Bulletin of Lviv National Environmental University. Series Agroengineering Research

Using online learning services that incorporate artificial intelligence

V. Fiialkovskyi , kh. Mozul , S. Shtrohryn , P. Lub , L. Chukhrai — Fri, 20 Dec 2024 00:00:00 +0200

The text summarizes the experiences, advantages, and disadvantages of using AI technologies in education. It analyzes the current state of artificial intelligence in this field and evaluates various modern AI equivalents, justifying their potential use. The overview includes popular online learning services that incorporate AI technologies, utilized by both educational institutions and manufacturing companies. The focus is primarily on language models and services such as ChatGPT, Microsoft Gemini, and Na Urok. It highlights how AI can provide information and answers across various subjects, thereby helping to expand knowledge. The authors also outline a list of tasks in higher education where AI technologies can be effectively applied, making learning more engaging for students and easing the workload for teachers. The text discusses the advantages and disadvantages of specific online learning services that employ AI technologies, summarizing their accuracy, reliability, and ease of use. Despite certain shortcomings of existing AI, it emphasizes its significant advantages over traditional information searches, including real-time data collection, enhanced accuracy, and reduced inconsistency. The incorporation of these AI tools in the educational process can improve query correctness, data collection accuracy, and, consequently, the quality of information obtained for educational content. It concludes that AI holds considerable potential for advancing the educational process and its efficiency. Additionally, the authors note the growing global interest in AI technologies within the manufacturing sector, linking this trend to the future knowledge requirements for students. Ultimately, it is established that the use of AI can significantly enhance the effectiveness of both the educational process and other areas.

Impact of modern information technologies on the processes of initiating and planning the community and regional development projects

Fri, 20 Dec 2024 00:00:00 +0200

An analysis was conducted on the development status of communities and regions, leading to the identification of a need for projects that utilize various information technologies. Additionally, it was recognized that a method is required to assess the informational capacity of project offices responsible for implementing community and regional development initiatives. The analysis highlighted the unique aspects of employing modern information technologies in project management within these project offices. It is suggested that the assessment of information development levels in project offices should be based on an exploration of the interconnected processes of digitalization, digitization, and digital transformation. Accordingly, project offices can be classified into three distinct development levels. The findings indicate that leveraging modern information technologies significantly influences the initiation and planning phases of community and regional development projects. These effects are evident in management tasks involving the

collection and analysis of large volumes of data.

An approach to evaluating the level of information development of project offices engaged in community and regional development projects has been presented. This approach focuses on key indicators such as the speed of information access, the quality of decision-making by project managers, and the overall information development status of the project offices.

Implementing this approach allows for the consideration of the unique aspects related to generating data on project environment indicators. These indicators form the foundation for selecting appropriate information technologies that will facilitate the effective execution of community development projects across various sectors, ensuring optimal resource use and the achievement of strategic community and regional development goals.

Based on this approach, a quantitative evaluation of the information development indicators and levels of project offices under specified conditions was conducted. The results revealed that the fastest information access speeds occur in environmental projects, at approximately 80 KB/sec, while social projects exhibited the slowest access speeds at 32 KB/sec. Moreover, the highest improvement in decision-making quality, at around 25%, was seen in transport projects with the aid of information technology, compared to a 20% improvement in social projects. It was also discovered that different types of projects employ varying levels of information technology, impacting both the speed of information access and the quality of management decision-making by project managers.

Methods of using UTM tags for site traffic monitoring and web analytics

kh. Mozul , P. Lub , L. Chukhrai , S. Shtohryn , V. Fiialkovskyi — Fri, 20 Dec 2024 00:00:00 +0200

The article examines the significance of web services and the Internet in promoting products through social networks and websites. It highlights that companies utilizing web applications and social networks aim to connect with their audience and attract more customers. The research identifies the advantages of marketing on social networks, which are currently recognized as some of the most effective methods for promoting goods and services. Additionally, the article discusses the development of IT tools that enable the monitoring of user activity on social networks, a relevant issue for modern enterprises. The authors evaluate the technical capabilities of tracking users in the global network through web analytics tools. These tools provide developers and site owners with insights into user behavior, navigation patterns, and interests. The article outlines both the advantages and disadvantages of web analytics tools and describes the primary metrics - digital indicators that include views, purchases, visits, and targeted actions. It details the application of Urchin Tracking Module (UTM) technology and the Google Analytics system. The methods for utilizing UTM tags and generating reports on user activity on websites are defined. It explains how to create a UTM tag, including the parameters and tracking variables involved. The role of each component in identifying the source of website traffic is discussed, allowing for effective tracking of new user flows. Finally, the article lists the results that can be achieved through proper implementation of UTM tags and the Google Analytics system, presenting the outcomes of specific Google Analytics reports and an evaluation of the increased activity of website users.

Intelligent information systems for managing the traceability of agricultural products

A. Zheliezniak , V. Ptashnyk , R. Padiuka , V. Smolinskyi , V. Stanko — Fri, 20 Dec 2024 00:00:00 +0200

The development of agriculture in modern conditions must take into account not only technological production factors and the efficient use of resources but also the quality requirements for agricultural products. Ukraine is establishing legislative measures for managing agrarian supply chains. Consequently, food producers need to automate the process of tracking the traceability of agricultural products. This automation will enable processing companies to implement internal quality standards that comply with both EU regulations and Ukrainian legislation. Food producers can be legally held accountable for food safety at all stages, from production to retail sales. This makes traceability a critical issue for these enterprises, particularly as users of information systems and technologies. By introducing specialized intelligent information technologies, manufacturers and processing companies can manage their supply chains more effectively and enhance their competitiveness in both domestic and international markets.

The article analyzes the potential for employing intelligent information systems to manage supply chains and the traceability of agricultural products. It discusses the main components of an intelligent information system that could help ensure product traceability from production to sale. It also describes the processes that affect traceability and can be automated, including identification and labeling, inventory management systems, and the implementation of technologies and tools for tracking. Furthermore, the authors explore additional technologies that can support agricultural products, examining the use of contactless data exchange technologies and tracking tools, such as RFID. Finally, they propose solutions for addressing the challenges of product traceability for agricultural producers through intelligent information technologies.

