ISSN 2223-0858 (Online) Subject: theoretical and applied sciences, technology and industry in the field of energy and automation Year established: 2009 Founder and publisher: National University of Life and Environmental Sciences of Ukraine Publisher registration number (EDRPOU): 00493706 Publisher's ROR: https://ror.org/0441cbj57 DOI prefix: 10.31548 Published 6 time a year Media identifier R40-02287. The National Council of Television and Radio Broadcasting of Ukraine Decision No. 1796 of 21 December 2023, protocol No. 31 The journal is included in category “B” of the List of scientific professional publications of Ukraine (Order of the Ministry of Education and Science of Ukraine No. 928 of 11 June 2026). Cluster: Safe, clean energy and energy efficiency. Specialty: G3 electrical engineering; G4 energy production. Languages of the publication: Ukrainian, English Address: Heroiv Oborony st., 12, Kyiv-03041, Ukraine Phone: +38 044 527 85 22
Національний університет біоресурсів і природокористування України
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Analysis of statistical methods modeling of the monitoring four-wire networks electricity quality indicators results for estimating additional losses
Deviations in electricity quality indicators in the conditions of production processes at modern industrial facilities with branched internal four-wire networks lead to significant electricity losses. This study is a continuation of a comprehensive analysis of power quality problems in four-wire networks by systematizing methods of statistical and mathematical modeling to improve the technical and economic performance of internal networks under conditions of deviations, flickers and voltage dips, harmonic distortions, phase asymmetry, significant reactive power flows, taking into account compliance with the standards IEC 61000-4-30, EN 50160, IEEE 519 based on practical experience in implementing modern digital analyzers of network parameters. Operational management of energy consumption at such facilities is associated with the need to create and implement modern measuring complexes for monitoring network parameters in real time. As practice shows, a significant and priority integral indicator is supply voltage fluctuations. Given the high complexity of building technical systems for regulating electricity quality indicators with operational control (dispatching), eliminating or reducing such negative phenomena in real time is quite difficult, and sometimes impossible at a sufficient technical level. As of today, operators of such systems can be helped by subject-oriented highly specialized intelligent expert systems, the information and analytical basis of which is modern mathematical and statistical modeling methods. The paper presents a review of methods and algorithms for statistical modeling of deviations from normalized values ​​of electricity quality indicators using the example of the supply voltage of a four-wire network of a local facility, which are proposed to be used as mathematical tools for quantitatively assessing the impact of voltage deviations from normalized values ​​for measuring inactive capacities of a three-phase power supply system based on operations with currents and voltages represented in the αβ coordinate system. The known method for determining the scalar capacities of a three-phase four-wire power system requires the formation of input data, which can be obtained experimentally, forming a database of deviations of power quality indicators in real time. The experiment showed the adequacy of the calculated and experimental data. The change in the nature of the load with the deviation of the supply voltage from the normalized values ​​\u200b\u200bsignificantly affects the integral power losses, which can be used for decision-making in energy management systems of enterprises. Recieved: 02.02.2026. Recieved: 26.05.2026. Accepted: 22.06.2026
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Experimental study of thermoelectric systems for obtaining water from atmospheric air
In the near future, water will become the most valuable resource on the planet, and this trend will only increase in the future. This situation leads to catastrophic consequences and may also occur in Ukraine in the near future. Atmospheric air appears as a promising, renewable and widespread source of moisture. It is believed that the Earth's atmosphere simultaneously contains about 12.9∙103 km³ of water. Systems for obtaining water from atmospheric air that provide a temperature below the dew point can partially solve the problems of water supply. Thermoelectric modules that do not require refrigerants and are environmentally friendly have certain prospects in such systems. The purpose of the work is to study the prospects for using thermoelectric modules in systems for obtaining water from atmospheric air. The study methodology is experimental research. The results of an experimental study of the processes of condensation of moisture from atmospheric air using thermoelectric modules (Peltier elements) are presented. During experiments based on TEC1-12706 modules, the influence of supply voltage, air flow velocity and relative humidity of the environment on the condensate output was analyzed. It was established that the most energy-efficient mode is the operation mode at a voltage of 9-10 V and a current of 3.8-4.2 A, which allows avoiding module overheating. The optimal speed of radiators blowing (2.5–3.0 m/s) was determined, which ensures the best heat transfer. The results of the study showed that the specific energy consumption in the optimized mode is 0.9–1.1 kWh/l. A «critical point» of air humidity (40%) was identified, below which the condensation process becomes energetically inexpedient. The obtained data confirm the effectiveness of integrating thermoelectric water generators with photovoltaic panels to create fully autonomous water supply systems in arid regions. The scientific novelty of the conducted experimental studies is associated with the determination of the area of ​​optimal parameters of operation of thermoelectric modules, in which minimal energy costs are ensured when obtaining water from the air. The practical value lies in the possibility of creating compact devices for operation both under conditions of stable power supply and from solar panels. Recieved: 02.03.2026. Recieved: 26.05.2026. Accepted: 22.06.2026
Enhancing statcom control efficiency in power networks with photovoltaic power plants based on the integration of simatic energy suite and sentron PAC4200
