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Elektr energiyasi iste’molini uzoq muddatli prognozlash uchun dastlabki ma’lumotlarni tasdiqlash
Relevance: modern developments in the electric power industry are accompanied by increasing uncertainty in consumer behavior, a growing share of distributed energy sources, and the implementation of new digital and intelligent technologies. Under these conditions, long-term forecasting of electricity demand becomes a critical tool for strategic planning, substantiation of investment decisions, design of new power systems, and formation of a sustainable energy development strategy. The accuracy of the forecast directly depends on the quality of the initial data used in analytical and modeling procedures. Actual consumption data obtained from automated metering systems often contain outliers, gaps, and systematic distortions caused by both technical and organizational factors. Neglecting the data verification stage can lead to distortions in predictive models, which, in turn, results in errors in assessing capacity needs, energy production and supply volumes, as well as in grid infrastructure calculations. Therefore, verification of initial data is considered the most important stage of long-term demand forecasting, ensuring the reliability and informational completeness of calculations. The application of robust statistical methods, such as interquartile range analysis, allows for a significant improvement in the credibility of forecast scenarios and minimizes the risks of erroneous strategic decisions in the electric power sector. Aim: to verify the initial data for use in the development of mathematical models for long-term electricity consumption forecasting. Methods: there was used the interquartile range statistical method. Results: the application of the interquartile range (IQR) method revealed no outliers in the initial data on electricity consumption, temperature, population, and GDP. This indicates high quality and stability of the data, providing a reliable foundation for developing long-term energy consumption forecasting models.
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Real-Time Monitoring and Diagnostics for Enhanc-ing Central Inverter Efficiency in Large-Scale Solar Power Plants
Relevance: the large-scale deployment of solar power plants has highlighted the importance of improving the efficiency and reliability of central inverters. Central inverters represent both the most critical and the most failure-prone element of the entire system. Failures occurring in inverters account for up to 20–25% of downtime and cause energy losses of 1.5–2.5% of total generation. Therefore, the application of real-time monitoring and diagnostic (RTM&D) methods has significant scientific and practical value, as it enables higher inverter efficiency, reduced operational costs, and lower electricity production costs. Objective: to develop and validate real-time monitoring and diagnostic (RTM&D) systems aimed at improving the efficiency, reliability, and additional energy yield of central inverters in large-scale solar power plants. Methods: during the research, sensor-based systems were employed to continuously track electrical parameters , thermal conditions, and fault signals. Data collection technologies were based on SCADA systems. Inverter efficiency was calculated as: Diagnostic algorithms employed artificial intelligence techniques, specifically a Support Vector Machine (SVM) classifier, alongside models for calculating thermal and conduction losses in semiconductor switches. Results: according to the findings, the monitored central inverters achieved an efficiency increase from 94.2% to 96.8%, while average monthly downtime was reduced by 18%, and mean time to repair (MTTR) decreased by 24%. Additionally, the system enabled annual savings of several hundred MWh of electricity through increased production. The proposed approach provides advantages such as real-time operation, improved diagnostic accuracy, and more effective preventive maintenance scheduling.
Copyright (c) 2026 https://creativecommons.org/licenses/by-nc-nd/4.0
Energy Clustering during Uzbekistan’s Energy Transition
Relevance: Uzbekistan's modern energy sector, like global energy, is characterized by the process of energy transition towards alternative energy and is accompanied by innovative processes related to energy clustering. This creates a need to analyze the effectiveness of the cluster approach, the emerging synergy in implementing the energy transition, and for the further development of the energy sector. The article examines the cluster approach for the effective development of the energy sector during Uzbekistan's energy transition. An analysis of the creation of energy clusters based on alternative and renewable energy sources (ARE) has been conducted. Proposals have been developed for organizing energy clusters in Uzbekistan to rationalize the energy transition and further develop the electricity sector. Aim: to analyze and determine the conditions for using the cluster approach during Uzbekistan's energy transition and for the development of the republic's energy sector based on its clustering. Methods: international experience in creating energy clusters, as well as the potential of Uzbekistan's energy sector, are analyzed and utilized. Results: proposals have been developed for the creation of energy clusters during the implementation of Uzbekistan's energy transition and for the further development of the republic's energy sector.
Investigation of the Performance of a Low-Energy Capillary-Evaporative Air Purification Device in the Dust- and Salt-Laden Environment of Karakalpakstan
Relevance: Currently, in the Republic of Karakalpakstan and the Aral Sea region, air pollution, the spread of saline aerosols, and high summer temperatures have a significant impact on public health. Fine salt particles (PM10, PM2.5, PM1.0), transported by wind under the region’s climatic conditions, exacerbate respiratory diseases, while indoor air quality remains below regulatory standards. In addition, most existing air conditioners and air purifiers are characterized by high energy consumption; their filters quickly become clogged in saline air, leading to increased operational costs. In a region rich in solar energy yet characterized by hot and arid weather, the demand for energy-efficient, autonomous devices capable of stable operation in a saline environment is growing. From this perspective, the development of a new type of device based on capillary evaporation, utilizing a bidirectional airflow and equipped with HEPA filtration, is highly relevant both scientifically and practically. The advantage of this technology lies in its minimal demand for external power, its autonomous operation using a solar panel and a low-power fan, and its ability to simultaneously humidify, cool, and purify the air while remaining resistant to salt particles. As a result, the device can improve indoor air quality in residential buildings, schools, hospitals, offices, and public facilities. Furthermore, manufacturing such a device using local raw materials and ensuring low maintenance costs make it economically competitive. Its energy efficiency and low operating expenses increase the potential for large-scale implementation and commercialization. Aim: Development of an energy-efficient air purification and passive cooling device adapted to the climatic conditions of Karakalpakstan, based on capillary evaporation and utilizing bidirectional airflow; scientific justification of its aerodynamic and thermodynamic characteristics, as well as experimental evaluation of the device’s operational stability and performance when powered by alternative energy sources. Methods: The study employed aerodynamic calculation methods, analysis of air velocity and pressure distribution based on Bernoulli’s principle, laboratory measurements of the evaporation efficiency of the capillary material, as well as an experimental assessment of the reduction in dust and salt particle concentrations achieved through HEPA filtration. Results: The study results indicate that passive cooling via capillary evaporation provides a temperature reduction of 5–10 °C, HEPA filtration significantly decreases the concentration of airborne particles (PM10, PM2.5, PM1.0), and the device’s overall energy consumption is substantially lower compared to conventional ventilation and cooling systems. When integrated with a solar panel, the device is capable of fully autonomous operation.
Analysis of the flexibility of Uzbekistan’s power system under increasing shares of variable renewable energy generation
Relevance: In the context of the global energy transition aimed at reducing carbon intensity and increasing the sustainability of energy systems, the integration of renewable energy sources (RES) into national energy balances is gaining particular importance. The Republic of Uzbekistan, possessing significant solar and wind energy potential, is actively implementing a strategy for transitioning to “green” energy. According to the target indicators [15] approved by the Senate of the Republic of Uzbekistan, by 2030 it is planned to reach 27 GW of installed renewable energy capacity, which represents up to 54% of the total power system capacity of the country. The achievement of these goals will make it possible to save about 25 billion m³ of natural gas annually and reduce CO₂ emissions by 34 million tons, which is of strategic importance for ensuring energy security and fulfilling the country's international climate commitments. However, the increasing share of variable generation from solar (PV) and wind (WPP) power plants, combined with changes in power demand, necessitates a comprehensive analysis of operating conditions and system flexibility to ensure stable functioning of the power grid. The variability of renewable energy generation and electricity demand, as well as their dependence on weather conditions, require a high degree of flexibility and the ability to promptly manage the power balance. At the same time, a significant portion of Uzbekistan’s generating capacity is represented by gas-fired thermal power plants, including combined-cycle gas turbine (CCGT) units, highly flexible gas-piston units, as well as battery energy storage systems and hydropower plants, which allows assessing the system’s adaptability to RES and demand fluctuations. Thus, the analysis of system flexibility and the development of recommendations for improving operational control under the conditions of increasing variable renewable energy generation and demand becomes a highly relevant task, essential for ensuring the reliability, resilience, and efficiency of the power system. Aim: To perform a comparative analysis of the flexibility assessment results with the actual operating conditions of the power system. Methods: There were used a research method was applied that includes statistical time-series analysis to assess the variability of PV and wind power generation as well as demand dynamics. statistical methods of analysis and forecasting. Results: As a result of the distribution of power among different types of sources involved in covering the required regulation range, the following shares were obtained: gas-piston power plants (GPPP): ≈40,5%; hydropower plants (HPP) ≈17,3%; Battery energy storage systems (BESS) ≈17,3%; Thermal power plants + combined-cycle gas turbines (TPP + CCGT, spinning reserve) ≈24,9%.