Utilization of intelligent information technologies for resources management in agricultural enterprises

P. Lub , O. Kovalyshyn , L. Chukhrai , V. Stanko, N. Zaplatynskyi — Fri, 20 Dec 2024 00:00:00 +0200

The demand for innovative agricultural technologies and an understanding of the conditions of market globalization are increasingly critical. This article analyzes the role of artificial intelligence (AI) in optimizing resource management within agricultural enterprises through big data analysis. It demonstrates the essential need for agribusinesses to develop and enhance rapid and efficient scenario modeling for decision-making, integrating these models to assess future benefits, expected profits, and forecast payback periods. The importance of implementing information technologies aimed at innovative processes in the agricultural sector, both at a general level and within specific subsectors and components, is emphasized. This implementation should occur through state programs, particularly concerning the technical and technological aspects of agricultural production processes. Such measures promote the development of high-tech activities and facilitate the transition from a low-resource economy to a high-tech, innovative economy. The research results provide a comprehensive overview of existing AI technologies that have proven effective in solving problems within agriculture and agribusiness. These technologies are expected to advance significantly over the next five to seven years, allowing businesses to gain competitive advantages and achieve substantial economic benefits. The use of AI and robots in agriculture addresses several key challenges, including alleviating labor shortages, reducing the harmful impact of chemicals on humans and the environment, increasing crop yields, improving enterprise productivity, and lowering the costs of agricultural production. Future research may focus on a more detailed examination of various AI technologies and methods to identify their optimal applications across different areas of human activity, including agriculture and agribusiness. This will include exploring effective combinations of these technologies and establishing an optimal internal structure, encompassing both mathematical frameworks and software coding.

Approach and model for forecasting winter wheat yield using machine learning

A. Tryhuba , A. Zheliezniak , I. Tryhuba , A. Tatomyr — Fri, 20 Dec 2024 00:00:00 +0200

An analysis of the relevant subject area and scientific literature on the use of intelligent approaches for forecasting and planning activities in agriculture has been conducted. This analysis highlights the feasibility of employing machine learning to predict processes in agriculture. The purpose of this article is to develop a model for predicting winter wheat yields using historical data and machine learning algorithms, while taking into account the specific characteristics of processes and resource use in agriculture. The proposed forecasting approach for winter wheat yields relies on historical data and machine learning algorithms that consider the unique aspects of agricultural processes and the resources involved. The selection of an effective model for predicting winter wheat yield is based on a developed algorithm, which involves a systematic implementation of seven stages.

To prepare the data, the authors utilized intelligent analysis algorithms that assess the relationships between various factors affecting winter wheat yield. With qualitatively prepared data, the research substantiates the model for predicting winter wheat yield by evaluating its accuracy indicators. Three algorithms were chosen for the study: least squares (OLS), gradient boosting (XGBoost), and linear regression with polynomial features. Separate models were created for each algorithm and compared based on quality indicators. The findings indicate that the best model is the gradient boosting (XGBoost) model, which demonstrated the lowest values across all quality metrics - MSE, RMSE, MAE, and R-squared. Future research should focus on the development of an intelligent information system for planning agricultural processes, which includes a module for forecasting winter wheat yields based on the validated model proposed in this study.

Use of simulation modelling in decision support information systems

P. Lub , V. Smolinskyi , R. Padiuka , O. Boiarchuk , V. Stanko — Fri, 20 Dec 2024 00:00:00 +0200

The prerequisites for utilizing information technology (IT) in developing information and analytical tools to support decision-making in agro-industrial complex development projects are outlined. An analysis of current approaches to studying technological systems in a changing external environment, particularly through modeling methods and IT, has been conducted. The components of technological system projects and the impact of the project environment are identified. The factors contributing to the variability of external conditions affecting the technological processes of crop harvesting are discussed, along with the rationale for employing statistical simulation modeling methods. The importance of creating a set of models that accurately represent the components of the technological system for harvesting cultivated plants is emphasized. Key components of the external project environment that contribute to the probabilistic nature of the time frame required for task execution within the technological system are highlighted. Additionally, elements of the methodology for accounting for the influence of agrometeorological conditions on the time frame for work execution during the autumn months in sugar beet harvesting projects are illustrated through a statistical simulation model. Simulations have been performed, and their results are summarized. The application of correlation-regression analysis methods reveals patterns in the variations of the naturally allowed time frame compared to the planned start time for crop harvesting and establishes correlation dependencies. The relationship between the duration of the naturally allowed time frame for beet-harvesting tasks and the statistical characteristics of this duration for various calendar start dates has been determined. Furthermore, the differential functions of the distribution of the naturally allowed time frame for beet-harvesting work during the autumn season have been established.

Impact of using generative artificial intelligence on the productivity of software developers

O. Kovalyshyn , L. Chukhrai , N. Zaplatynskyi — Tue, 25 Feb 2025 00:00:00 +0200

The paper highlights that the creation and rapid implementation of generative artificial intelligence (AI) is becoming a driving force in the further development of technological progress. Analyzing the development of most industries, it can be asserted that its use helps many of them gain added value, as it helps to partially or fully automate a number of functions previously performed by hired employees. The most widespread use of artificial intelligence is observed in manufacturing, healthcare, security, and energy sectors. This indicates a redistribution of professions, where new roles emerge that are necessary for working with AI. These primarily include those who develop solutions using AI, particularly IT specialists and software developers. They use various AI tools - ranging from ChatGPT and Einstein GPT to H2O.ai and beyond.

The study examined how AI can enhance the productivity of software development teams, consisting of individuals with different roles performing various tasks that result in a collective outcome. The research was conducted using the results of software development specialists from SoftServe. Over 1,000 of its employees - programmers working in the company's branches located in seven different countries - participated in projects at various levels. After conducting the planned research, it was established that developers at SoftServe use generative AI to reduce the overall time for software product creation by nearly a third compared to those who did not use AI. The performance and achievement of planned results by the test group in the SDLC project were 45% higher than that of the control group.

Introducing AI into software development workflows improves the productivity of its executors. This is confirmed by the results of its use by C#/.NET Back-End engineers, where productivity increased by an average of 49 %, and the time to achieve the final result decreased by 33 % compared to those who did not use AI. These data demonstrate thagenerative artificial intelligence is beginning to play a significant role in the IT sector, particularly in software development.

Moreover, it was found that the effective use of generative AI reduces development time and increases productivity and helps reduce technical debt at the project implementation stage. Teams that integrated generative AI into their workflows reduced the number of code errors by 25%, which, in turn, contributed to improving overall product quality and reducing future maintenance costs. Thus, AI improves development processes and positively impacts the entire software lifecycle.