This paper presents an approach to integrating the SIMATIC Energy Suite and SENTRON PAC4200 platforms into the control system of a Static Synchronous Compensator (STATCOM) in order to improve power quality in a 35 kV medium-voltage network with an interconnected photovoltaic power plant (PVPP). The relevance of the study is driven by the increasing penetration of renewable energy sources, which introduce voltage fluctuations, reactive power imbalance, and harmonic distortion into distribution networks. An integrated monitoring and control architecture is proposed, combining real-time data acquisition, analysis, and optimization functions. The SENTRON PAC4200 device is employed as the measurement layer for monitoring power quality parameters (voltage, current, power, THD, flicker, and PQ events) at key network points, while SIMATIC Energy Suite provides telemetry processing, KPI generation, implementation of automated control rules, and transmission of control commands to the STATCOM controller or PV inverters via industrial communication protocols such as IEC 61850, Modbus TCP, and OPC UA. A two-level control structure is introduced: a fast local STATCOM control loop for voltage regulation (Volt–VAR) and a supervisory SIMATIC-based loop for photovoltaic operation optimization (Volt–Watt or Watt-Priority modes). The results demonstrate that the proposed integration enhances voltage stability, reduces total harmonic distortion (THD), improves power factor, and increases system resilience during short-term grid disturbances. The system shifts from reactive compensation to proactive, data-driven power quality management, enabling loss minimization, improved PV plant availability, and reduced protection trips. The obtained results provide a foundation for implementing intelligent compensating systems in medium-voltage networks and for developing standardized integration solutions combining SIMATIC, SENTRON, and STATCOM technologies in renewable-based power infrastructure. Recieved: 18.03.2026. Recieved: 01.06.2026. Accepted: 22.06.2026
UE5 simulation methodology for autonomous uav swarms: multi-agent learning and communication resilience assessment in emergency scenarios
The article discusses an approach to building a pilot simulation environment in Unreal Engine 5 to study the behavior of a swarm of unmanned aerial vehicles in emergency response tasks. The relevance of the work stems from the fact that when searching for people, inspecting damaged areas, and avoiding obstacles, communication between devices can be unstable, and centralized control schemes can become inefficient. The study aims to develop a simplified UE5-oriented methodology that enables setting mission scenarios, simulating packet loss, latency, and short periods of communication failure, and collecting telemetry data to compare control approaches. The technique is based on a modular plugin architecture that includes Scenario Runner, Agent Framework, Communication Stress Injector, Role Manager, and Telemetry Logger. Four scenarios are proposed for the initial analysis: covering the open area, searching for targets in the urban environment, avoiding obstacles in the ruin corridor, and a mixed search-and-return mission. The result is a data structure, a set of metrics, and a simulation example of evaluating mission success, execution time, number of collisions, communication quality, and recovery from a stressful window. The proposed approach does not replace field testing, but creates a basis for early validation of ideas and preparation for further hardware validation. Recieved: 20.03.2026. Recieved: 03.06.2026. Accepted: 22.06.2026
Research of performance indicators and adjustment of operating modes of a power boiler by optimization of the fuel combustion process
The relevance of the study is determined by the necessity to ensure reliable and efficient operation of pulverized coal power boilers under conditions of using solid fuel with variable technical characteristics. Under modern conditions of shortage of design fuel and instability of the fuel base, particular importance is attached to the adaptation of boiler equipment to the combustion of low-grade coal without significant structural modifications. The purpose of the work is to investigate the operating parameters and adjust the operating modes of the TP-47 boiler by optimizing the combustion process during the combustion of off-design coal. To achieve this goal, operational and adjustment tests of a TP-47 pulverized coal drum boiler with natural circulation were carried out in the load range of 65–90 % of the nominal heat output. During the study, the influence of changes in fuel characteristics on the boiler heat output, excess air coefficient, superheated steam temperature, coal grinding quality, and stability of pulverizing systems operation was determined. It was established that the TP-47 boiler provides stable operation when firing coal with reduced calorific value without significant violation of operating parameters. A close-to-linear dependence of the excess air coefficient on the boiler heat output was determined. Deterioration of fuel grinding fineness with increasing boiler load was revealed, which may lead to increased heat losses due to mechanical incomplete combustion. The possibility of stable boiler operation at the minimum permissible load without the use of reserve fuel was established. The practical significance of the work lies in the possibility of using the obtained results for optimization of operating modes of power boilers, increasing fuel flexibility, and ensuring stable operation of thermal power equipment under conditions of variable fuel quality. Recieved: 15.03.2026. Recieved: 19.05.2026. Accepted: 22.06.2026
Development of models of electrical systems based on wireless electrical devices
The relevance of developing models of electrical systems based on wireless electrical devices is due to the fact that digital technologies are now a kind of integration platform for the interaction of various system components. The purpose of the study is to demonstrate the use of digital technologies based on wireless electrical devices that provide the development of electrical systems for electricity consumption in agricultural production. A model of the greenhouse electrical system was selected for the study. A scheme of an experimental installation was developed, the basis of which was the specialized Wi-Fi module Node MCUv3. During the study, the technical capabilities of the main brands of modern smart devices were analyzed and the intelligent control platform “Home Assistant” was selected, which was deployed on a server (mini-computer) through a special tool (virtual machine) – Virtual Box. It was found that this platform makes it possible to create automation of response to functions (entities) that represent events (including virtual ones), states or information parameters. A study of the use of Home Assistant for centralized control of wireless devices from different manufacturers was conducted. The most convenient approach was when electrical systems are controlled from a single interface, where automatic control of the greenhouse electrical system model by humidity level in the form of a virtual hygrostat was practically demonstrated. The proposed model solves a number of problems that will enable the development of electrical systems based on Home Assistant in the future. In particular: free service and integration of different manufacturers of wireless devices; a completely local solution (from one place); the ability to send push messages to a smartphone or control from a Web interface. Recieved: 29.03.2026. Recieved: 01.06.2026. Accepted: 22.06.2026
Математична модель процесу резонансного поглинання енергії електромагнітного поля при обробітку насіння сільськогосподарських культур