Rust and pollution protection of the rotating regenerative air - heaters of the boilers
Relevance: in order to reduce corrosion and pollution of regenerative air-heaters in gas and mazut boilers during the combustion of sulfurous oil or gas fuels, it is common practice to preheat the air supplied to the cold-end packages of the air-heaters. This air preheating is typically achieved using a calorifier unit, which is fed by steam extracted from turbine take-offs. To minimize boiler efficiency losses and to keep corrosion and pollution levels within permissible limits under conditions of rapidly varying boiler loads, it becomes necessary to regulate the temperature of the preheated air. However, the standard existing layouts for removing heating steam condensate from the calorifier unit do not ensure a reliable hydrodynamic regime for two-phase flow under such conditions. They also fail to prevent steam from entering the condensate-collecting lower chambers. This paper presents the results of our research on the development and implementation of a patentable automatic control system for regulating the air preheating temperature in the steam calorifier unit of gas-and-mazut boilers. Additionally, it introduces a specially designed device to eliminate hydraulic shocks in the steam condensate removal system and proposes a new flow diagram for the calorifier unit in the TGM-94 gas-and-mazut boiler of a 160 MW power unit. Aim: to improve the efficiency and reliability of power boiler operation during combined or separate combustion of sulfur-containing fuels, including natural gas and fuel oil. Methods: theoretical approaches and practical methods of optimizing the operation of power boilers and their automatic control systems under combined combustion of sulfur-containing fuels were used. Results: the results of studies on the serial implementation of a new technology and an automatic control system for operational parameters in TGМ-94 boilers during combined combustion of natural gas and fuel oil are presented.
Mathematical modeling of low-voltage distribution electrical networks
Relevance: the current three-phase 0.4 kV distribution electrical networks are the main link in the power supply system. Load asymmetry in networks, phase imbalance, and insufficient real-time monitoring reduce the quality and reliability of electricity. Moreover, in the context of implementing an automated system for commercial electricity metering (ASCAE), an urgent task is to ensure the operational monitoring and analysis of the distribution electrical network through its mathematical modeling. This not only allows for the detection of electrical energy losses but also for the assessment of the main line parameters and the monitoring of dynamic load changes in real time. Therefore, the development of accurate mathematical models of unbalanced three-phase networks and the improvement of methods for their analysis are of significant practical importance. Aim: development of a mathematical model of unbalanced three-phase 0.4 kV distribution electrical networks, improvement of methods for determining unmeasured currents and voltages in real-time, as well as the creation of efficient algorithms for their application in an ASCAE system. Methods: the study employed a methodology of mathematical modeling based on electrical circuit theory, digital signal processing, and methods of identification and optimization. The current and voltage values in the unbalanced mode were decomposed into symmetrical components, and the unmeasured parameters were estimated using correlation and adaptive calculation methods. During the data collection and analysis process, ASCAE telecommunication modules and the corresponding functions of data concentrators were used. Results: as a result of the study, a mathematical model of an unbalanced three-phase 0.4 kV network was developed, which improved the accuracy of determining unmeasured electrical quantities. The proposed method enables the assessment of power quality indicators in the network, the determination of the current values of the main line resistances, and the monitoring of energy losses. The obtained results can be implemented in the ASCAE system, which will significantly improve the efficiency of the distribution electrical network and the level of its control.
Mathematical model and algorithm for optimizing the composition of elements in an autonomously operating wind power station
Relevance: in modern conditions of intensive increase in electricity consumption, limited hydrocarbon fuel reserves, as well as the severity of environmental problems in the energy sector, it is important to develop and implement more advanced methods for the design and operation of power plants operating on renewable energy resources. One of the main tasks in designing autonomous systems with stations using these types of energy resources is choosing the optimal composition of the equipment used. Despite the current existence of a number of developments and programs to solve this problem, improving them by taking into account all limiting and influencing factors, increasing the reliability and accuracy of optimization calculations remains as an urgent task. Aim: is to develop and implement more improved methods of designing and operating power plants working on renewable energy resources. Methods: an effective mathematical model for choosing the optimal composition of autonomous system equipment, which includes a wind power plant and a storage battery, and an algorithm based on solving it by applying the simplex method to the problem of linear programming is proposed. Results: the effectiveness of the mathematical model and optimization algorithm is explained by the optimal selection of parameters of wind units and accumulator batteries in an autonomous system with a consumer operating according to a given daily load schedule.
PV generation control to enhance the energy efficiency of local power supply systems
Relevance: in recent years, an increasing number of commercial and industrial (C&I) organizations in Uzbekistan have been installing small-scale grid-tied photovoltaic (PV) power plants. Typically, photovoltaic modules (PVMs) are installed on the rooftops of C&I buildings where the main electricity consumers are concentrated. Therefore, from the standpoint of reducing electricity losses, the most rational solution is to connect the PV plant to the building’s own main distribution board (MDB). However, in many implemented projects, in accordance with the issued technical specifications, the PV plant is connected via a new cable to the low-voltage busbars of a transformer substation (TS) located at a certain distance from the building. Such an arrangement leads to additional electricity losses both in the cable between the grid-tied inverter and the TS, and in the cable running from the TS to the MDB. Aim: to study the advantages of connecting a grid-tied PV plant directly to the MDB compared to connecting it to the TS, as well as to examine the technical limitations of such a connection and possible methods for their mitigation. Methods: development and implementation of an automatic control system that regulates PV generation and consumer loads to ensure the stability of a local isolated power system (microgrid) with two generation sources — a diesel generator (DG) and a grid-tied PV plant. Results: reduction of electricity losses by minimizing the distance between the generation source (PV plant) and the main consumers powered from the MDB, as well as by unloading the feeder cable between the TS and the MDB. Reduction of diesel fuel consumption by up to 60% during emergency power supply from the DG.
Problems of increasing the reliability of electric motors and methods of their solution
significantly lower than the rate of their modernization. Thus, during the operation of electric motors, they are triggered, which increases their reliability. Mazda has proposed more modern operating conditions for electric motors, which would improve the reliability of their operation. Aim: The reliability of electric motors is currently one of the most important components of their reliability, making them reliable, adaptive and intelligent units in the operation of electric motors. A feasibility study is required to prevent accidents on paved roads that may lead to the destruction or damage of the cladding. Methods: In order to increase the reliability of electric motors, they used rational and intelligent methods based on technology. Results: An intelligent monitoring system based on the RUL (Remaining Useful Life — Remaining) methodology for predicting the technical condition of electric motors. Similar results were obtained in the antimonopoly regime, including in the framework of the mandatory medical examination system.
Energy efficiency issues of thyristor-controlled reac-tive power compensators
Relevance: In railway power supply systems, traction loads vary sharply depending on train operating modes, which leads to an increase in reactive power in the contact network and traction substations. High levels of reactive power cause voltage drops, a reduction in the power factor, and deterioration of power quality. Failures in reactive power compensation systems negatively affect traction stability, resulting in reduced train speeds and decreased freight transportation volumes. Conventional compensation devices do not provide sufficient accuracy and response speed under variable and unbalanced load conditions characteristic of railway systems. Therefore, the study of devices that ensure fast, reliable, and energy-efficient reactive power compensation in railway power supply systems is a relevant scientific and practical task. Aim: The objective of this study is to conduct a scientifically grounded analysis of the impact of reactive power on voltage stability and power factor in railway power supply systems, to evaluate the operating characteristics of a reactive power compensation system based on a thyristor-controlled capacitor, and to identify ways to improve its energy efficiency and reliability. Methods: In this study, formulas for active, reactive, and apparent power based on sinusoidal circuit theory were used to determine and evaluate reactive power. To calculate and control reactive power in real time, a mathematical model based on the instantaneous power theory proposed by Akagi was developed, and its suitability for fast control algorithms was substantiated. A comparative analysis of the technical characteristics of various reactive power compensators was performed. In the thyristor-controlled capacitor, heat dissipation processes, the thermal resistance chain, cooling methods (natural and forced air cooling, and liquid cooling), as well as commutation processes were analyzed. Results: The technical advantages of applying a thyristor-controlled capacitor with a star connection scheme were identified. This configuration enables independent phase-by-phase reactive power compensation and effectively maintains voltage stability under three-phase unbalanced load conditions. The results show that the overall efficiency of the compensation system depends not only on the selected electrical scheme but also on the thermal operating conditions of the thyristors, the reliability of the cooling system, and proper organization of maintenance.