Influence of MIG brazing modes on welding parameters taking into account the synergistic effect of the semi-automatic welding machine

O. Shvets , S. Berezovetskyi , P. Koruniak , S. Baranovych , R. Sheremeta — Thu, 13 Feb 2025 00:00:00 +0200

In the technological processes of mechanical engineering, the method of brazing in inert gas using semi-automatic welding equipment is increasingly used for joining single and dissimilar materials. This method is also known as MIG brazing. Despite all its advantages, there are no clear recommendations for the operators of welding equipment regarding the choice of the operating modes of the equipment and their influence on the welding parameters.

The study of the MIG brazing process of 09Г2С steel with a Trans Puls Synergic (TPS) 2700 SMT semi-automatic welding machine from Fronius was carried out using a special copper-silicon CuSi3 wire with a diameter of 1.2 mm in a protective environment of pure argon with a welding column designed for linear welds, in order to identify the peculiarities of the influence of process modes and parameters on the shape and quality of the resulting joints.

As a result of the research, it was found that the process of MIG brazing of steel using a semi-automatic welding machine with Fronius TPS 2700 CMT has certain characteristics of setting technological parameters in different operating modes. The synergy of the power supply allows the main process parameters to be set within certain limits, depending on the selected operating mode.

The best MIG brazing quality is achieved when the semi-automatic machine is operated in Synergic and SMT modes. To weld steel sheets with a thickness of 1...3 mm in these modes, the welding current should be set in the range of 90...160 A at a wire feed speed of 3...5 m/min respectively. It was also found that by increasing the speed of the torch movement, the width of the weld decreases, and therefore the weld bulge increases.

As a result of the research, recommendations were made for the construction of a semi-automatic welding machine, taking into account the synergistic effect of its operation.

Methodological complex for determining cutting force during turning operations

S. Baranovych , R. Sheremeta , O. Shvets , S. Korobka , S. Syrotiuk — Thu, 13 Feb 2025 00:00:00 +0200

The work presents a comprehensive methodology for determining cutting force during turning operations. Reducing energy consumption in mechanical metal processing is crucial for optimizing production. Energy consumption can be measured directly or indirectly. To minimize the time spent measuring cutting force and other technological parameters, computer-based measurement and modeling methods can be employed. This assessment of necessary technological parameters in mechanical metal processing can be facilitated using virtual tools in the LabVIEW software environment developed by National Instruments. This software offers several advantages: it utilizes a visual programming language, features an intuitive user interface, allows for real-time use of external input/output devices, and provides robust data visualization tools that can display data in graphs, diagrams, and tables. Additionally, it supports various operating systems, including Windows, macOS, and Linux, making it versatile for use on different devices. The LabVIEW environment is thus proposed for determining the technological parameters of turning operations. The primary component of cutting force can be established by continuously inputting data from a torque dynamometer (DK1) that includes a hardware-software system for obtaining a digital signal of the measured quantities. Other components of cutting force can be estimated using analytical methods within the LabVIEW software. This approach enables research across a wide range of technological parameters in mechanical metal processing on turning-milling machines, while allowing for real-time visualization and analysis of the measured parameters on a PC.

Analysis and experimental determination of temperature parameters for the working fluid in an adjustable volumetric hydraulic drive for machines

M. Mykhaliuk , Ya. Sholudko , M. Babych , R. Humeniuk — Sun, 23 Feb 2025 00:00:00 +0200

The hydraulic system of the modern loader JCB 4CX Sitemaster Pro is examined. The influence of the working fluid temperature on the hydraulic drive power as a whole, and its dependence on the technical condition of the hydraulic system components, has been established. Calculations and studies have shown that new pumps with operational wear theoretically have different optimal working fluid temperatures. An analysis has been conducted on the issues of increasing the efficiency of the power manipulative hydraulic drive and mechatronic systems, as well as the hydraulic drive of agricultural machinery, vehicles, road construction equipment, and lifting equipment operating under harsh conditions. Promising directions for improving existing and creating new samples and models of power hydraulic drives for the aforementioned systems, installations, machines, and equipment are determined. The methods for increasing the efficiency of a variable displacement hydraulic drive using multiple displacement hydraulic motors have been considered. The research shows that the pressure loss in the supply line from the pump to the inlet of the hydraulic motor should be minimal. The proposed method for constructing constant hydraulic motor curves provides insight into the values of flow rate and maximum pressure developed by the pump unit. Methods for reducing energy are proposed: the flow parameter values should be selected as closely as possible to the values of the pump unit output. In case of design complexity, it is necessary to reduce energy losses due to throttling by using flow regulators and pressure valves.

Justification of the influence of the roller on the process of compaction of the combined method of field cultivation after harvesting corn

M. Korchak , A. Rud , S. Hrushetskyi , S. Zamoiskyi — Sun, 23 Feb 2025 00:00:00 +0200

With the proposed combined method of cultivating fields with corn plant residues, several processes are carried out in sequence, namely cutting long and coarse plant residues, distributing them in rows, compacting the materials, crushing the compacted plant-earth mass, and leveling the treated soil surface. Each step is designed to improve the effectiveness of the subsequent processes.

The proposed combined method suggests that after harvesting corn rollers perform a crucial technological function - compacting the cut and rolled stalks along the cultivation lanes. This step ensures a more efficient flow of the subsequent processes in the proposed method.

Theoretical studies were conducted to examine how the roller impacts the compaction of cut and rolled corn plant residues along the cultivation strips. These studies helped establish the roller's main technological parameters based on experimental data regarding field clogging with corn plant residues.

The key technological parameters of the roller include a diameter (D_k) of 0.20 to 0.24 meters and a width (B_k) of 0.20 to 0.25 meters.

A theoretically justified roller has been incorporated into the design of a combined shredder for corn plant residues. Further research is needed to optimize the compaction of stem residues and rollers that are used in combined tillage units for soil cultivation following corn harvest.

Experimental study of the influence of vibration load

Sun, 23 Feb 2025 00:00:00 +0200

Experiments were conducted to analyze the optimal characteristics of a vibro-impact type compactor for tamping hay and silage in the context of a peasant family farm. The goal was to establish the appropriate duration for compacting silage mass under various conditions and operational modes. When loading chopped plant material into silos or hay storage, it is essential to ram the material constantly. This ramming process ensures compaction and ventilation of the crushed mass, allowing for fresh air to circulate and preventing the material from overheating. Excessive temperatures can accelerate biochemical reactions, leading to a decline in feed quality and nutrient loss. To prevent overheating during the filling of storage, intensive tamping is necessary. The aim of this study is to investigate a lightweight, cost-effective, yet powerful and productive vibratory compactor for use in family farms’ silage preparation. The experiments were conducted while preparing hay from grain and fodder crops. The results obtained can be used to characterize the tamping process for traditional silage crops, such as cereals, legumes, and their mixtures. After analyzing the overall results of the experiments, several key findings were established:

- Optimal parameters for a compact vibrator suitable for small storage units have been identified.