The article presents the results of theoretical studies on the development of a mathematical model of the process of resonant absorption of electromagnetic field energy by agricultural crop seeds. The model is based on F. Bloch’s phenomenological theory of magnetic resonance, according to which a system of microparticles is described through its macroscopic characteristics — the magnetisation vector as the sum of magnetic moments per unit volume of the substance. A test seed sample of 100 g, with electrophysical parameters that are uniform across the volume and constant over time, is treated as a physical point with an averaged value of magnetic susceptibility, which corresponds to real conditions of seed treatment without unpacking the bag containers. Based on the quantitative content and magnetic properties of the elements and molecules of a plant cell, the macroscopic characteristic of the system is determined — the magnetisation vector M = 13.125 mA/m at the longitudinal constant magnetic field intensity H = 625 A/m. The interaction of the magnetisation vector with the longitudinal constant and transverse alternating magnetic fields is analysed, and the conditions for the occurrence of magnetic resonance are substantiated, under which the oscillation frequency of the alternating magnetic field coincides with the precession frequency of the magnetisation vector. On this basis, a system of Bloch equations is formed to describe the process of resonant absorption of electromagnetic field energy in the seed material. The proposed model provides a theoretical foundation for establishing rational modes of pre-sowing electromagnetic seed treatment that ensure maximum energy absorption at minimum energy expenditure and contribute to improving seed sowing qualities and the productivity of agricultural crops. Recieved: 14.04.2026. Recieved: 16.06.2026. Accepted: 22.06.2026
Method of remote monitoring of biomethane production parameters
The relevance of the study is determined by the need to improve the reliability, stability and controllability of biomethane production from agricultural organic waste. A key problem in the automation of biomethane plants is the insufficient reliability and continuity of remote monitoring data, which limits predictive control, anomaly detection and the development of digital twins. The purpose of the study is to develop a theoretical and methodological approach to ensuring data reliability and continuity in remote monitoring systems based on an integrated sensor-edge-SCADA architecture. The study applies system analysis, structural modelling and an analytical review of modern IoT, SCADA, edge computing and digital twin approaches. A method is proposed that includes multiparametric data acquisition, edge-based validation, calculation of an integral data reliability index and transmission of validated data to SCADA or cloud analytics. The proposed approach forms a methodological basis for further experimental validation and implementation of predictive analytics in agricultural biomethane plants. Recieved: 28.03.2026. Recieved: 21.05.2026. Accepted: 22.06.2026
Efficiency of the application of distributed generation facilities based on biogas in Ukraine
With the beginning of hostilities in Ukraine and damage to energy infrastructure facilities, the construction of new distributed generation facilities using local alternative fuels has become even more relevant, which can ensure the stability of the power system and compensate for lost generating capacity. The prospect of introducing new distributed generation plants (gas piston, gas turbine) creates a need for additional volumes of natural gas, which increases the importance of its replacement in the energy sector through the use of biogas/biomethane. The object of the study is the processes of electricity production from biogas at cogeneration plants in Ukraine. The purpose of the work is to substantiate the directions of expanding the use of biogas for the development of distributed energy and to identify promising ways of implementing these technologies in Ukraine. The current and potential possibilities of electricity production at biogas plants for different regions of Ukraine are analyzed. An analysis of the technical limitations of the application of distributed generation based on biogas is presented and technical measures are proposed to increase the efficiency of electricity generation at biogas plants. The possibility of using cogeneration units of biogas complexes in peak or semi-peak modes for balancing the electricity network is considered. From a technical point of view, for this, existing biogas plants need to be modernized, including the installation of additional gas holders and an increase in electricity generation capacity. Practical recommendations are proposed for the application of distributed generation based on biogas during the period of war and post-war recovery in Ukraine. Recieved: 13.03.2026. Recieved: 09.05.2026. Accepted: 22.06.2026
Analysis of sustainability and promising directions for using bioenergy potential of Ukraine
Bioenergy is today an integral part of the European energy sector, including Ukraine as a member of the Energy Community. In conditions of instability in global energy markets, bioenergy can ensure the diversification of energy carriers and significantly increase the reliability of energy supply. One of the main prerequisites for the successful development of the bioenergy sector is the availability and effective use of biomass potential. At the same time, preference is given to sustainable types of biomass feedstocks, which ensure the production of biofuels with a low carbon footprint and do not compete with food production. The purpose of the study is to analyse the sustainability of Ukraine's biomass energy potential and identify the most promising areas of its use. The analysis of the sustainability of biomass potential was carried out based on data of 2021, the last year without the impact of military actions on its volume and structure. The level of sustainability of individual components of the potential was assessed as high, medium or low. The comprehensive assessment takes into account the provisions and sustainability criteria of the EU Renewable Energy Directive, as well as local conditions in Ukraine, which do not always coincide with European ones. Most of the components of Ukraine's bioenergy potential have a high degree of sustainability. To increase the level of sustainability of liquid biofuels, it is recommended to reorient to lignocellulosic feedstock or to biomass that, in Ukrainian conditions, provides advanced biofuels from an informal point of view. Recieved: 02.03.2026. Recieved: 26.05.2026. Accepted: 22.06.2026
Intellectualization of vacuum circuit breakers in medium- and high-voltage networks