Analysis of the thermohydraulic parameters of the condenser–heat exchanger of a pyrolysis bioenergy plant
Relevance: the modern development of bioenergy is driven by the need to identify sustainable and environmentally clean energy sources. Biomass pyrolysis processes are of particular interest, since they allow not only the utilization of agricultural and wood residues but also the production of valuable outputs in the form of fuels, heat, and chemical compounds. One of the key components of pyrolysis plants is the condenser–heat exchanger, which ensures efficient condensation of the vapor–gas mixture and recovery of heat. The overall energy efficiency of the installation, as well as the stability and safety of the technological process, directly depend on its performance. Under the conditions of increasing requirements for energy saving, emission reduction, and enhanced reliability of equipment, the study of thermohydraulic processes in condensers becomes especially relevant. Such analysis makes it possible to justify optimal operating parameters, improve the overall heat transfer coefficient, and reduce hydraulic losses, which ultimately contributes to the development of more efficient and environmentally oriented bioenergy technologies. Aim: analysis of the thermohydraulic characteristics of a condenser–heat exchanger of a pyrolysis-based bioenergy system considering phase transitions of the vapor–gas mixture. The study is aimed at substantiating the optimal operating parameters and enhancing heat transfer efficiency while simultaneously reducing hydraulic losses. Methods: analytical calculation methods, empirical correlations, Xin–Ebadian correlations, regression analysis methods, experimental measurements using thermocouples, a manometer and a pyrometer, as well as numerical modeling in the COMSOL Multiphysics environment were employed. Results: it has been established that the overall heat transfer coefficient of the condenser strongly depends on the mass flow rate of the cooling water and the temperature driving force between the pyrolysis gas–vapor mixture and the coolant. With an increase in water flow rate, the heat transfer coefficient rises from 165.7 to 193.3 W/m²·K. The calculated data show good agreement with the experimental results, and the condensation zone maps revealed that the highest heat transfer intensity occurs at the inlet of the gas–vapor mixture, gradually decreasing along the coil length, which provides a basis for justifying the rational design parameters and operating conditions of the condenser.
Optimization of the placement and capacity of small-scale generation sources in distribution power networks
Relevance: At present, the integration of low-power generation sources into electrical power systems is one of the most relevant research areas worldwide. The use of such sources enhances the reliability of power supply, reduces the load on centralized grids, and decreases energy losses. Furthermore, the application of renewable and environmentally friendly energy sources is a priority direction of the national energy policy, playing a crucial role in ensuring the stability and efficiency of power systems. Aim: The main objective of the research is to minimize electrical energy losses by determining the optimal placement points and power capacities of low-power generation sources in distribution networks. Achieving this goal allows for stabilizing the operation mode of distribution systems, normalizing voltage levels, and improving the overall energy efficiency of the grid. Methods: The study employs a mixed nonlinear integer programming model. To obtain the optimal solution, a modified Kelley cutting-plane method and genetic algorithms were applied. Computational modeling was carried out using the GAMS (General Algebraic Modeling System) and RASTR software environments. An experimental model based on a 30-node radial distribution network was developed to analyze voltage parameters and power losses. Results: Modeling results indicate that installing a 2.055 MW distributed generation source at node No. 7 reduces active power losses from 218 kW to 113.7 kW. This confirms the efficiency of the proposed optimization approach and its practical significance for improving the operating conditions of electrical distribution networks. The obtained results show good agreement with full-variant calculations, which validates the reliability of the proposed methodology.
Development of production of modular boiler plants in Uzbekistan and their comparative analysis
Relevance: studies of heating networks, conducted in cities of the republic, have shown the ineffectiveness of the existing centralized heating system. One of the negative consequences of overheating apartments in multi-story buildings during relatively warm winter periods, subject to the established norm for hot water supply, is that the population is accustomed to high temperatures in residential premises. With the existing system of centralized heating, the consumption of makeup water is usually increased. This is because the normal temperature inside the premises at 18°C seems uncomfortable for consumers, and they are accustomed to interfere with the operation of internal communications. Increased volumes of network water in one separate building inevitably lead to a decrease in the flow of the heat carrier to neighboring buildings, provoking residents to violate the operating regime of the heating system. When the water temperature drops, the process of readjusting the operation of the heating system is accelerated. The consumption of makeup water exceeds the capabilities of heat sources, which forces them to reduce the parameters at the outlets, further limiting the heat energy supplied to consumers. Aim: to analyze the experimental data from two existing Akhmad-Yugnaki’s boiler houses in the Mirzo - Ulugbek districts and show that modular boilers can be used for decentralized heating. Methods: in this article, the analytical method was used as the main method. Results: considering the ineffectiveness of such a mechanism for providing heat, the possibility of switching buildings to closed contours through heat exchangers is being considered, which, as expected, will double the service life of centralized heating systems. The decentralization of the heating sector through the introduction of small and autonomous heating units is also being considered. It is assumed that the use of high-efficiency boilers will reduce the risk of heat supply failures and increase the efficiency of small boiler houses, as well as minimize heat losses during transportation.
Optimization of electric power system modes under conditions of partial uncertainty of initial infor-mation
Relevance: In problems of optimal planning of short-term power system states, partially uncertain load capacity is considered. The partially uncertain nature of active node loads is associated with many factors, which creates certain difficulties. Existing methods for forecasting node loads do not allow for the determination of load schedules for the planning period, taking into account all influencing factors. As a result, optimization results obtained using such load schedules typically contain significant errors, reducing optimization effectiveness. Therefore, given current operating conditions, improving methods and algorithms for optimal planning of short-term power system states under conditions of partial uncertainty of initial data is a pressing issue. Objective: Improving the algorithm for optimizing short-term power system states under conditions of partial uncertainty of initial data. Aim: Improving the algorithm for optimizing short-term power system modes under conditions of partial uncertainty of initial information. Methods: Comparative analysis methods and optimization algorithms are applied taking into account international experience and requirements. Results: Оптимальное планирование краткосрочных режимов в сфере ЭЭС в Узбекистане в условиях четиной неопределённости исходных данных, проверка эффективности предложенного алгоритма на тестовых схемах.
Possibilities of using international solar radiation da-ta in Uzbekistan: approaches for energy and scientific research
Relevance: The stability and efficiency of solar photovoltaic power plants (PV) largely depend on the accuracy of solar radiation data. In Uzbekistan, the lack of long-term and high-precision ground-based observations increases the necessity of employing international satellite- and reanalysis-based models. However, the accuracy of such datasets varies significantly depending on cloudiness, atmospheric conditions, and regional characteristics. Therefore, the verification of international datasets against local meteorological station observations is an urgent scientific and practical task. This approach enhances the accuracy of PV generation forecasting, strengthens the reliability of electricity supply, and reduces investment risks. Aim: The main objective of this study is to improve the accuracy of solar radiation forecasting by comparing and verifying ground-based meteorological station data in Uzbekistan with international datasets (NASA POWER, ERA5, DWD Global, and DWD ICON). On this basis, the reliability of electricity generation forecasts for photovoltaic plants can be ensured, thereby supporting more informed decision-making in planning and operation. Methods: The study utilized data from 22 solar meteorological stations of the Agency of Hydrometeorological Service of the Republic of Uzbekistan for the period 2022–2024. Measurements were carried out at 10-minute intervals, from which hourly and daily values were derived. International data were retrieved from the NASA POWER, ERA5, DWD Global, and DWD ICON databases. To assess accuracy, statistical indicators such as MAE, RMSE, MAPE, and R² were employed. In addition, daily weather conditions were classified into four categories: clear sky, full haze, partly cloudy, and overcast. This classification allowed accounting for atmospheric conditions when evaluating the datasets. Results: The analysis showed that, in hourly verification, the ERA5 dataset demonstrated the lowest error values (MAE ≈ 74.8; RMSE ≈ 95.0), identifying it as the most reliable source. The highest errors were observed in the DWD Global dataset (MAE ≈ 106.4; RMSE ≈ 133.7). For daily cumulative values, ERA5 also produced the highest accuracy (MAE ≈ 298.3; RMSE ≈ 371.8). In cloudy conditions, errors increased sharply across all datasets, indicating the strong impact of cloud cover on forecast accuracy. The results demonstrate that, under Uzbekistan’s conditions, the verification of international datasets with ground-based observations significantly improves the reliability of solar radiation forecasts.