- By using a vibration-impact type working body with parameters suitable for production conditions, it is possible to quickly achieve a residual density of the silage mass comparable to the average density found in tower storages during the storage process.

- The silage mass is compacted most efficiently during the first 10 to 30 seconds. This time frame can be considered optimal for tamping in one location using impact-type working bodies.

- In the process of tamping silage made from cereal grasses, a crank radius of 0.03 m, a pusher stroke frequency of 8 Hz, a tamping duration of 10 seconds, and a mechanism weight of 80 kg per square meter of the pusher shoe area resulted in a sample density of 377 kg/m³. This density can also be achieved by applying a static pressure from a load of 1200 kg per square meter over a period of 72 hours.

Study of physical and mechanical properties of Gala apple fruits

Z. Hoshko , V. Burtak , M. Mahats , O. Levchuk , T. Кokhana — Thu, 13 Feb 2025 00:00:00 +0200

This article focuses on the physical and mechanical properties of apple fruits that must be considered during post-harvest processing. Apples undergo various mechanical actions such as cleaning, transportation, sorting, storage, and processing. Therefore, designing and calculating equipment for these mechanical operations requires a thorough understanding of the fruit's technological properties, including size, weight, strength, and cutting force. Understanding the cutting force of fruit is essential for determining optimal and efficient parameters for the working components that crush the fruit. This knowledge is also vital for designing machines and equipment for the processing industry.

To address these needs, a program for experimental research has been developed, specifically aimed at determining the physical and mechanical properties of Gala apples. This variety is well-established in Ukraine and thrives in the Western regions. The research will focus on the following aspects:

- mass and dimensional parameters

- fruit density

- fruit cutting force

By analyzing the results of the experimental studies and the resulting curves, the authors can draw meaningful conclusions about the Gala apple variety.

- diameter d_min = 57 mm, d_max = 80 mm, d_average = 63 mm, V_coefficient _{of variation} = 7 %;

Study of the physical and mechanical properties of Lastivka variety beans

Z. Hoshko , V. Burtak , R. Barabash , T. Kohana , O. Berezovetska — Thu, 13 Feb 2025 00:00:00 +0200

This article focuses on the physical and mechanical properties of beans, which are crucial for their post-harvest processing. All grains undergo mechanical actions such as cleaning, sorting, transportation, storage, and processing, making it essential to understand the technological properties of the grain components (shells and kernels). To design and calculate the equipment for these mechanical operations, one needs to know the force required to break the shell and the kernel. This knowledge helps establish optimal parameters for the working components and is vital for the design of machines and devices used in the processing industry. To address these tasks, a program for experimental research was developed to determine several physical and mechanical properties of the Lastivka variety of beans. This variety is well-regarded in European countries and is commonly cultivated in the western regions of Ukraine. The research focused on measuring mass and dimensional indicators, the force required for destruction, and the modulus of elasticity.

The results indicate that the variations in size and mass of the Lastivka beans are minimal. By calculating the average number of plants per square meter, the number of pods per plant, and the number of grains per pod, one can easily estimate the expected yield of beans. However, the force required to destroy the seeds is relatively high and varies significantly, which can negatively impact processing, cleaning, and transportation. If the operational settings of the equipment are not correctly selected, it may result in the destruction of some seeds.

Theoretical research of the variable compression ratio mechanism in the rodless internal combustion engine

T. Kolesnikova , O. Lykhodii , T. Makhorkina — Fri, 20 Dec 2024 00:00:00 +0200

It has been established that one of the ways to improve the economic and environmental performance of internal combustion engines is to regulate the compression ratio in partial engine operation modes. To explore this, an analytical review of studies on the application of variable compression ratios in gasoline engines was conducted.

The review and analysis of the research on developing engines with variable compression ratios revealed that it is possible to improve both the economic and emission characteristics of gasoline engines by enhancing the combustion process during partial load operations through compression ratio regulation. Additionally, it was found that a promising design of an engine with a variable compression ratio is the connecting rod-free piston engine with a crank-slider power mechanism. In this engine, unlike other unconventional engines, the effective efficiency tends to increase as the compression ratio exceeds 14, thanks to the reduced dependency of the mechanical efficiency coefficient on load and rotation speed. Furthermore, in a connecting rod-free internal combustion engine, the implementation of compression ratio variation is simpler and more efficient, improving engine performance.

It is known that existing samples of engines with variable compression ratios have a low response speed of the compression ratio adjustment mechanism. This results in a significant amount of engine operation time under detonation conditions, reducing its reliability and durability. Therefore, studying the effect of the compression ratio adjustment mechanism design on the speed of compression ratio change depending on the parameters of the working process is a crucial area of research for developing engines with variable compression ratios. The study theoretically examined the impact of engine operating modes on the response time of the compression ratio adjustment mechanism. A mathematical model was developed to calculate the activation time of the mechanism, along with a methodology for selecting rational cross-sectional parameters of the hydraulic locks in the mechanism. The results of theoretical and experimental investigations of the compression ratio adjustment mechanism for a four-stroke gasoline engine are presented.

Stress distribution in a half-plane with a circular hole under tension at an angle to a straight edge

O. Ponomarenko , V. Semerak , O. Burnaiev , O. Havryliak — Fri, 20 Dec 2024 00:00:00 +0200

In modern industries such as project construction, aircraft manufacturing, shipbuilding, and machine engineering, thin elastic plates are commonly used. Depending on various factors, these plates feature different types of holes, which can lead to strain concentration when loaded near these holes. This concentration of strain can have an unfavorable impact on the durability of the component. The distribution of strains around the contours of the holes is uneven, leading to small sections that experience high strain levels. These critical sections are often where brittle cracks or plastic deformations develop, potentially resulting in structural failure.

Therefore, studying the distribution of strains near curved holes is essential from both theoretical and engineering perspectives. This work presents a solution to the problem of stress concentration in a half-plane with a circular hole, subjected to stretching at an arbitrary angle to a straight edge. The problem is approached by utilizing the main stress function, which corresponds to the stress state in the half-plane without the hole. A second biharmonic function is added to this function, accounting for the additional stress state introduced by the hole's presence. The task involves finding a biharmonic stress function that satisfies the boundary conditions along the contour of the hole, on the straight edge, and at infinity. The novelty of this research lies in its provision of insights regarding the impact of the edge orientation of the half-plane concerning the tensile load field on stress concentration. The solution is

presented in bipolar coordinates, and formulas for the stresses along the contour of the hole and on the straight edge are derived. The stress values obtained for various key points along the hole’s contour and the straight edge for specific cases provide a basis for establishing the coefficient of strain concentration near the holes. This information can be beneficial in engineering practices during the design and development of components in the aircraft, shipbuilding, and machine manufacturing industries.