The relevance of the study is обусловлена the need to improve the reliability and safety of switching equipment in medium- and high-voltage networks under conditions of substation digitalization and the transition to condition-based maintenance. The aim of the study is to substantiate the feasibility of using vacuum circuit breakers in combination with digital monitoring systems and to develop an approach to the integrated assessment of their technical condition. To achieve this aim, analytical, comparative, and structural-functional research methods were applied; scientific sources and the provisions of IEC 62271-100 and IEC 61850-3 standards were analyzed. The paper summarizes the advantages of vacuum circuit breakers in comparison with oil, air, and SF6 analogues and identifies the most informative diagnostic parameters, namely operating time, contact resistance, local overheating, drive vibration condition, and consumed switching life. An integrated technical condition index is proposed, combining electrical, thermal, mechanical, temporal, and resource-related indicators and enabling the determination of equipment maintenance priorities. It has been established that the integration of vacuum circuit breakers with digital controllers, sensors, and the SCADA level based on IEC 61850 increases the informativeness of monitoring, facilitates early detection of degradation processes, and creates prerequisites for predictive maintenance. The practical significance of the results lies in the possibility of their application in the modernization of switchgear at industrial and agro-industrial enterprises. Recieved: 23.02.2026. Recieved: 15.05.2026. Accepted: 22.06.2026
Numerical simulation of aerodynamic processes during the flow around a wind turbine with wind flow concentrator
A mathematical model has been developed and a numerical calculation of aerodynamics during the flow around vertical axis wind turbines (VAWTs) using a wind flow concentrator has been performed. Two modifications of the concentrator placement at different angles of the external wind flow are considered. When developing a mathematical model of turbulent flows, the Navier-Stokes equations were used and a modified k-ε turbulence model was selected. As a result of numerical calculations in 2D formulation of the unsteady aerodynamic problem, the distributions of speeds and pressures in the wind turbine-wind flow concentrator system were obtained. It was found that the quasi-stationary rotor rotation mode occurs approximately 1 s from the start of turbine operation. It is shown that the presence of a wind flow concentrator increases the local values ​​of air speeds when flowing onto the wind turbine blades. The dependence of the rotor speed on time for two configurations of the concentrator placement relative to the direction of the external wind flow was obtained. As a result, it was shown that the use of a wind flow concentrator makes it possible to increase the efficiency and productivity of a wind turbine with vertical axis of rotation. Recieved: 23.02.2026. Recieved: 25.05.2026. Accepted: 22.06.2026
Influence of voltage deviation on the drive characteristics of working machines with dc motors of independent and parallel excitation at the torque of static supports linearly dependent on the angular velocity
Studies on the influence of deviations in power quality indicators on the technological and energy characteristics of working machines and mechanisms in asynchronous electric drives have shown that when they deviate, productivity decreases and specific energy consumption increases. However, there are no studies on the influence of voltage deviation on DC electric drives. The purpose of the study is to establish the influence of voltage deviation in electric drives with DC motors of independent and parallel excitation on the technological and energy characteristics of working machines with a fan mechanical characteristic When the voltage deviates, the angular velocity of DC motors of independent and parallel excitation changes, which causes a change in the productivity of the working machine. In DC motors of independent and parallel excitation with a saturated magnetic system, the dependence of the productivity of the working machine on the voltage change is linear When the voltage deviates, constant and variable power losses in a DC electric motor change. It is proposed to conduct an energy assessment of a DC electric drive by specific electricity consumption. A study of the influence of voltage deviation on the energy characteristics of working machines with fan mechanical characteristics, which are driven by DC motors of independent and parallel excitation, was conducted. It was established that with a decrease in voltage, the specific electricity consumption increases. Recieved: 23.03.2026. Recieved: 15.05.2026. Accepted: 22.06.2026
Training of specialists for home renovation in a "one-stop shop" package
The training program for stakeholders and the “Training of Trainers” program were developed within the framework of the LIFE23-CET-BUSHROSSs project GA 101167619 based on the identified skills deficit and the developed set of necessary professional qualifications for specialists who will be involved in comprehensive customer service training in the context of home renovation. The programs were prepared by CISB with the participation of all partners who made their valuable contribution to the development of the training programs. This article) presents the Curricula and Training Program for both the Train-the-Trainer (ToT) course and the professional training courses for national One-Stop-Shop (OSS) experts. It builds upon the professional qualification profiles, which identified the core knowledge, skills, and competences required for four professional categories: Economists, Technical Experts, Legal Advisers, and Social Workers. It translates those qualifications into concrete, modular curricula and pedagogical structures. The Program ensures the consistent, high-quality preparation of trainers and learners across partner countries (Bulgaria, Greece, Ireland, Poland, Slovenia and Ukraine) through a modular, flexible, and digital training approach. Recieved: 27.04.2025. Recieved: 16.06.2026. Accepted: 22.06.2026
The relevance of the study is обусловлена the need to improve the reliability and safety of switching equipment in medium- and high-voltage networks under conditions of substation digitalization and the transition to condition-based maintenance. The aim of the study is to substantiate the feasibility of using vacuum circuit breakers in combination with digital monitoring systems and to develop an approach to the integrated assessment of their technical condition. To achieve this aim, analytical, comparative, and structural-functional research methods were applied; scientific sources and the provisions of IEC 62271-100 and IEC 61850-3 standards were analyzed. The paper summarizes the advantages of vacuum circuit breakers in comparison with oil, air, and SF6 analogues and identifies the most informative diagnostic parameters, namely operating time, contact resistance, local overheating, drive vibration condition, and consumed switching life. An integrated technical condition index is proposed, combining electrical, thermal, mechanical, temporal, and resource-related indicators and enabling the determination of equipment maintenance priorities. It has been established that the integration of vacuum circuit breakers with digital controllers, sensors, and the SCADA level based on IEC 61850 increases the informativeness of monitoring, facilitates early detection of degradation processes, and creates prerequisites for predictive maintenance. The practical significance of the results lies in the possibility of their application in the modernization of switchgear at industrial and agro-industrial enterprises. Recieved: 18.01.2026. Recieved: 01.04.2026. Accepted: 17.04.2026.