The dependence of the asymmetry regime on the key features of rural networks classification
Relevance: in recent years, the issue of stabilizing electricity supply in rural areas has become particularly important. Due to the seasonal nature of agricultural production, uneven household consumption, and the predominance of single-phase loads in low-voltage networks, unbalanced operating modes of electrical energy have become increasingly evident. Voltage unbalance not only deteriorates the quality indicators of electric power but also leads to transformer overheating, increased losses in electrical equipment, and a reduction in service life. The main classification features of rural power networks—such as voltage level, schematic configuration, type of load, and line length—directly influence the occurrence and development of unbalanced operating conditions. Therefore, in order to ensure a stable electricity supply to rural areas, effectively distribute existing capacities, and deliver high-quality electrical energy to consumers, it is essential to conduct an in-depth study of unbalance processes and analyze them in relation to the network classifications. In such conditions, identifying the sources of unbalance, assessing its consequences, and developing recommendations to mitigate it are of great scientific and practical importance for improving the reliability of rural power supply systems, enhancing power quality, and reducing energy losses. Aim: to analyze the causes and consequences of unbalanced operating modes occurring in rural power supply systems in relation to their main classifications (voltage level, topology, load type, and line length) and to substantiate effective technical and organizational measures aimed at improving the quality of electrical energy supplied to consumers. Methods: comparative analysis methods are used to assess and compare the degree of unbalance in networks of different classifications. Results: in the analysis of load unbalance probability in rural power networks with a voltage level of 0.38 kV, it was determined that instead of using multiple characteristic curves, it is advisable to divide them into two main groups. Based on the analysis results, recommendations are provided for simplifying and improving the accuracy of load unbalance calculations by using two representative characteristic curves.
esearch of the “structure-base” system under dynamic forces
Relevance: during the operation of the water discharge structure into the Birlik Canal, various deformations have occurred in the body and elements of the structure over many years. During operation, as a result of the movement of various types of heavy and light vehicles along the structure under the influence of dynamic loads on the ridge, body, and base of the structure, vertical settlement processes occurred. Especially intensive vertical subsidence was observed in the lower part of the structure's ridge. Dynamic forces led to the formation of cracks in the concrete, vibration of shut-off mechanisms, weakening of fasteners, especially the loss of structural stability. Therefore, it is important to ensure the safety of the structure by checking its resistance to dynamic forces. Aim: research of the stress-strain state during all calculations of loads according to the "structure-foundation" system, ensuring the stability of the structure and the strength of the foundation under the influence of dynamic forces. Methods: the method of finite elements is used when calculating the uneven settlement of a structure. Results: the weakened zone at the base of the spillway is the deformable part in which tangential and normal stresses are determined, which can lead to the destruction of layers located near this zone. When interacting with the fundamental frequency of natural vibrations, horizontal displacements occur synchronously, and their amplitude increases linearly, while the amplitude of vertical vibrations is two times smaller than the amplitude of horizontal vibrations.
Investigation of the Parameters of Various Types of Photovoltaic Modules Integrated with Main Water Canals
Relevance: the efficiency of photovoltaic (PV) modules in converting solar energy into electrical energy in hot climate conditions strongly depends on their surface operating temperature: heating up to 80–95 °C reduces the efficiency by 30–35%. Scientific research has proposed several temperature stabilization methods for PV modules, such as cooling by water, antifreeze, propylene glycol, or air, as well as through thermosiphon or micro-channel heat exchangers. However, such solutions increase the overall cost of the systems. Furthermore, the installation of ground-mounted photovoltaic power plants requires substantial investment for land leasing. Therefore, in hot climate regions, the effective use of existing water surfaces—cheaper than land areas—and the utilization of natural evaporative cooling from water flows are of significant practical and scientific importance. Aim: to determine and analyze the electrophysical and thermal parameters of various types of photovoltaic modules installed above the Oqsuv–Yakkabog main water canal and on land. Methods: to identify the electrophysical parameters of different types of photovoltaic modules, the following methods were applied: measurement of operating parameters and current–voltage (I–V) and voltage–power (V–P) characteristics; infrared imaging and thermographic analysis of hot spots on the optical surfaces of modules; and statistical processing of multiple experimental datasets. Results: the study revealed that installing photovoltaic modules above the water surface reduces their operating temperature due to natural cooling, which decreases temperature-related power losses and enhances performance efficiency. It was found that the output power of monocrystalline and polycrystalline modules placed above the canal exceeds that of similar ground-mounted modules by an average of 5–6%. At the same time, bifacial modules demonstrate higher energy generation on land due to the greater ground albedo compared to water surfaces. The obtained results confirm the high potential of integrating photovoltaic systems with water canals and can be applied in the design and large-scale implementation of such systems within the regional power grid.
Analysis of the quality of briquettes from low-grade brown coals of Kyrgyzstan using regression econo-metric models
Актуальность: Повышение эффективности использования низкосортных угольной мелочи является актуальной задачей для угольной промышленности Кыргызстана, особенно в контексте использования низкокачественных бурых углей. Цель: Целью данного исследования стало прогнозирование прочности полученных брикетов с применением регрессионных эконометрических моделей. В работе использованы экспериментальные данные, полученные при варьировании технологических параметров брикетирования, включая давление, время прессования, температуру, влажность, содержание бентонитовой глины и зольность исходной шихты. Методы: Для выявления факторов, оказывающих наибольшее влияние на прочность брикетов, был проведён корреляционный анализ между результирующим показателем (прочностью) и девятью технологическими переменными. Такие как давление прессования, продолжительность и температуру прессования, влажность шихты, содержание бентонитовой глины, толщину брикета, фракционный состав и длительность естественной сушки. Анализ позволил количественно оценить степень связи между каждым фактором и прочностью брикетов, выявив наиболее значимые из них. Результаты: Нами была построена однофакторная линейная регрессионная модель методом наименьших квадратов, что позволило упростить прогнозные расчёты. Результаты подтверждают надежность полученной модели и её пригодность для практического применения. Таким образом, предложенный нами подход, обеспечивает оптимизации производственного процесса и выбора технологических параметров, направленных на повышение механической прочности топливных брикетов. Полученные зависимости могут быть использованы малыми и средними предприятиями, по производству брикетного топлива из низкосортных углей, для внедрения более устойчивых и экономически обоснованных технологических решений.
Повышение энергоэффективности теплосетей и улучшение экологической составляющей при реализации проекта рекон-струкции централизованного теплоснабжения в г. Бухаре
Relevance: in recent years, due to the energy transition taking place in many countries of the world, energy transition processes are taking place in Uzbekistan. The transition is associated with a turn to green energy and serious problems of diversification of energy sources, development of market relations, digitalization and intellectualization of the energy sector. In such conditions, at all stages of the transition, it is necessary to ensure the reliability of electricity supply to consumers and the provision of electric power systems (EPS) in various modes. Therefore, conducting a study on the use of reliable methods for providing consumers with high-quality electrical power, including when operating wind and solar power plants with unstable modes, is relevant. One of such methods is operational demand response. Aim: analysis and justification of the use of demand management methods for the operational balancing of deficit modes with unstable generation of wind and solar electricity sources. Methods: international experience and methods of comparative analysis of demand management are used. Results: in the green transition and implementation of market relations in the EPS of Uzbekistan with wind and solar installations, it is necessary to use operational demand response methods for effective balancing of the unstable operation of wind and solar installations. Based on the analysis, appropriate proposals were made for the application of demand response methods.
Possibility of Installing Wind Turbines along Highways in Uzbekistan
Relevance: in Uzbekistan, the use of renewable energy sources is of particular relevance. Wind energy plays a key role in ensuring the stability of the power system, reducing dependence on imports, and addressing environmental issues. Installing wind turbines along highways is considered an innovative solution for the country. Aim: the main objective of this paper is to study the feasibility of installing wind turbines along highways in the Kashkadarya region, to calculate their techno-economic efficiency, and to evaluate their environmental significance. Methods: the research applied theoretical analysis, mathematical calculations, graphical methods, and economic evaluation. Statistical wind speed data and vehicle traffic flow modeling were also used to support the calculations. Results: if 10,000 turbines are installed along highways, the total annual energy production will reach approximately 6.2 million kWh. This energy can be used for road lighting, charging electric vehicles, and supplying local networks.
Main equipment used for water coagulation at thermal power plants
Relevance: The current environmental situation in the world inevitably affects the quality of water needed in people's daily lives - both for domestic purposes and for industrial purposes, in particular in thermal power generation. According to calculations, 32-42 cubic meters of water are used to produce one gigawatt of electricity in thermal power plants, for example, from 6 thousand to 10 thousand cubic meters of water are consumed per hour to cool the turbine condenser of one of the power units of a thermal power plant. Aim: Determination of the dependence of the coagulant dose on the composition of water using clarifiers designed by SNII-2 in water treatment at thermal power plants and shopping centers. Methods: At thermal power plants, water purification to the required quality, depending on the profile of the enterprise, is carried out using mechanical, chemical, physicochemical, biological and thermal treatment methods. Results: In our experiment, if FeSO4 salt is used as a coagulant, then to bring the pH of the water to an alkaline environment, using the formula Di = Dk – Ium + Iq, Table 1 shows how to obtain the dose of coagulant depending on the amount of organic and suspended matter in the water without adding a flocculant to the water.