Stress state of a transversally isotropic medium with a spheroidal inclusion under imperfect contact conditions

T. Bubniak , V. Semerak , O. Burnaiev , O. Ponomarenko , L. Shpak , O. Hovda — Fri, 20 Dec 2024 00:00:00 +0200

Spatial problems related to the theory of elasticity and thermoelasticity play a significant role in the modern mechanics of deformable solids. Their importance arises from the numerous applications of this field in addressing critical technical and technological challenges across various industries. Research in this area is primarily driven by the need to understand the strength of materials and structural components. Typically, extreme stresses occur at the phase interface zones, as nearly all structural materials exhibit heterogeneity in their composition. Modeling the properties of interphase boundaries while considering their actual structural features is a crucial task. To obtain reliable and comprehensive information about stress distribution in structural elements, effective analytical and numerical methods must be employed to tackle spatial problems within the theory of elasticity. In spatial problems pertaining to the theory of elasticity and thermoelasticity for transversely isotropic bodies, solutions are expressed through potential functions that are harmonic in specifically chosen coordinate systems. This approach significantly alleviates the mathematical challenges typically encountered when solving particular boundary value problems. Recent publications from both domestic and international researchers have addressed issues related to the theory of elasticity and thermoelasticity for isotropic materials, particularly under conditions of imperfect mechanical and thermal contact. For instance, the works of A. T. Ulitko, Yu. M. Nemish, and N. E. Kachalovska explore axiometric problems. However, there are limited solutions available for transversely isotropic bodies with inclusions of canonical forms. Unlike the analyzed problems involving perfect contact, the latter cannot be solved in a closed form but instead requires the resolution of infinite systems of linear algebraic equations. Notable advancements in this field have been achieved by researchers such as Ya. S. Pidstryhach and Yu. M. Podilchuk, who have constructed exact solutions for spatial problems related to elasticity and static thermoelasticity across various coordinate systems, including spherical, cylindrical, spheroidal, and parabolic configurations. The current study addresses the distribution of normal, meridional, and circular stresses in a transversely isotropic medium that contains an anisotropic inclusion shaped like a compressed spheroid, subjected to uniform all-around compression. This analysis depends on the geometry of the inclusion. Building on the solutions derived from spatial problems of elasticity and thermoelasticity involving a transversely isotropic medium with a compressed spheroidal inclusion, investigations were conducted into the thermal stress distribution within both the medium and the inclusion. This was done under the influence of arbitrary linear temperature and force fields. Engineering formulas were developed to calculate stress concentrations in both the surrounding medium and the inclusion under various mechanical loads, including compression, tension, shear, bending, and torsion.

Prospects for the reorganization of machine-building enterprises into large machine-building companies of Ukraine

S. Berezovetskyi , R. Humeniuk , O. Shvets , O. Berezovetska , P. Koruniak — Fri, 20 Dec 2024 00:00:00 +0200

The article focuses on the challenge of enhancing the competitiveness of Ukrainian machine-building enterprises, which is vital for equipping the national economy with modern production technologies. It emphasizes the necessity of producing high-quality machinery products to meet domestic demand and compete effectively in both national and international markets. An in-depth analysis of the current state of the industry identifies key factors that influence the production of high-quality products. The importance of organizational and technological aspects in fostering innovative development in machine building and promoting advanced production methods is highlighted. It has been determined that in-house manufacturing technology systems are the most effective for maintaining complete control over the entire product lifecycle, from development to disposal, which is crucial for achieving high-quality standards.

The historical analysis of machine building in Ukraine reveals challenges stemming from the breakdown of direct relationships between manufacturers and technology suppliers. It was observed that the introduction of centralized repair and maintenance services led to a decline in the efficiency of technical maintenance, which consequently reduced equipment effectiveness. The study has recognized that re-establishing direct production and technological links, along with the implementation of modern production organization methods, are essential for enhancing the efficiency and competitiveness of Ukrainian machinery products.

Moreover, it is crucial to follow the suggestions of experts focused on the development of machine-building enterprises, agriculture, and legislative regulations related to food supply and production diversification. The significance of government support for stimulating innovation and improving product quality is emphasized. The article stresses the importance of adopting programmatic approaches to ensure increased production responsibilities, advancements in machine technical specifications, and the development of technological systems to enhance the effective operation of the equipment throughout its lifecycle.

Enhancing the process of preparing parts for automotive equipment restoration

V. Kokhan , O. Honcharuk — Fri, 20 Dec 2024 00:00:00 +0200

The ongoing conflict between the Russian Federation and Ukraine has significantly altered the technological processes involved in preparing wheeled military automotive equipment for restoration, repair, and maintenance. This shift has been largely due to the loss of stationary repair stations, bases, and factories. An analysis of the existing military and civilian ultrasonic cleaning units, along with the technologies employed for soaking and cleaning fuel and running systems in vehicles, has highlighted several important aspects and shortcomings in their operational processes. These factors must be addressed in the development of new designs. Ultrasonic units are commonly used to clean heavily contaminated parts, such as fuel injectors, filters, pumps, and chassis components. Therefore, these units must meet the following requirements: cleaning efficiency, mobility, energy efficiency, reliability, ease of maintenance, safety of use, and considerations for safe operation in military conditions.

The authors propose a new technology for the surface preparation of parts using ultrasound for the mobile restoration and repair units of the Defense Forces of Ukraine. This innovative technology, combined with a patented universal unit, will fulfill several essential requirements, including:

- a compact and lightweight design for easy transportation and field usage;

- compatibility with standard power sources, allowing for both autonomous operation and connection to network power supplies (including generators and alternative energy sources);

- utilization of advanced ultrasonic technology for deep soaking and cleaning of fuel systems and chassis components;

- an intuitive interface that allows for quick setup and operation without the need for extensive training.

The universal ultrasonic unit, equipped with this new cleaning technology, will enhance the efficiency and quality of restoration tasks, significantly reducing the time required to repair automotive equipment in combat

conditions. This is particularly vital for units involved in maintenance operations in the field.

