challenges, including energy shortages and ecological degradation. In this context, thermoelectric energy conversion has gained attention as a promising approach to addressing these issues in the modern era. Thermoelectric systems have the ability to directly transform heat into electrical power through the Seebeck effect, which makes them particularly useful for recovering waste heat and enabling distributed power generation. This paper presents an overview of thermoelectric technology, highlighting its operating principles, importance, and the classification of thermoelectric generators (TEGs). Additionally, the study examines the materials utilized in thermoelectric devices, focusing on their thermal and electrical characteristics, as well as their impact on system efficiency. Recent developments in advanced materials, including semiconductor-based and nanostructured compounds, are also discussed due to their significant contribution to improving energy conversion performance. The paper further explores key design aspects and optimization strategies aimed at enhancing the effectiveness of TEG systems. Various applications of thermoelectric generators are reviewed, such as their use in industrial processes for waste heat recovery, automotive technologies, space exploration, and small-scale energy systems. These examples demonstrate the flexibility and growing importance of thermoelectric solutions across multiple sectors. Finally, the paper identifies existing limitations and outlines potential directions for future research in thermoelectric power generation. Emphasis is placed on improving material performance, reducing production costs, and developing more efficient system designs. Overall, thermoelectric technology offers a sustainable and environmentally responsible pathway to help mitigate current energy challenges.
Penelitian ini bertujuan untuk menganalisis konsep dasar sistem kendali dalam perspektif rekayasa sistem serta mengkaji perannya dalam pengelolaan sistem teknologi modern yang kompleks. Penelitian menggunakan pendekatan kualitatif dengan metode deskriptif melalui studi pustaka terhadap berbagai sumber literatur akademik, termasuk buku ilmiah dan artikel jurnal yang relevan. Proses analisis dilakukan melalui identifikasi tema, reduksi data, kategorisasi konsep, serta penarikan kesimpulan secara induktif guna memperoleh pemahaman yang komprehensif. Hasil penelitian menunjukkan bahwa sistem kendali memiliki peran krusial dalam mengelola sistem dinamis melalui mekanisme umpan balik, stabilitas, dan optimasi kinerja. Dalam konteks rekayasa sistem, sistem kendali berfungsi sebagai elemen integratif yang memastikan koordinasi antar subsistem dalam lingkungan yang kompleks dan berubah. Perkembangan teknologi mutakhir juga mendorong integrasi sistem kendali dengan pendekatan seperti pembelajaran mesin, sistem siber-fisik, dan digital twin, yang memungkinkan peningkatan kemampuan adaptasi, efisiensi, serta keandalan sistem. Implikasi penelitian ini menegaskan bahwa pemahaman konseptual dan integratif terhadap sistem kendali sangat penting dalam pengembangan sistem teknologi modern, khususnya pada bidang robotika, energi, dan industri cerdas. Selain itu, integrasi teknologi digital dalam sistem kendali membuka peluang bagi inovasi lanjutan dalam pengembangan sistem yang lebih otonom dan responsif terhadap perubahan lingkungan.
This paper presents the results of simulation modeling of renewable energy source integration – specifically a solar photovoltaic (PV) plant – into a smart grid using MATLAB/Simulink R2022b. The developed model comprises a 2.19 MW PV array based on A10 Green Technology A10J-M60-220 modules, a boost converter, a three-phase IGBT-based inverter with pulse-width modulation (PWM), and combined RLC filters for harmonic suppression. The grid topology includes three synchronous generators (6.6 kV – primary, two at 3.3 kV – backup), a 100 km transmission line, and a distribution system supplying industrial load at 1100 V and domestic load at 440 V. Simulation was conducted in two stages: analysis of grid operation without renewable integration, followed by evaluation of system parameters after PV plant connection. Results demonstrate that the application of RLC filters with parameters R = 1 mΩ, L = 1 mH (series circuit) and R = 100 kΩ, C = 1 nF (parallel circuit) effectively suppresses harmonic distortions generated by the inverter, ensuring sinusoidal voltage waveforms at all monitoring points. It was established that during parallel operation of the 3.3 kV generators with the PV plant, the grid voltage reaches 5200 V-1200 V lower than when operating solely with synchronous generators – confirming that renewable sources cannot fully replace conventional generation. However, the PV plant effectively performs a supporting role, contributing to voltage stabilization and system reliability during low-demand periods.
This paper presents the procedure for calculating the electric field level in the vicinity of base stations (BS) implemented in 5G technology. The specificity of the 5G system is the application of dynamic routing of traffic radiation beams directly towards active users (beamforming). In the paper, the following characteristics are calculated: 1. maximum field level; 2. mean field level without application of power control and 3. mean field level with application of radiated power control in the BS for traffic channels depending on the distance from the BS, taking into account only the field created by the considered BS, not the neighbouring ones. In this calculation, a uniform distribution of user density in the BS cell and an equal traffic load of all users during a sufficiently long-time interval were assumed. The parameters that change in the graphs are the characteristics of the applied antenna (width of its main radiation beam, gain in the main and side radiation beams), BS height and radius of the BS cell. The most interesting result is that the mean level of radiation in the case of application of control of the emitted power can also increase with increasing distance from the BS, whereby the shape of the obtained characteristics depends on the radius of the BS cell. However, in an absolute sense, the level of the electric field in this case is lower than the values allowed by regulations and can pose a danger only through the aggregate value with other sources of radiation.