Strategies to reduce energy consumption and sus-tainability solutions of generative artificial intelligence
Relevance: In the modern world, along with the unprecedented development of artificial intelligence (AI) technologies and their deep penetration into our daily lives, the negative consequences of this development are also becoming increasingly evident. In particular, the energy consumption of AI-based data centers is increasing sharply, becoming one of the most pressing global issues. According to reliable forecasts from Deloitte, by 2030, the electricity consumption of global data centers is expected to double from the current figure, reaching 1065 TWh. This growth will not only put serious pressure on the existing energy supply infrastructure and lead to rising energy prices, but will also accelerate global climate change through increased carbon emissions. In order to mitigate the negative impact of this intense energy demand on the environment and the economy, improving the energy efficiency and ensuring sustainability of generative artificial intelligence (GAI) systems is one of the most pressing tasks today. Instead of a race to create large, parameter-rich models, there is a need to develop smaller, more efficient, and more environmentally sustainable AI models. Without innovation and optimization measures, data center energy consumption will continue to increase, directly contributing to global climate change and energy scarcity. Finding a balance between the advancement of AI and environmental sustainability is a scientific and technological challenge of great importance to today's and future generations. Aim: Show the reasons for the sharp increase in energy consumption and data processing in connection with the rapid development of artificial intelligence (especially generative artificial intelligence), pay attention to ecological and economic consequences in the future, and also emphasize the need for increased energy efficiency, the use of ecologically clean energy sources and introduction innovative technological solutions to these problems. Methods: The research methodology of this paper is based on a comprehensive analysis of the energy consumption problem of generative artificial intelligence (GAI) technologies, a comprehensive review of the existing literature, and a synthesis of industry reports and expert forecasts. Using a descriptive-analytical approach, the study assesses the future energy demand trends of GAI and proposes effective solutions to this problem. Results: Based on the information provided in the article, the relationship between the development of artificial intelligence and energy consumption is analyzed, and problems in this regard and ways to solve them are indicated.
Analysis of experimental test results of a mobile photovoltaic-thermal device
Relevance: in recent years, rapid population growth has significantly increased the demand for energy devices utilizing renewable energy sources, particularly solar energy. Currently, fossil fuels and other non-renewable resources are rapidly depleting due to high energy consumption. Furthermore, the excessive use of primary energy sources has led to serious environmental damages, including climate change, global warming, ozone layer depletion, and more. Therefore, finding long-term energy sources is one of the main challenges for scientists worldwide. Solar energy technologies offer a convenient way to rationally utilize alternative energy sources in heating systems, air conditioning, and electricity generation. Today, solar energy is one of the most important and renewable energy sources and one of the most effective types of its utilization. Photovoltaic solar devices stand out from traditional energy sources due to their reliability, stability, and portability. These devices are rapidly being implemented in many areas; while they can be integrated into traditional energy grids in some regions, their use is more suitable in decentralized areas where traditional energy grids are unavailable. Aim: development, testing, and analysis of experimental results of a mobile photovoltaic-thermal device designed for energy consumers located far from centralized energy supply, equipped with an autonomous energy supply system, and simultaneously providing both electricity and hot water. Methods: the research work, based on experimental data, relies on data obtained from testing a water-based module surface cooling system in a mobile photovoltaic-thermal device. Results: It has been experimentally determined that the guaranteed supply of electricity and hot water to populations and social facilities located far from the main power supply can be achieved through a mobile photovoltaic-thermal (PV-T) device. Based on the fact that the efficiency of a solar-powered PV-T device primarily depends on the intensity of incident solar radiation and is inversely proportional to the operating temperature of the solar cells, an increase in the power output of the module was achieved by applying water-based cooling technology.
Modeling the self-excitation process of a conventional non-salinity pole synchronous generator using the Matlab Simulink model
Relevance: Self-excitation is an electromagnetic instability characterized by a spontaneous increase in voltage and current (U and I) in system elements and generator windings. A necessary condition for self-excitation is the presence of a connected capacitance in the stator circuit, creating an oscillatory circuit with the machine's inductive reactance. Since the specific and mutual resistances of the machine windings change over time during rotor rotation, conditions may arise in which electrical oscillations in the circuit do not attenuate, but rather increase. This is called self-excitation. The self-excitation process of a synchronous generator is considered a negative phenomenon, since voltages and currents can be very high and, most importantly, impossible to control. Aim: To model and analyze the self-excitation process of a conventional non-salient-pole synchronous generator using the MatLab Simulink model. Methods: The study utilized the theory of electromagnetic transient processes in synchronous generators, mathematical approximation, the Runge-Kutta method for solving differential equations, modeling of self-excitation processes in MatLab Simulink, and mathematical statistical methods for comparing and processing the obtained results. Results: The results of modeling the self-excitation process of a traditional synchronous generator with unstable poles are presented using the Matlab Simulink model.
Intelligent phase symmetry algorithms in low-voltage networks with integrating PV panels
Relevance: The development of distributed generation based on photovoltaic systems (PV) is causing new technical challenges in low-voltage electric networks. One of the key problems is the phase asymmetry caused by the uneven connection of single-phase PV. The asymmetry of voltages and currents leads to a deterioration in the quality of electricity, increased losses, overload of the neutral wire and a decrease in the reliability of the power supply. In these conditions, the task of developing effective phase symmetry methods that ensure the stable operation of the network and the integration of renewable energy becomes particularly relevant. One of the promising approaches is the use of intelligent control systems, in particular, fuzzy logic (FLC), for adaptive phase control and control of FES operating modes. Aim: Development of an intelligent method for controlling phase symmetry in low-voltage networks with distributed solar integratsion based on the use of fuzzy logic (FLC) in order to minimize neutral current, increase phase symmetry and reduce losses in the system. Methods: In the course of the research, MATLAB/Simulink modeling methods, the theory of indefinite sets, as well as phase symmetry algorithms were applied. A fuzzy logic (FLC) based controller has been developed. Results: The existing models and methods of complex optimization of short-term modes of electric power systems based on decomposition are improved. The results of the study of its effectiveness are presented using the example of an 8-node test scheme of the EPS.
Introducing of computer simulators for studying the topic of free convection in the discipline of heat and mass transfer
Relevance: Higher education instructors are introducing various digital/computer-based teaching units for several reasons. First, to increase students' interest in computer technology and their ability to use various products. Second, to increase motivation, as many simulators are essentially quests. Third, using the first and second methods, you can improve your problem-solving skills across topics. And, of course, it's impossible to require all students to complete all assignments at the same pace across all subjects. Computer-based simulators offer the opportunity to choose your own learning path. Aim: to introduce computer simulators on the topic of Free Convection in the discipline of Heat and Mass Transfer into the educational process and to increase motivation, increase interest and level the level of problem solving for students studying this material. Methods: Development and use of a computer simulator for solving problems in the discipline Heat and Mass Transfer on the topic of Free Convection. Results: The testing showed the didactic suitability of the simulator and the effectiveness of its use in the educational process; the second scenario aroused the greatest interest. To practice problem-solving skills and improve them, these simulators were created so that weaker students, by solving several problems on one topic, could improve their level of knowledge and problem-solving skills.
Assessment of Corona Losses Impact in High Voltage Overhead Transmission Lines
Relevance: in recent years, the total power losses in high-voltage overhead transmission lines have significantly increased, leading to various disturbances in the operating modes of electrical networks. Furthermore, since the share of corona-related losses in the overall power dissipation is relatively high, the development of optimal operating regimes and reduction methods has become a matter of great importance. The corona phenomenon decreases the reliability of the insulation system, causes degradation of insulation materials, and may lead to dielectric breakdown, resulting in the complete failure of the system. The significance of this research lies in the fact that the parameters characteristic of the corona discharge process in high-voltage transmission lines have a negative impact on electrical power losses. This necessitates a comprehensive analysis of these parameters and the development of effective measures aimed at minimizing their influence. Aim: system analysis and optimization of total power losses caused by corona discharge in high-voltage overhead transmission lines. Methods: methods of comparative analysis of software, mathematical modeling, and algorithmization are used. Results: the generation of the visible onset voltage of corona discharge represents the voltage level at which visually observable signs of corona appear on transmission lines. This parameter provides important information about the insulation quality of the system and the uniformity of the electric field. These interrelations are of significant importance when assessing the reliability of insulation and the energy efficiency of power transmission systems.