Аssessment of refrigerator vehicles suitability for the transportation of perishable goods

O. Myroniuk , R. Paslavskyi , O. Sukach , V. Shevchuk — Fri, 20 Dec 2024 00:00:00 +0200

The factors influencing the selection of motor vehicle rolling stock for transporting various types of cargo are examined. The focus is on modern logistics approaches for delivering products to the retail trade network using specialized rolling stock. It was found that the temperature conditions during the operation of refrigerated vehicles on delivery routes are often not maintained due to the frequent opening of the van doors. This can result in a loss of quality for perishable goods during transit. The primary factor negatively impacting this is the temperature of the surrounding air. An expression of the heat balance inside the cargo compartment of a refrigerated vehicle is presented, revealing the components of heat loss. Key opportunities to reduce heat loss in refrigerated vehicles, which ensure the preservation of cargo quality, have been identified.

The design features and technical specifications of specialized vehicles for transporting perishable goods, along with their refrigeration units, have been clarified. An experimental investigation was conducted to study the effect of ambient air temperature and unloading time on the air temperature inside the cargo compartment of refrigerated vehicles equipped with compressor and eutectic refrigerating units. The hypothesis that ambient air temperature has a linear effect on the air temperature in the cargo compartment was confirmed. Analytical relations were established for the air temperature in the cargo compartment of various types of refrigerated vehicles, based on ambient air temperature, unloading time, and transit duration with cargo. Recommendations have been made to select the most suitable rolling stock for transporting small batches of ice cream on delivery routes in the trade network of Lviv. It was determined that IVECO vehicles are more appropriate for transporting small batches of perishable goods on delivery routes that involve frequent stops and high ambient air temperatures. This choice will help preserve the quality of the cargo and increase the operational efficiency of the specialized rolling stock.

Comparative analysis of the methods of agro-ecological assessment of machine-tractor units in Ukraine and EU countries

P. Syvulka — Fri, 20 Dec 2024 00:00:00 +0200

The article focuses on a comparative analysis of the approaches, methods, and regulatory frameworks for agro-ecological assessment of machine-tractor units (MTU) in Ukraine (the Eastern School) and EU countries (the Western School, specifically using Germany as an example). There are significant differences related to the increasing use of heavy tractors classified between 3 and 6, which raises urgent concerns about soil compaction and degradation in agricultural lands. This situation highlights the necessity for the development of a national framework in Ukraine that aligns with EU standards. One major issue identified is the ambiguity surrounding the use of specific wheel pressure as the sole regulatory indicator for the agro-ecological assessment of MTUs. Additionally, there is a lack of a national regulatory framework for the rapid assessment of the physical and mechanical properties of various soils, such as the use of penetrometers that align with EU practices. Other factors that need consideration include the varying sizes of front and rear axle wheels and the compaction caused by the rear axle during travel on a single track.

The article proposes harmonizing the national regulatory framework with EU practices through the adoption of relevant ISO standards as the national standard (DSTU). Furthermore, it offers suggestions for improving the agro-ecological assessment of MTUs by considering the sequence of wheel passage for front and rear axles, the different sizes of front and rear tires, and the effects of mounted and trailed implements.

The need for ongoing development and enhancement of methods for studying and evaluating soil compaction is emphasized, particularly during the sequential passage of wheels from the front and rear axles. This includes assessing the impact of mounted and trailed implements on load redistribution along the axles, analyzing how wheel size variations affect compaction, and monitoring the frequency of wheel passage.

Assessment of occupational risk of workers during maintenance and repair of electrical equipment.

Fri, 20 Dec 2024 00:00:00 +0200

At electric power enterprises, electrocution accounts for the largest share of fatal accidents, representing 55% of all deaths caused by electric shock. Most electrical injuries occur during the operation of external electrical installations, which make up 53% of incidents. This includes transformer substations, overhead power lines, and capacitor and converter devices. The most hazardous professions in these enterprises are electrical fitters responsible for repairing electrical equipment. Consequently, identifying risks and dangerous factors during the operation of electrical equipment is a critical task for preventing industrial injuries. The risk of hazardous situations can be assessed by combining the severity of potential consequences with the likelihood of occurrence during production activities. An analysis of professional risks and the main types of threats in the repair and maintenance processes of electrical equipment has been conducted. It was found that the basic risk level of electrocution due to deficiencies in an electrician’s work permit or violations of safety requirements is 48 points, which indicates an average risk level. This level suggests that the risk is unacceptable without implementing protective measures. Additionally, the risk level due to inadequacies in providing tools, protective clothing, and other personal protection equipment, as well as any malfunctions of such equipment, is rated at 54 points, indicating a high risk. Based on the results of the risk assessment during the operation of electrical equipment, the adequacy of planned safety measures can be evaluated. This assessment helps determine whether improvements are needed or if other safety measures should be introduced. To reduce the likelihood of traumatic situations and associated losses, appropriate safety measures are planned. These range from the complete elimination of hazards at the workplace to the requirement of using personal protective equipment.

Assessment of the adequacy of the simulation model of universal towing vehicles

H. Khudaverdian , O. Sukach — Fri, 20 Dec 2024 00:00:00 +0200

The article discusses the results of an experimental study aimed at determining the maximum tractive effort that a wheeled vehicle (WV) can exert on a deformable surface. The primary objective is to validate a previously developed simulation model for WV movement, based on the WES methodology of the US Army, using the MATLAB Simulink software environment. Specifically, this involves evaluating the software module designed to compute maximum tractive effort for its adequacy. Previously, the adequacy of this model was assessed by comparing experimental data from the T-150K wheeled tractor with results from the corresponding simulation modeling conducted with the aforementioned software module. The experimental assessment of tractive effort was performed using the light impact vehicle "Mamai" and the Mahindra Feng Shou FS244 minitractor having well-documented technical and operational specifications. The study adhered to the principles of the WES methodology, specifically its "goes/does not" criteria, which is fundamental to the construction of the simulation model. The article details the necessary data structure for comparing experimental and modeling results and specifies the types of data and their sources to facilitate further evaluation of the model's adequacy. It also outlines the measuring equipment used in the experiments, including the modified LAN-M PRO soil penetrometer for assessing the cone index (CI) of the deformable surface, the DPU-2-2-U2 dynamometer for measuring traction force, and the UNI-T UT373 laser non-contact tachometer for determining the actual wheel rotation frequency. Confirming the adequacy of this simulation model will enable its application in the development of universal traction vehicles in the Unimog/Avtotrak category (N1/T1 type) during the design phase. This will assist in selecting power drive units and determining traction class, as well as in choosing appropriate technological equipment and trailers. The results of the experiment indicate that the simulation computer model of the WV movement is, in fact, adequate.