Analysis of solar drying methods and design schemes of solar dryers
Global warming caused by greenhouse gas emissions into the atmosphere requires decisive action toward decarbonization, primarily in the energy sector, that is, a transition to carbon-free, particularly renewable, energy sources. Thermal drying of agricultural products is one of the sectors that requires significant energy consumption, which leads to CO2 emissions. The use of solar radiation energy for drying processes can significantly reduce the carbon footprint as well as the consumption of energy from fossil resources. However, one of the main obstacles to the widespread implementation of solar dryers is the variability of solar radiation during the technological process. It is determined by the time of day, season, local climate, and meteorological conditions. This leads to the risks of instability of temperature and humidity regimes and deterioration of product quality. The aim of the article is to analyze drying methods and structural schemes of solar dryers used in modern technological processes. The study used the methods of analysis, comparison, and generalization of the results of scientific research on solar drying processes. As a result, it was determined that the efficiency of solar drying significantly depends on the method of heat supply, the organization of air convection, the ability to compensate for periods of low insolation by means of additional energy sources or storage, as well as on the structural type of the dryer. In accordance with the stated objective, it is necessary to select a method that will ensure an efficient drying process while complying with the requirements for preserving product quality. Recieved: 18.01.2026. Recieved: 01.04.2026. Accepted: 17.04.2026.
Research of rotary transformer monitoring and regulation system of biogas reactor operation
This article is devoted to improving the method of transmitting electrical energy to rotating components of electromechanical systems, particularly in explosive or chemically aggressive environments. The objective of the study is to justify the use of a transformer with a rotating secondary winding for contactless power transmission to the rotating part of a submersible multifunctional electromechanical transducer (PMET) as part of a system for monitoring and regulating the operating mode of a biogas reactor. In the developed system, the transformer structure is implemented as a rotating transformer (RT) with axially arranged windings: the primary winding is rigidly fixed on a stationary steel core, and the secondary winding is mounted on the PEMP. To evaluate the dynamic properties of the RT, a series of measurements was conducted while varying the frequency of the input P-shaped signal from 1.5 to 7 kHz. The RT power supply circuit is based on an IR2153 PWM driver that controls two MOSFET transistors. Analysis of the electromagnetic field and the distribution patterns of magnetic induction was performed in the Comsol Multiphysics software environment. The choice of a 2 kHz supply frequency was confirmed by the achieved power and efficiency values. The proposed OT is distinguished by its topological features and operating mode in measurement cycles. To eliminate the influence of the sensor power supply system on the thermal profile, a special algorithm for the OT’s operation was developed. The resulting prototype demonstrates an average efficiency of 75% in the output power range of 300–500 mW. The proposed topology makes it possible to increase the power of the operational technology system without compromising its size, cost, or performance. Future research directions include ensuring the electromagnetic compatibility of the monitoring and control system and investigating its impact on the substrate of the biogas reactor. Recieved: 20.01.2026. Recieved: 23.03.2026. Accepted: 17.04.2026.
Power supply for domestic gas boilers from inverters with modified sinusoid
The article discusses the features of powering domestic gas boilers from autonomous power sources based on inverters with a modified sine wave. The electrical characteristics of such inverters and their impact on the operation of the main components of modern boilers are analyzed: circulation pumps, fans, electronic control boards, and ignition systems. The risks of using non-sinusoidal voltage are identified, in particular, increased heating of electric motors, incorrect operation of sensors and automation units, and increased electromagnetic interference. The purpose of the study is to assess the impact of the output voltage waveform of an inverter with a modified sine wave on the start-up and stable operation modes of domestic gas boilers, as well as to determine the effectiveness of using a filter to reduce higher harmonic components and to justify the admissibility of using such a backup power source. An analysis of the output voltage of an inverter with a modified sine wave was performed using an inductive filter of higher harmonics from the standpoint of reducing higher harmonic components in the voltage curve, by simulating this process using the EWB 32 electronic workbench application. The feasibility of using inverters with a modified sine wave to ensure stable and safe operation of gas boilers in conditions of power supply interruptions was substantiated. Practical recommendations for the selection and operation of backup power supply systems in domestic conditions were proposed. The proposed method of using an inverter with a modified sine wave and an additional induction filter has advantages over existing methods. It allows the use of inexpensive inverters to power domestic gas boilers, ensuring energy efficiency and reliability of their operation. Recieved: 15.01.2026. Recieved: 19.03.2026. Accepted: 17.04.2026.