Optimization of electric power system modes under conditions of the probabilistic nature of the initial information
Relevance: In problems of optimal planning of short-term states of electric power systems, the initial probabilistic quantities are node loads and the active resistances of network elements. The probabilistic nature of network resistances is related to the ambient temperature. Therefore, based on the weather forecast for the planning period, they are calculated by making appropriate adjustments to the resistances of the elements. The probabilistic nature of active node loads is associated with many factors, which creates certain difficulties. Existing methods for forecasting node loads do not allow for the determination of their load schedules for the planning period, taking into account all influencing factors. As a result, optimization results obtained using such load schedules typically contain significant errors, reducing the effectiveness of optimization. Therefore, improving methods and algorithms for optimal planning of short-term states of power system operating modes, taking into account current operating conditions, is a pressing issue. Aim: Improving the algorithm for optimizing the short-term mode of the power system under conditions of probabilistic initial information. Methods: Comparative analysis methods and optimization algorithms are applied taking into account international experience and requirements. Results: Optimal planning of short-term EPS situations in Uzbekistan under probabilistic initial data conditions, testing the effectiveness of the proposed algorithm on test circuits.
Modeling the dynamics of power circuits using a generalized state space model
Relevance: one of the pressing issues in the development of modern energy is the development of new models and the modernization of existing high-efficiency power plants. The evolution of modern power plants is characterized by a steady trend toward expanding their scope of application and increasing complexity. Power plants have evolved from systems with simple analog regulators to modern computer-controlled systems, which, as a result, offer new capabilities, including flexible control algorithms, remote control, and more. Requirements for the functionality and reliability of such plants have increased significantly, improving their dynamic characteristics, developing control and diagnostic subsystems, and expanding and complicating control functions using new intelligent technologies. One way to meet these requirements is the further development of methods and tools for mathematical and computer modeling of power plants themselves and their components, as well as their integration into design, control, monitoring, and diagnostic processes. Aim: analysis and justification of the use of a generalized state space model for modeling power circuits. Methods: of mathematical and computer modeling and elements of automatic control theory. Results: using a generalized state space model to simulate power circuit dynamics reduces the number of modeling equations and uses a single algorithm to solve a set of differential-algebraic equations. The results demonstrated the feasibility and effectiveness of this approach.
Isitish tizimidagi issiqlik energiyasini optimal uzatish uchun issiqlik tarmogʻini ratsionalizatsiya qilish
Relevance: an innovative method for calculating optimal heat supply radii allows for the technical and economic justification of efficient heat supply zones. The method is based on calculations to determine the cost of thermal energy and capital expenditures. This method minimizes the use of empirical relationships in calculations and allows for the determination of a numerical value for the effective heat supply radius. The results have been validated, and the method can be used in developing heat supply schemes for populated areas. Aim: development of a methodology that minimizes the use of empirical dependencies in calculations and finds the numerical value of the radius of effective heat supply. Methods: analytical method is used to determine the radii of efficient heat supply. The calculation algorithm is based on an analysis of the integral equation linking capital expenditures on heat networks and the heat load values of consumers. Results: fairly simple and precise formulas for the method of calculating rational radii for the economic justification of the zone of efficient heat supply have been obtained.
Improving the efficiency of electrical networks using an intelligent measuring module
Relevance: Modern electrical networks are experiencing increased loads, more complex operating modes, and higher requirements for reliability and quality of power supply. Traditional control and management methods no longer provide the necessary speed and accuracy. In these conditions, the introduction of smart metering modules is becoming a key direction in the development of the electric power industry. They enable high-precision data to be obtained in real time, improve network efficiency, identify deviations in a timely manner and reduce operating costs. Therefore, analysing ways to improve the efficiency of electrical networks using smart metering solutions is a pressing task and has significant practical value. Aim: analyse the possibilities for improving the efficiency of electrical networks through the introduction of an intelligent metering module and determine its impact on control accuracy, operational reliability and optimisation of power supply modes. Methods: utilised a systematic analytical approach to assess the condition and structure of modern electrical networks, a technical and economic analysis to determine the effectiveness of implementing an intelligent measuring module, a comparative functional analysis of traditional and intelligent measuring devices, methods of mathematical and simulation modelling to reproduce network operating modes and assess the module's impact on its stability, as well as statistical data processing and correlation-regression analysis to interpret the results and identify key patterns. Results: The study found that the introduction of an intelligent measuring module improves the accuracy of electrical network parameter monitoring, ensures rapid detection of deviations, and reduces the likelihood of emergency modes. Modelling showed an improvement in the quality of electricity transmission, increased network stability, and reduced power losses. A comparative analysis confirmed the advantage of the smart module over traditional measuring devices due to its higher information content, adaptability, and ability to integrate into modern monitoring and control systems.
Features of designing small hydroelectric power plants in mountains
Relevance. Currently, the share of renewable energy sources in the Republic of Uzbekistan is sharply increasing, especially small hydroelectric power plants (MGES) are an important element of renewable energy, and their use in mountainous and foothill areas allows for the efficient use of natural resources. These regions of Uzbekistan have great opportunities due to their elevation and abundance of rivers. However, the design and construction of hydraulic structures in such areas has many specific complexities related to natural, technical, ecological, and economic conditions. Despite the high energy potential of small rivers, it has practically not been developed. This confirms the relevance of developing effective solutions for its use. Aim: The article examines the experience of designing small hydroelectric power stations (SHPS) in mountainous and foothill regions that can be used for the development of small hydropower in Uzbekistan. The article presents an analysis of hydrological, climatic, and geological conditions influencing the selection of placement schemes and technological solutions. The location, type, equipment, and choice of the hydraulic unit's derivation route are justified. The results of the work can be used in the development of projects for small hydropower plants. Methods: To effectively utilize pressure, it is recommended to use a combined pressure-free-pressure derivation scheme with open channels and a pressure basin. At pressures above 80 m, it is advisable to use bucket turbines, and at pressures of 20-80 m, radial-axial turbines. To increase reliability during seismic impacts, it is recommended to provide anchor support for the main hydraulic structures to rocky foundations. Results: The choice of bucket or radial-axial turbines depending on the pressure ensures high energy efficiency and reliable operation of stations under variable water flow conditions. Small hydroelectric power plants (SHPPs) are an effective and environmentally sustainable solution for energy supply in the mountainous and foothill regions of Uzbekistan.
Study of the Influence of Steel Saturation on the Spatial Harmonic Fields of the Stator in the Machine Air Gap
Relevance: the performance of alternating current electrical machines largely depends on the characteristics of the magnetic field in the air gap, including its spectral composition. One of the factors influencing the field distribution is the magnetic core steel saturation. Although this effect has previously been studied in the context of integral machine parameters, its influence on the spatial harmonics of the field—especially in machines with a fractional number of slots per pole per phase—remains insufficiently explored. Considering magnetic saturation in harmonic analysis makes it possible to refine calculations of torque pulsations, noise levels, and heating. Therefore, the development of models that reflect the influence of saturation on the magnetic field spectrum is of great interest for more accurate design and simulation of electrical machines. Aim: to investigate the influence of magnetic core steel saturation on the spatial harmonic components of the magnetic field in the air gap of alternating current electrical machines, taking into account the winding configuration and magnetic material properties. Methods this study employs analytical and numerical modeling methods to analyze the distribution of the magnetic field in the air gap of alternating current electrical machines, considering the saturation of the stator and rotor core steel sections. Results: it has been established that saturation of the stator and rotor steel significantly reduces the amplitude of the fundamental harmonic component of the magnetic field in the air gap. When the equivalent magnetic permeability decreases from μ = 4000 to μ = 100, the fundamental harmonic amplitude drops by a factor of 1.5.
Possibilities of Heating Swimming Pool Water Using Solar Energy in the Climate Conditions of Uzbekistan: A Scientific Analysis
Relevance: Energy-efficient heating of swimming pool water is becoming an important task in Uzbekistan, as energy resource prices continue to rise year by year, creating a significant economic burden for the sector. The country’s high solar radiation (around 300 sunny days per year) expands the possibilities of using solar energy in this field and calls for alternative solutions compared to conventional water-heating methods. Maintaining stable water temperature in children’s and school swimming pools is extremely important for health and safety. Therefore, it is essential to conduct a comprehensive analysis of the integration of construction materials, thermal insulation, and solar heating systems. Aim: The main objective of the study is to assess the feasibility of efficient water heating in open and indoor children’s and educational swimming pools using solar energy under the climate conditions of Uzbekistan, to reduce energy consumption through the integration of passive and active methods, and to identify optimal technical and economic solutions. Methods: a) Structural and technical analysis: Thermal conductivity and service life of pool materials (fiberglass, PVC, concrete, epoxy resin) were compared; FINA norms and EN 15288, and ASHRAE standards for children’s and educational pools were analyzed. b) Energy modeling: Heat demand depending on the water level in the pool; evaluation of the impact of passive measures (covering, wind-shield barrier, insulation); c) calculation of solar heating systems: Assessment of the efficiency of applying solar collectors for water heating depending on seasonal solar radiation; d) Environmental and economic assessment: Calculation of primary energy savings and reduction of CO₂ emissions achieved through the use of hybrid water-heating systems in swimming pools. Results: - conclusions on the optimization of structural design solutions for swimming pools using energy-efficient materials. - The effect of passive heating. - evaluation of the efficiency of passive water-heating methods for swimming pools. - assessment of swimming pool solar water-heating systems using solar collectors. - hybrid water-heating system for swimming pools (passive + solar water heating) is suggested. - practical recommendations for children's swimming pools.