Methodology of the simulation modeling of maintenance technological processes

R. Barabash , A. Sharybura , V. Chukhrai , M. Mykhaliuk — Fri, 20 Dec 2024 00:00:00 +0200

The proposed technique takes into account various structural features of TP maintenance, such as restrictions on the sequence of operations and the arrangement of work areas within the service facility.

The modeling process establishes conditions for ensuring: 1. the implementation of key theoretical principles regarding the interdependence of different parameters involved in maintenance operations, including the maintenance front (f), the number of workers (u), and the equipment types (Kr). It also considers the interdependence of various indicators related to maintenance efficiency, such as the duration of the technological process (T_T.P) and the utilization coefficients for labor (ƞ_u) and equipment (ƞ_r); 2. automated calculation of parameters and performance indicators related to maintenance efficiency and technical-economic metrics; 3. the generation of initial data required for synthesizing parametric series of production structures with varying productivity levels, thereby determining maximum and optimal productivity.

An automated design system has been developed within the NetBeans IDE environment for simulating the maintenance and repair of cars, tractors, mobile machinery, and their hydraulic systems. The initial data for modeling include the number of maintenance tasks (ETOs) and their characteristics, the work areas where these tasks are conducted, types of equipment, time norms for operations, and the priority of executing specific tasks. The aim is to find the minimum time (T_T.P) required to complete N operations, given a distinct production and technological structure. This algorithm facilitates the creation of an operation schedule that minimizes the duration of the technological cycle while maximizing the utilization rates of workers and equipment. This scheduling must adhere to several constraints: first, only one operator and one type of equipment can perform an operation in a given work area at the same time, meaning that operations located within the same work area cannot be executed in parallel; second, the distribution of operations among performers and equipment must maintain the integrity of time and operational connections; and third, efforts should be made to minimize the loss of workers' time as they move around the site and between work areas.

The described algorithm is capable of conducting numerous random simulations to generate different solutions. Each solution varies because a uniform random variable generator is utilized to select the operations for execution.

Innovative GIS-technologies in agriculture based on the automated platform EOSDA CROP MONITORING

O. Berezovetska , A. Sharybura , O. Krupych , S. Berezovetskiy — Sun, 23 Feb 2025 00:00:00 +0200

Innovative GIS technologies based on the EOSDA Crop Monitoring automated platform play a key role in the modernization of agriculture, providing the ability to quickly collect and analyze field data. This information is gathered not only from traditional ground installations but also through satellite monitoring and drones, facilitating accurate assessments of field conditions, plant health, and climatic factors.

One of the primary applications of this data is yield forecasting, which empowers farmers to strategize in advance. This proactive approach reduces the risk of losses and optimizes resource utilization. GIS-based precision farming technologies enable the precise regulation of fertilizers and plant protection products in specific areas of the field, thereby enhancing farm efficiency.

Furthermore, the EOSDA Crop Monitoring platform provides tools for tracking livestock movements and populations, which is essential for managing large agricultural operations. By integrating satellite data with information from various enterprise sources, the platform achieves short-term financial outcomes and supports long-term sustainable development goals within the agricultural sector.

The platform features an intuitive interface, making these technologies accessible to small farms. The adoption of innovative GIS technologies helps assess risks linked to climate change, pests, and plant diseases. Additionally, accurate dosing of fertilizers and pesticides minimizes their usage, improving soil quality. Integrated decision support

systems offer recommendations to optimize agronomic practices. Collaboration among stakeholders in the agricultural sector is crucial, as it encourages joint development and knowledge sharing.

Analysis of existing designs and formation of a hybrid drive scheme for wheeled off-road vehicles

A. Kikhtan — Sun, 23 Feb 2025 00:00:00 +0200

The hybrid drive is already an essential feature of the new fourth-generation wheeled and tracked military vehicles (MVs). However, the conditions for off-road use and the primary goals of employing a hybrid drive - such as minimizing sound and reducing infrared signatures to avoid detection by enemy thermal imagers - differ significantly from those of conventional hybrid vehicles designed for general purposes. Additionally, in field positions, a vehicle with a hybrid drive can serve as a source of exported electricity to support units when stationary power networks are unavailable.

Driving in off-road conditions imposes specific requirements on the hybrid drive's characteristics. Resistance to movement increases considerably, necessitating a higher electric-only range when the internal combustion engine is not in use, as well as a larger battery capacity to meet these demands. Furthermore, engineers must account for the capability to traverse water obstacles up to 0.8 to 1.2 meters deep, which imposes additional design constraints on the electric drive system.

As a result, these factors heavily influence the design and technical specifications of the drive, which are only now being developed, lagging behind the designs of conventional hybrid vehicles. The limited availability of public information regarding the schematics and technical details of hybrid drives in military vehicles prompted an analysis of existing patents from leading automotive manufacturers, as well as published tests and evaluations of specific models. This investigation provided valuable insights into drive schematics.

The survivability of military vehicles is crucial; they must maintain mobility despite failures in either the electric traction drive or the internal combustion engine. Accordingly, two patent-free versions of drive schematics have been developed for prospective national military vehicle models, which are also applicable to the agricultural and other sectors of the economy. These two drive schemes are currently in the process of being patented.

Study of grip and rolling resistance coefficients of automobile tires

R. Shevchuk , O. Sukach , O. Myroniuk , V. Shevchuk , Yu. Habriiel — Sun, 23 Feb 2025 00:00:00 +0200

Determining the traction and traction indicators of cars, such as the coefficients of rolling resistance and traction, often uses a towing method. This method can be implemented with a simple device that includes a horizontally positioned dynamometer and a flexible towing belt. However, this approach is characterized by significant inaccuracies in measuring the average towing force. This inaccuracy arises from the variability in how the wheel drives interact with the supporting surface, which consequently affects the precision of determining both the grip coefficient and other traction-related indicators, including the rolling resistance coefficient.

The standard towing device used to evaluate the traction-coupling properties of mobile energy vehicles has a considerable elementary measurement interval (∆tdi). This interval is limited by the observer's ability to visually record the current readings from the dynamometer. The large elementary interval leads to low accuracy in determining the towing force, and consequently, the average values of force, rolling resistance coefficients, and grip. Rapid changes in the dynamometer readings, due to fluctuations in the road's micro-profile, further complicate accurate measurements. Therefore, relying on visual observation during these tests is highly imprecise.