Development and research of an electrical control system for the electric drive of a cascade pumping unit
The paper presents the results of a study of an automated control system for a cascade pumping unit with variable-frequency electric drive control aimed at improving the energy efficiency of water supply systems. The proposed system is focused on increasing energy efficiency and optimizing hydraulic processes in water supply networks with variable flow rates. An automatic control algorithm has been developed that ensures pipeline pressure stabilization by continuous adjustment of the electric motor rotational speed in accordance with the current pressure value obtained from a pressure sensor. Special attention is paid to the cascade pump control principle, which enables effective coordination of pump operation with actual water consumption. Under low-load conditions, the required network pressure is provided by the operation of a single pump with adjustable speed, while the additional pump is automatically disconnected. This approach eliminates idle and low-efficiency operating modes, significantly reduces energy consumption, and decreases equipment wear by reducing the number of starts and prolonged operation at partial load. An experimental study of the energy and operating characteristics of a cascade pumping unit consisting of two induction motor drives with different rated parameters has been carried out. Control was implemented using variable-frequency regulation, which provides smooth adjustment of system flow rate and pressure depending on hydraulic load conditions. During the experiments, relationships between changes in consumed current, pressure, and rotational speed were obtained for various operating modes involving one or two pumps within the cascade system. Based on simulation modeling and experimental verification, quantitative relationships describing the influence of variable-frequency control on flow formation and pressure stability in the network were established. It is shown that the use of a frequency converter ensures system adaptability to dynamic load variations, reduces electrical energy losses, decreases starting stresses on electric drives, and generally enhances the reliability of pumping infrastructure operation. <span style="font-size: 11.0pt; mso-bidi-font-size: 14.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; color: black; mso-themecolor: text1; mso-ansi-language: UK; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">The obtained results have practical significance for the design of new and the modernization of existing water supply and irrigation systems, enabling improved energy performance, extended equipment service life, and higher quality of technological parameter control<span style="font-size: 11.0pt; mso-bidi-font-size: 14.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; color: black; mso-themecolor: text1; mso-ansi-language: UK; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">. <span style="font-size: 11.0pt; mso-bidi-font-size: 14.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; color: black; mso-themecolor: text1; mso-ansi-language: UK; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Recieved: 29.12.2025. Recieved: 01.03.2026. Accepted: 17.04.2026.
Potential loss as a criterion for the selection of electrical equipment diagnostic and protection systems
Solutions aimed at ensuring safety and minimizing losses, implemented in both operating and newly developed protection systems for power equipment, require the improvement of existing loss calculation methodologies, the justification of new performance indicators, cost analysis, and the assessment of the consequences of poor power quality. When selecting diagnostic and protection means for power equipment, the situation is not entirely unambiguous or definite. A wide range of alternative protection systems and devices may be considered, each of which can be regarded as technically justified. The substantiation of new decision-making criteria for the selection of protection systems, diagnostics, and the forecasting of accident development is one of the key directions in identifying pre-emergency states and in the development of relay protection systems for electrical equipment. This paper considers the issues of selecting the structural components of relay protection systems based on a justified criterion of potential damage. A multilevel system for diagnostics and protection of electrical equipment is proposed. The developed system enables the design of relay protection schemes and the identification of damage types depending on the probable emergency condition of electrical equipment and the expected level of losses. Recieved: 14.01.2026. Recieved: 16.03.2026. Accepted: 17.04.2026.
Improvement of the efficiency of vertical-axis wind turbines using a wind flow concentrator
The relevance of the study is driven by the necessity to enhance energy efficiency and improve the start-up characteristics of autonomous power generation systems, particularly vertical-axis wind turbines, in low-potential wind flow conditions (3–5 m/s) typical for most regions of Ukraine. The purpose and objectives of the research consist in the development and investigation of a stationary aerodynamic wind flow concentrator of the confuser type to lower the self-starting threshold and increase the output power of the wind generator. The research methods are based on experimental modeling of a modified electromechanical system (Savonius rotor with a PMG-20 generator) in a subsonic wind tunnel under an active electrical load of 230 Ω. The research results demonstrated that the application of guide vanes enables the implementation of the Venturi effect, providing local air acceleration on the working blades and shielding of the blades moving against the wind. A 30% reduction in the self-starting speed threshold (from 2.7 m/s to 1.9 m/s) was experimentally confirmed. It was established that at a wind speed of 4.0 m/s, the output electrical power increases by 3.6 times compared to the baseline rotor configuration. Conclusions: the application of the developed aerodynamic concentrator design is an effective scientific and technical solution for expanding the operating range and improving the generation stability of low-power vertical-axis wind turbines. Recieved: 28.01.2026. Recieved: 21.03.2026. Accepted: 17.04.2026.
Research of microflame low-emission natural gas combustion technology adapted for chinese-type power boilers
The relevance of the study is обусловлена the need to reduce nitrogen oxide emissions during natural gas combustion in thermal power installations and to improve the energy and environmental efficiency of gas-fired equipment. The implementation of low-emission combustion technologies capable of ensuring stable fuel combustion with minimal pollutant formation is of particular importance. The aim of the study is to investigate the processes of microflame low-emission natural gas combustion and to evaluate the efficiency of a high-velocity jet burner in reducing NOx formation, equalizing the temperature field, and improving the environmental characteristics of the combustion process. To achieve this goal, numerical CFD simulation of combustion processes was carried out in the ANSYS Fluent software environment using the RANS approach and the standard k–ε turbulence model. The influence of burner geometric parameters and excess air ratio on the temperature regime and NOx formation processes was investigated. Experimental studies of a 200 kW microflame burner were performed using a GASMET DX4000 gas analyzer. It was established that the proposed burner design ensures the formation of multiple microflames, intensifies fuel-air mixing, and provides a more uniform temperature distribution in the combustion chamber. It was determined that the most efficient operating mode is achieved with an air channel diameter of 16 mm and an excess air ratio of α ≈ 1.4. The obtained results showed that the NOx concentration in combustion products does not exceed 50 mg/m³, which complies with current requirements for low-emission combustion technologies. The practical significance of the study lies in the possibility of using the proposed microflame burners for modernization of existing thermal engineering installations and improvement of the environmental safety of natural gas combustion processes. Recieved: 03.01.2026. Recieved: 09.03.2026. Accepted: 17.04.2026.