Energy saving based on control of static and dynamic operating modes of asynchronous motors of feed grinding devices
Relevance: frequency control is saving because it improves the efficiency of the induction motor by rectifying the speed of the induction motor and reduces power loss. It is shown how to start and control the equipment for grinding feed using a frequency converter, which is installed between the machine and the motor and controls the speed of the motor. Previously, front gearboxes were used to change the speed of the electric motor, which, in turn, led to various difficulties. If it is necessary to reduce or increase the number of revolutions of the electric motor due to the peculiarities of the production technology, the use of additional mechanisms in the electric drive, in turn, led to an increase in the power of the electric motor. With the help of frequency converters, the speed can be directly controlled by changing the frequency of the electric motor. One of the advantages of this method is that since current and torque are closely related, the frequency converter can reduce the starting current when starting the motor. When starting, the motor starts smoothly, which saves energy during startup. Aim: justification of energy savings due to control of static and dynamic modes of asynchronous motor of feed grinding devices. Methods: methods of frequency control, experimental and comparative analysis were used. Results: frequency control has enabled a 17% saving in electricity consumption, adjustment of the speed of the asynchronous motor, smooth start and stop of the electric drive, and reduction of power waste of the asynchronous motor.
Ensuring uniform distribution of heat flow in the process of ultrasonic-convective drying
Relevance: optimization of drying processes ensures energy efficiency. Nowadays, this indicator plays a crucial role. This article analyzes the temperature distribution in a drying unit for red beetroot. The analysis was carried out on several varieties of red beetroot. Uniform distribution of the supplied temperature throughout the drying chamber ensures stable process conditions. During the drying process, the initial moisture content of the sample was 86–89%, while the final moisture content reached 15–17%. In these studies, samples with a thickness of 7–8 mm were subjected to ultrasonic treatment at a frequency of 20–30 kHz. Aim: to determine the drying regimes and parameters of red beetroot, as well as to analyze and justify the use of ultrasound during the drying process. Methods: comparative analysis methods of international practices were applied. Results: it was found that at a chamber temperature of 55 °C, the optimal drying regime was achieved. In addition, our study analyzed the effect of ultrasound, which was found to have a positive impact on accelerating diffusion and improving the distribution of heat during the drying process.
Development of Wind Energy in Uzbekistan as a Basis for the Green Economy
Relevance: The development of renewable energy sources in Uzbekistan is a strategic task amid growing electricity consumption and the need to reduce carbon emissions. Wind energy has significant potential — estimates suggest the country’s total wind resources exceed 520 GW, several times higher than its national demand. Large wind farms in Karakalpakstan, Navoi, and Bukhara will diversify the energy mix, reduce the load on gas-fired power plants, and strengthen energy security. Aim: To assess the significance of current and future wind energy projects in Uzbekistan for increasing the share of renewable sources, ensuring energy security, and implementing the “green economy” strategy. Methods: Analysis of project documentation and statistics from the Ministry of Energy of Uzbekistan; comparison of wind farm capacities and output with international trends (IRENA, IEA); evaluation of environmental and economic impacts (reduction of CO₂ emissions, gas savings, job creation). Results: It has been shown that by 2030 Uzbekistan plans to commission more than 3 GW of wind power capacity (Navoi – 500 MW, Bukhara – 1000 MW, Karakalpakstan – up to 1500 MW and others). These projects will generate tens of billions of kWh annually, save over 3 billion m³ of natural gas, and reduce CO₂ emissions by up to 5 million tons. Large-scale deployment of wind energy supports the implementation of the “Green Economy Transition Strategy” and aligns with global renewable energy trends.
Modern Technologies for Monitoring Overhead Transmission Lines
Relevance: in recent years, due to the energy transition taking place in many countries of the world, energy transition processes are taking place in Uzbekistan. The transition is associated with a turn to green energy and serious problems of diversification of energy sources, development of market relations, digitalization and intellectualization of the energy sector. In such conditions, at all stages of the transition, it is necessary to ensure the reliability of electricity supply to consumers and the provision of electric power systems (EPS) in various modes. Therefore, conducting a study on the use of reliable methods for providing consumers with high-quality electrical power, including when operating wind and solar power plants with unstable modes, is relevant. One of such methods is operational demand response. Aim: Efficient management of power networks, increasing energy transmission efficiency, and reducing maintenance costs by monitoring the temperature, mechanical tension, sag, icing, and electrical parameters of OHTL conductors. Methods: Telemetric monitoring of electrical and mechanical parameters of conductors; Utilization of modern monitoring systems such as CAT-1 and OTLM; Application of sensors, strain gauges, accelerometers, and meteorological stations; Data transmission via wireless communication channels (GSM, GPRS, ZigBee, xBee) and processing in SCADA systems. Results: Power transmission efficiency increases by up to 15–30%; Failure detection and fault localization become faster, reducing maintenance costs; Network reliability improves by identifying critical conductor states, icing, and resonance phenomena.
Organizational and technical measures for ensuring electrical safety in the transport sector
Relevance: ensuring electrical safety in transport enterprises, especially in railway systems that utilize high-voltage electrical equipment, is a critically important issue. Increasing voltages, the expansion of electrical devices, and constant operational loads raise the risk of electric shock. Failure to follow safety protocols can lead to serious consequences, including injuries, fires, and accidents. Today’s conditions require the implementation of effective protection systems, technical maintenance, and monitoring. The relevance of this topic lies in the need for a systematic approach to reducing risks and enhancing a culture of workplace safety in the transport sector. Aim: to study and justify effective measures for ensuring electrical safety at railway transport enterprises. Methods: analysis of standards, comparative review, modeling, risk assessment, and technical evaluation. Results: analysis confirmed grounding, neutral connection, and RCDs are most effective. Operational errors were identified. Regular safety inspections and updated protective measures significantly reduce electric shock risk in transport enterprises.
Peculiarities of Integrating Renewable Energy Sources into the Power System
Relevance: the integration of renewable energy sources (RES) into the power system of Uzbekistan is of strategic importance for the country's development. The integration of RES requires a comprehensive modernization of infrastructure, including the development of "Smart Grids." This stimulates the adoption of modern management technologies, energy storage systems, and the digitalization of monitoring, thereby increasing the overall efficiency of the energy sector. Thus, the integration of RES is driven not only by technical challenges but also by strategic objectives in the fields of ecology, energy security, economic development, and infrastructure modernization. Their successful resolution is the key to a prosperous future for the country. Aim: to analyze the influence of integrating renewable energy sources on power flows and power quality in the energy system. Based on this analysis, the goal is to evaluate the capabilities and limitations of specialized software. Methods: the following methods were used: analysis of scientific and technical literature, international standards (IEEE, IEC), and existing mathematical approaches and software tools. Results: the analysis of scientific and technical literature allowed for the systematization and generalization of the key challenges that arise when integrating renewable energy sources (RES) into modern power systems. The results obtained reflect the general consensus of the scientific community on this issue. Studies show that for a detailed analysis of RES integration, complex software tools such as DIGSILENT Power Factory, ETAP, and PSS/E are used. There is also a growing trend toward using co-simulation (for example, MATLAB/Simulink), which allows for more accurate modeling and the development of new control algorithms.