This paper presents a modified approach to implementing Sigma Point Kalman Filters (SPKFs), in which the Singular Value Decomposition (SVD) of the covariance matrix is used to generate sigma points for the unscented transform. The advantage of the proposed approach is that it requires just (n+1) instead of the usual (2n+1) sigma-points with only a minor reduction of precision. The proposed method for selecting the sigma-points to adjust the normal process parameters during the update phase of the filter can be intuitively visualized in the 2D case by plotting the covariance ellipsoid. The proposed reduced sigma-point filter achieved satisfactory performance in a case study involving state-of-charge (SoC) estimation for vehicular batteries when compared to the original SPKF implementation.
A voltage differencing buffered amplifier (VDBA) and a current differencing buffered amplifier (CDBA) are used in the proposed compact meminductor emulator design. The proposed emulator reduces the passive components number by utilizing parasitic components of CDBA to obtain a compact layout. This feature also aids in the realized circuit's ability to operate at a high frequency. The element in the suggested design has memory of its previous state, since the effective meminductance is dependent on the total charge stored on the capacitors. By altering the capacitance values, pinched hysteresis loops between magnetic flux (Phi) and current (i) are shown throughout a broad frequency range (1 kHz to 3 MHz). Both incremental and decremental hysteresis assessments, non-volatility measures, and transient response tests verify that the suggested emulator is operating correctly. The theoretical predictions are closely matched with LTspice simulations utilizing 0.18 & micro;m process characteristics. The non-ideal analysis of the suggested configuration verifies the accuracy of the derived expressions and simulation results. Lastly, the meminductor practical application in actual circuits is confirmed by incorporating it into a chaotic oscillator.
This work presents a compact floating configuration of the memtranstor (MT), a recently introduced memory element defined by the direct relationship between magnetic flux (phi) and charge (q). Unlike prior designs, the proposed emulator eliminates the need for multipliers or other complex circuitry, resulting in a simplified and power-efficient architecture. The circuit employs a single voltage differential transconductance amplifier (VDTA) and one voltage differential current conveyor (VDCC) as active devices, together with three grounded capacitors and one grounded electronic resistor as passive components. The emulator successfully reproduces the fundamental phi-q relationship and exhibits origin-crossing pinched hysteresis loops under sinusoidal excitation - a defining characteristic of memtranstive systems. It operates reliably at a supply voltage of +/- 0.9V and supports electronic tunability through adjustment of the VDTA and VDCC transconductance parameters), ensuring adaptability across a wide range of operating conditions. Extensive validation was carried out through mathematical modeling and LTSpice simulations based on a 180-nm CMOS process. The evaluation includes demonstration of memory effects, Monte Carlo analysis, temperature sensitivity studies, and characterization of pinched hysteresis loops under variations in DC control voltage, excitation frequency, and transconductance values. A full-custom layout was implemented, occupying a silicon area of 2529.49 mu m & sup2;. Non-ideal effects, including parasitics at active device terminals, were also thoroughly analyzed to ensure functional robustness. Distinguished by its compact structure, low component count, and ease of integration, the proposed design provides a robust and efficient platform for MT-based applications. Its demonstrated performance highlights significant potential for neuromorphic computing, chaos-based systems, nonlinear dynamics, and other emerging analog memory-oriented domains.
With the ever-increasing realization of the limitations of the radio frequency (RF) spectrum in the evolution towards 5G and 6G communication systems, VLC has been recognized as a high-speed and secure communication system that supports gigabit-per-second data rates. However, in most cases, VLC communication systems are often hampered by issues related to line-of-sight (LOS) propagation and signal shadowing. This paper proposes the optimization of indoor VLC communication systems through the lighting geometry.Using the simulation environment set up in the 5 m & times; 5 m & times; 3 m indoor environment and carried out for different LED array patterns including single-centred patterns, square patterns, and circular patterns of 12-LEDs with a radius of 1.5 m, it was determined that the 12-LED array pattern with a radius of 1.5 m lead to an average SNR of 36.7 dB, a BER of 2.5 & times;10-9, and Fa of 8.24. The superiority of the proposed system was strictly observed in terms of significant improvement over the standard array patterns. Also, from the research carried out, it was ascertained that the proposed system can attain high-order modulation constellations of 256-QAM. The findings of the study clearly highlight that the collaboration of geometric organization and intelligent surfaces is critical in the design of future IoT-enabled communications and smart buildings requiring high spectral efficiency.