Research of energy consumption of livestock complexes using methods of systematic bioenergy analysis
Solving the food problem in Ukraine is impossible without further increasing the production of livestock products, and, consequently, the construction of new, reconstruction and improvement of the efficiency of operation of existing livestock complexes with industrial technology and a high level of electrification and automation of production processes. Considering agriculture as a system where the conversion and accumulation of solar and other types of energy into food takes place using plants and animals, the problem of energy efficiency of agricultural production must be solved on the basis of a comprehensive analysis of energy consumption not only within each sphere, but also the entire energy flow of the agricultural complex. The constant growth of energy resource consumption with a simultaneous decrease in their supply, unjustifiably large and irrational consumption of electricity, fuel and feed, characteristic of many branches of agriculture and, above all, animal husbandry, a significant increase in the cost of energy resources and other reasons have determined the importance and relevance of energy-saving policy. Increasing the level of rational use of energy resources in agricultural production is of great importance and is characterized by significant savings in material and energy resources. Thus, saving only 1% of energy resources in Ukrainian agriculture is equivalent to saving 8700 GJ per year. Therefore, the task of optimal management of energy consumption in agriculture should be considered as an alternative to the development of generating capacities. System bioenergy analysis significantly exceeds the capabilities of technical and economic analysis to identify reserves of saving fossil energy resources. If in the process of conducting a technical and economic analysis, shortcomings and their causes are identified, then the result of a system analysis is the search for specific ways to eliminate these shortcomings and increase the efficiency of the functioning of the object under study. Recieved: 02.02.2026. Recieved: 26.03.2026. Accepted: 17.04.2026.
Using the automationml ar apc recommendation for integration of engineering tools in the control system lifecycle
Automation of software creation is possible when frameworks are available, one of which is PACFramework. However, automation tools require consistency with computer-aided engineering systems, which implies automated data import and export. Therefore, neutral data representation models are increasingly used to ensure interoperability between engineering tools. One of the standards designed for engineering data exchange in industrial automation is AutomationML. In particular, the AutomationML Application Recommendation Automation Project Configuration (AR APC) defines a model for representing the hardware configuration of automation systems. This paper investigates the applicability of the AR APC recommendation as a format for representing hardware configuration and master data in the lifecycle of industrial control systems. The study is carried out in the context of the PFw2 lifecycle architecture, where master data are considered a central element for the integration of engineering tools. The structure of the AR APC model is analyzed with respect to its capability to represent devices, modules, channels, and process variables. Based on this analysis, the correspondence between AR APC elements and the lower levels of the PFw2 control model is examined. The results show that the AR APC model fully covers the Channels sublevel and partially covers the Process Variables sublevel in the hierarchy of the control model. Therefore, the model can be used as a basis for representing lower-level master data and for integrating engineering tools used in the lifecycle of industrial control systems. The results demonstrate the potential of using AutomationML AR APC to ensure consistent engineering data exchange between different engineering environments. Recieved: 27.12.2025. Recieved: 19.02.2026. Accepted: 17.04.2026.
On the priority use of reactive power compensation devices
The analysis of the results of research by scientists on reactive power compensation in the distribution networks of the distribution system operator (DSO) and in the networks of powerful electricity consumers using synchronous motors, which are a common element of electric drives in the technological processes of a number of enterprises, is presented. The author's comments on the formulation and solution of the tasks of reactive power compensation (RPC) in electrical networks using synchronous motors (SMs) are given. Therefore, it is relevant to determine the limits of the technical and economic characteristics of SMs for their use together with low-voltage capacitor units (LVCU) for RCS in electrical networks of industrial enterprises. The influence of the operating mode of the enterprise and the parameters of the SMs on the economic feasibility of their use for reactive power compensation is studied. The values ​​of the relative economic reactive load of the SMs and the influence of the speed characteristics of the SMs, operating modes of enterprises and the parameters of the electrical network with connected SMs and VCs on its value are obtained. Recieved: 23.01.2026. Recieved: 25.03.2026. Accepted: 17.04.2026.
Life cycle assessment (LCA) and embodied carbon in energy and heat supply systems
Life Cycle Assessment (LCA) is one of the key tools for evaluating the environmental performance of energy and heating systems in the context of global decarbonization. In the context of the transition to highly efficient and renewable energy sources, it is becoming increasingly important to assess not only operational emissions, but also embodied carbon associated with the production, transportation, installation, maintenance, and disposal of materials and equipment. The purpose of the article is to summarize current scientific and methodological approaches to the application of LCA for heat supply, energy supply, and building engineering systems, as well as to analyze the role of embodied carbon in shaping the total environmental impact throughout the life cycle. Special attention is paid to methodological features of determining system boundaries, functional units, and interpreting LCA results. The research methods are based on a systematic analysis of international standards, scientific publications, and industry reports on LCA, whole-life carbon, and the assessment of environmental performance of energy systems. Approaches to assessing centralized heat supply, heating, ventilation, and air conditioning systems, as well as technologies using renewable energy sources, are analyzed. Along with global warming potential, indicators such as primary energy consumption, natural resource use, water footprint, waste generation, acidification potential, and eutrophication potential are considered. The results of the generalization show that with a decrease in operational emissions, the share of embodied carbon in the total environmental impact increases and can constitute a significant part of the total life cycle of energy systems. The conclusions can be used as a methodological basis for improving approaches to the design, modernization, and strategic planning of energy infrastructure decarbonization. Recieved: 03.01.2026. Recieved: 15.03.2026. Accepted: 17.04.2026.