The role of innovative software in increasing the efficiency of energy systems
Relevance: increasing efficiency in modern energy systems requires not only technical, but also digital solutions. In particular, there is a sharp increase in the need to introduce accurate, sustainable, and intelligent tools for identifying, analyzing, and forecasting electricity losses. In this process, innovative software tools that perform tasks such as real-time data processing, automatic selection of forecasting models, and working with cluster and anomalous data are of great importance. This is especially ensured by increasing energy efficiency in low-voltage networks, such as 0.4 kV distribution networks, and implementing precise monitoring and forecasting mechanisms. In such conditions, information systems with intelligent functions, created in modular and adaptive architecture, not only increase the efficiency of maintenance but also ensure the objectivity and speed of the decision-making process. Aim: development of innovative software that serves to automate the processes of analysis and forecasting of electricity losses in energy networks, scientific assessment of the effectiveness of the system based on its modular architecture, functional capabilities, and integrated forecasting models. Methods: in the modeling process, a comprehensive approach was applied, based on the integration of clustering, specialized neural networks for forecasting, and classical statistical methods that take into account the structure of data. Results: An information system for forecasting electricity losses - ISFEL in 0.4 kV distribution networks has been developed. Polynomial regression, ARIMA, GMDH, MLP, and hybrid forecasting methods were integrated into the system. This system is equipped with adaptive mechanisms that take into account the complexity and variability of the data structure, ensuring high accuracy and adaptability to operating conditions through the appropriate selection of a forecast model, visual analysis of results, and reduction of the influence of the human factor.
Using digital models to optimise energy systems
Relevance: Currently, the use of digital systems for process optimisation and digital transformation is growing day by day, and the implementation of digital transformation in the energy sector is the most relevant area of focus. The main objective of this study is to summarise existing international experience based on the best practical results of current international practices in the field of digital models, which allow us to study the internal and external factors that influence the efficiency of the industry. The article pays particular attention to analysing the problems and advantages of using technology to solve regional energy problems, as well as assessing the impact of digitalisation processes on economic indicators and the prospects for further expansion of the use of digital twins in energy companies. The work was based on an assessment of data on the implementation of digital twins by energy companies in neighbouring and distant foreign countries, which have demonstrated the high effectiveness of this technology in solving regional problems by increasing the productivity and reliability of distribution networks. It was noted that companies where digital twins are involved in projects have high results in terms of profit growth and profitability, which confirms the possibility of further implementation of innovative technologies. Aim: Using modern tech to tackle regional energy challenges, as well as assessing how digitalisation affects economic indicators and the prospects for further expanding the use of digital twins in energy companies. Methods: When considering issues related to the digitalisation of systems, modern theories and methods of mathematical programming were used to model the dynamic processes of the system, and appropriate algorithms were developed for the effective implementation of digital transformations in the energy sector. The work was based on an assessment of data on the implementation of digital twins by energy companies in neighbouring and distant foreign countries, which have demonstrated the high effectiveness of this technology in solving regional problems by increasing the productivity and reliability of distribution networks. Results: An analysis of the experience of using digital twins in the energy sector in neighbouring and distant foreign countries has shown that digital transformation has undergone significant development both in the field of electricity generation and in the operation of transmission and distribution networks.
Heat transfer and air-flow circulation processes in a solar water-heating polygeneration system
Relevance: In the context of the rapid development of solar water-heating systems as a stable and environmentally safe source of energy supply, increasing their thermal efficiency and ensuring uninterrupted heat delivery to end-users are becoming particularly important. Heat transfer processes—especially the dependence of convective heat exchange on the Nusselt number-represent key factors that determine the operational performance of such systems. Although numerous studies on solar water heaters exist, the fundamental physical mechanisms of heat transfer, the influence of flow regimes on temperature distribution, and the relationship between flow behavior and the thermal output at the collector outlet have not been sufficiently explored. In particular, more accurate and reliable correlations are needed for real operating conditions such as changes in mass flow rate, absorber geometry, thermo-physical properties of the working fluid, and fluctuations in solar irradiance. From this perspective, the present study is highly relevant as it proposes new methodological approaches for characterizing heat-exchange processes, improves the accuracy of analytical and empirical models, and enables optimization of structural solutions in solar water-heating systems through advanced numerical simulations. The obtained results are of significant practical value for ensuring thermal stability, reducing energy losses, and enhancing the overall efficiency of solar-thermal systems. Aim: The primary aim of this study is to conduct an in-depth analysis of the heat-transfer processes and the natural and forced circulation phenomena occurring in solar water-heating polygeneration systems, to determine their thermo-hydraulic characteristics, and to develop new scientific approaches aimed at improving system performance. Special emphasis is placed on examining the formation of natural thermosiphon flow from the solar collector to the storage tank, temperature-driven water stratification, the development of pressure differences, and the dependence of circulation intensity on the Nusselt number, Reynolds number, and density variations of the working fluid. Methods: The heat-transfer mechanisms and the natural and forced circulation of liquid and air flows in the solar water-heating polygeneration system were investigated through theoretical analysis, computational modelling, and numerical simulation. Initially, natural thermosiphon circulation was analyzed based on water heating in the collector, density reduction, downward movement of cooler water, and vertical stratification within the storage tank. The pressure difference driving circulation was determined as a function of the height difference between the collector and tank and the density variation of the fluid. Convective heat transfer was evaluated using correlations based on the Nusselt, Reynolds, and Prandtl numbers. Under turbulent flow conditions, heat-transfer enhancement in the absorber channels was achieved through the application of surface roughness elements and turbulence-promoting devices. Thermo-hydraulic performance was assessed through the ratio of pressure losses to the heat-transfer coefficient. Experimental measurements were compared with CFD simulations performed in ANSYS Fluent to validate the theoretical models. Results: This study investigated heat-transfer and circulation processes in a solar water-heating polygeneration system using theoretical analysis, numerical modelling, and simulation tools. Natural circulation was shown to arise from the reduction of water density during heating, downward movement of colder water, and stratification within the storage tank. The pressure difference driving the circulation was evaluated from the height difference and density change of the working fluid. Heat-transfer processes were quantified using Nusselt-, Reynolds-, and Prandtl-number-based correlations. Under turbulent conditions, heat-transfer enhancement was achieved using surface roughness and turbulators inside the absorber channels. Thermo-hydraulic performance was evaluated through the balance between pressure drop and heat-transfer coefficient. Experimental observations showed good agreement with CFD (ANSYS Fluent) simulation results, confirming the accuracy of the proposed models.
Investigation of the clay products drying process using composite polyethylene films based on functional ceramics
Relevance: currently, the sustainable development of the construction materials manufacturing industry is directly linked to strategic issues such as resource conservation, product quality improvement, and ensuring environmental safety. Traditional thermal processing and drying technologies are often characterized by high energy consumption and cause environmental problems that negatively affect the surrounding environment. In particular, in the process of drying clay products, technological limitations, such as high-temperature regimes and insufficient humidity control, lead to a reduction in the strength of the finished product (raw brick or porcelain items), the formation of cracks and the deterioration of their appearance. This, in turn, results in significant losses at the final product manufacturing stage. Given the above, the implementation of environmentally clean and highly efficient alternative drying technologies, moving away from traditional energy sources, is an urgent scientific and practical task for this industry. Aim: the goal is to practically substantiate the energetic and operational dynamics of solar dryers using polyethylene-ceramic composite materials to determine optimal drying regimes for clay products. This will allow for the minimization of defects, such as cracks in the products and dew formation under the transparent cover of the setup, thereby increasing overall energy efficiency and quality indicators. Methods: The present study is aimed at evaluating the performance of solar dryers utilizing both functional ceramic-based composite polyethylene film and conventional polyethylene films to enhance the efficiency of the clay product drying process. The research encompassed a series of experimental and measurement procedures during the drying of clay products with a thickness of 5 cm. Results: during the drying process under the conventional film, a high degree of dew (condensate) formation was observed (Figure 5b). In contrast, under the composite film, dew formation was practically not detected (Figure 5a). The appearance of dew leads to the accumulation of moisture on the product surface and slows down the drying process, which, in turn, results in the deterioration of product quality. Furthermore, at the final stage of drying, the clay product dried under the conventional film was found to have significantly more cracks compared to the product dried under the composite film. This indicates that the composite film enabled more uniform drying of the clay. This result serves as a fundamental basis for the creation of new types of constructions.
Green Building Certification in Uzbekistan: Current Status and Development Prospects
Relevance: In Uzbekistan, buildings-particularly in the social sector—remain major consumers of energy. As the country moves toward a green economy, the need to introduce a national building green certification system becomes increasingly important. Such a system can reduce energy consumption, lower CO₂ emissions and improve the operational performance of buildings. Aim: to identify opportunities for developing a national green building certification system in Uzbekistan based on the analysis of international experience, national regulations and existing pilot projects. Methods: comparative analysis of international certification systems (LEED, BREEAM, EDGE), review of Uzbekistan’s regulatory documents, and analysis of state programs and pilot project outcomes. Results: Although the regulatory foundation has been established, practical implementation remains limited. The effectiveness of green buildings in reducing energy consumption and emissions is confirmed. Key recommendations include institutionalizing certification, providing incentives for developers, integrating certification with energy passports and expanding pilot projects.