Temperature modes of the active combustion zone of microjet burners with multi-row fuel supply
The research objective is to study temperature conditions in stabilizer-type burners with a three-row fuel supply system, designed for operation at excess air ratios of 1.1 to 1.5. The study was conducted using CFD modeling with the RANS (Reynolds Averaged Navier-Stokes) approach. The main principles of heat transfer in the microjet burners under consideration were analyzed. Particular attention was paid to the impact of the design and operating parameters of the burner system on various thermal characteristics. Results of CFD modeling of temperature fields in the active combustion zone were obtained when fuel gas was supplied to different rows of gas supply holes. The presented data from the computational studies indicate that the temperature fields differ significantly depending on the row number of the fuel gas supply hole. The results of computational experiments on the fields of root-mean-square temperature pulsations when fuel was supplied to different rows of gas supply holes are presented. Particular attention is paid to analyzing the thermal state of the recirculation zone behind the flame stabilizer. According to the data obtained, extreme temperatures in the recirculation zone occur for the three fuel supply situations considered. Patterns in the temperature non-uniformity coefficient variation along the channel length are examined. It is shown that the highest values ​​of this coefficient are observed when fuel is supplied to the third section, and the lowest values are observed in the first section. A relatively sharp decrease in the temperature non-uniformity coefficient occurs in the zone located near the end of the stabilizer. The data from these studies can be used in energy engineering practice for the design and modernization of burner devices operating with variable excess air coefficient values and variable thermal performance of heat and power equipment. Recieved: 17.01.2026. Recieved: 05.03.2026. Accepted: 17.04.2026.
The use of biomass as a factor for increasing the energy-ecological efficiency of boiler plants and ensuring energy sustainability in conditions of martial law
The disruption of energy infrastructure functioning in Ukraine under martial law exacerbates the problem of ensuring reliable heat supply. The dependence of boiler plants on natural gas reduces their resilience to crisis impacts, highlighting the need to transition to alternative and locally available energy sources, particularly biomass. The aim of this article is to assess the potential of using biomass to enhance the energy and environmental efficiency of boiler plants and ensure their energy resilience. To achieve this goal, the study focuses on identifying key characteristics of biofuels, evaluating their impact on boiler performance, and substantiating the feasibility of implementing bioenergy solutions based on international experience. The study employs a comparative analysis of the characteristics of natural gas and various types of biomasses, a systems approach to considering boiler plants as integrated energy-technological systems, calculation methods for assessing thermal and economic performance indicators, as well as elements of experimental analysis of fuel composition and generalization of foreign experience. It has been established that using biomass contributes to increasing the energy autonomy of boiler plants and reducing the cost of heat production compared to natural gas. The efficiency of biofuel boiler operations depends on the consistency of their technological components and the consideration of fuel properties. The feasibility of using wood pellets and torrefied biomass for medium-capacity boiler plants is substantiated, while agro-biomass requires accounting for corrosion and slagging risks. The adaptation of European bioenergy models to domestic conditions is demonstrated. The use of biomass is an effective approach to improving the energy-environmental efficiency and resilience of heat supply systems under martial law. Transitioning to biofuels ensures diversification of energy sources, reduces dependence on imported resources, and promotes the development of local fuel markets. Implementing this approach requires a comprehensive consideration of technical, economic, and resource factors. Recieved 2025-11-21 Recieved 2026-01-21 Accepted 2026-02-11
Mathematical modeling of dynamic characteristics of rotary-blades wind power installations under stochastic wind loading conditions
The integration of rotary-blades wind power installations into modern energy systems is becoming increasingly important due to the rapid growth of the share of renewable energy sources. At the same time, the operation of wind power installations is significantly different from traditional sources of generation, as their performance directly depends on the speed and direction of the wind, which are random in nature. This leads to significant fluctuations in the mechanical and electrical parameters of the system, complicates the process of regulating the frequency and active power of the generator, and creates increased requirements for the stability of the power system as a whole. The purpose of the study is to develop a mathematical model of a rotary-blade wind power installation taking into account stochastic wind load for analyzing the dynamics of the installation and tuning the wind generator frequency control algorithms. Mathematical modeling is based on equations of rotational motion of the rotor and wind wheel, described through torque and moment of resistance forces, as well as on equations of air flow motion, taking into account turbulence and random changes in speed and direction. For the digital implementation of control algorithms, discretization of equations and recurrence relations for the rotor angular velocity and blade orientation angle are used. A simplified representation of torque and resistance in the form of polynomial dependencies provides sufficient accuracy with minimal computational costs and allows for effective testing of control algorithms in real time. The proposed model adequately reproduces the dynamic characteristics of the installation, takes into account stochastic wind factors, and allows for the implementation of digital control systems with high blade orientation accuracy. The use of the model ensures increased stability and efficiency of rotary-blade wind power installations in real operating conditions, guarantees reliable electricity production under variable weather conditions, and preserves the key dynamic properties of the system with minimal resource consumption. Recieved 2025-12-07 Recieved 2026-02-02 Accepted 2026-02-11
Multi-agent deep reinforcement learning in the path planning problem
This work is devoted to multi-agent deep reinforcement learning in the path planning problem. The use of UAV swarms in precision agriculture is justified. It is shown that for the use of drone swarms it is necessary to apply artificial intelligence, in particular reinforcement learning. The task of path planning in the presence of poor quality or absence of GPS navigation is set. The use of the Multi-Agent Proximal Policy Optimization method is proposed. The results obtained showed high quality of path planning in the presence of obstacles and poor quality or absence of GPS navigation. Recieved 2025-12-27 Recieved 2026-02-02 Accepted 2026-02-11