To enhance the accuracy of determining the towing effort for mobile energy vehicles, a methodology and software complex have been developed. This improvement is achieved by reducing the elementary interval for recording measurement values. The proposed software module connects to the electronic dynamometer's power tension link. This module is designed as a microcircuit equipped with an analog-to-digital converter, which interfaces with a microcontroller and a bus for connecting external devices, along with a data output interface. This configuration ensures the efficient transfer of data to electronic storage media, such as a memory card or a personal computer.

The coefficients of rolling resistance and adhesion for Debica Passio 2 175/70 R13 82T wheels on the ZAZ Sens car were measured across various types of supporting surfaces. For an asphalt road, the grip coefficient (φi) ranged from 0.6914 to 0.7162, with an average value of 0.698. On a dirt road, φi values ranged from 0.5754 to 0.6144, averaging 0.595. For gravel surfaces, the values were between 0.3755 and 0.4451, averaging 0.408. The lowest φi values were observed on a wet dirt road, ranging from 0.3275 to 0.3767, with an average of 0.358.

For winter tires, the adhesion coefficient on an asphalt road (φi) ranged from 0.6138 to 0.6514, with an average value of 0.6280. On a dirt road, this coefficient was between 0.5799 and 0.6045, averaging 0.5919. For gravel surfaces, the values ranged from 0.3847 to 0.4041, with an average of 0.3945. Comparatively, with summer tires on a wet dirt road, the φi values were from 0.3761 to 0.3908, averaging 0.3825.

Mobility and controllability of off-road vehicle movement: formation of a regulatory framework

T. Krainyk , S. Kovalyshyn — Sun, 23 Feb 2025 00:00:00 +0200

A review and analysis of the methods and regulatory frameworks used by advanced countries concerning the requirements and evaluation of vehicle mobility – specifically maximum movement speeds and controllability - has been conducted. This assessment primarily focuses on military vehicles (MVs), while vehicles used in agriculture and forestry, such as dump trucks and timber trucks, are often modified forms of these all-wheel-drive MVs. One critical requirement in this field is compliance with agroecological standards, particularly regarding the permissible pressure exerted by tires on the soil, depending on agroecological conditions. Variations in the heights of off-road obstacles create specific demands for the suspension systems and steering kinematics, thereby affecting the controllability and stability of the vehicles. The greater amplitudes of suspension movement encountered off-road require the development of corresponding kinematics in the steering system, particularly under maximum alignment conditions. High-speed driving on unpaved surfaces is constrained by acceptable vibration loads on the driver, which differ significantly from those experienced on paved roads.

This study also developed a method for experimentally evaluating the mobility of off-road vehicles, along with proposals for establishing a national regulatory framework that aligns with the UN/ECE rules for the certification of vehicles intended for operation on paved roads.

Analysis of transient processes in a part of the ultra-high voltage electrical network that contains shunt reactors

V. Levoniuk , T. Muchailovich — Sun, 23 Feb 2025 00:00:00 +0200

The article examines scientific publications related to the study of transient processes in electrical network elements, particularly focusing on long power lines with distributed parameters and shunt reactors during both normal and emergency operation modes. The analysis indicates that while the research on transient processes in long power transmission lines is pertinent, there is still insufficient exploration regarding those processes associated with shunt reactors. Using a generalized interdisciplinary modeling method, which modifies the integral Hamilton-Ostrogradski variational principle, a mathematical model of a portion of the electrical network has been developed. This model primarily includes long power lines with distributed parameters and incorporates air chokes. The model is presented in a single-line representation. The mathematical model is based on the equation of a long line with second-order partial derivatives. To address this equation, the Neumann and Poincaré boundary conditions are proposed. The object model was implemented through numerical methods by discretizing the line equations using the straight line method. The voltage at the fictitious node of the power transmission line was calculated, and its behavior was illustrated. A program was written in the Visual Fortran programming language based on the developed mathematical model, which facilitated numerical experiments. With this model, electromagnetic transient processes in the power system were analyzed under the condition of a symmetrical three-phase fault. The results of the computer simulation are presented in the form of diagrams that have been thoroughly analyzed, alongside recommendations for potential users.

Study of voltage deviation from the nominal value in the electrical supply systems of the enterprise

D. Hrechyn , I. Drobot , M. Hoshko , O. Kakula , V. Filipovych — Sun, 23 Feb 2025 00:00:00 +0200

The quality of electricity refers to how closely the actual values of electrical parameters align with the values specified in GOST 13109-97. This study focuses on voltage deviations, which have normal values of +5% or -5% and limit values of +10% or -10%, according to GOST 13109-97. The power of the power source influences voltage fluctuations in the network, the power lost during transmission, and the power consumed by electrical equipment. Asynchronous motors are among the most common consumers of electricity, and their power consumption is proportional to the square of the voltage. This means that losses are significantly higher when voltage decreases. A drop in voltage leads to a decrease in the motor's rotational speed, which increases slippage. Additionally, current increases, efficiency declines, and insulation deteriorates faster. Lower voltage also negatively impacts the motor's starting torque and mechanical characteristics.

In electrical equipment, voltage losses result in reduced power, increased time for technical and production processes, and ultimately a decline in productivity and product quality. Furthermore, a decrease in voltage adversely affects lighting, as the luminous flux is directly related to voltage levels. While an increase in voltage enhances lamp efficiency, it can also shorten the lamp's service life.

The efficiency of converting electrical energy into other forms is partially influenced by the quality of the electricity itself. Research on electrical networks, power losses, oscillatory processes, and voltage levels continues to be relevant. Modern research methods frequently employ modeling techniques.

This work addresses significant issues associated with the operation of the company's power grid. Advances in

research and analytical methods have led to impressive results across various fields. In particular, MATLAB/Simulink software facilitates the analysis of power network operating parameters under different conditions.

The article presents a model of the company’s power supply system constructed in the MATLAB/Simulink environment. A study of the power supply system's operation was conducted using this model. The simulation covered load variations from 0.2Sn to 1.2Sn. The investigation focused on voltage deviations at different circuit points from the nominal value across three scenarios: when the transformer’s transformation ratio is 10/0.4 kV, with values of 400 V, 400•1.025 V, and 400•1.05 V.

Analysis of the results indicates that the system has been designed satisfactorily, as most deviations remain within the maximum allowable limits. However, to achieve more precise compliance with the voltage level, voltage on the transformer can be adjusted by switching the winding, or alternatively, by increasing the cross-section of the power wire in the first line.

Justification of the choice of the electric drive control system for pump unit of water treatment and water conditioning based on computer modeling

Sun, 23 Feb 2025 00:00:00 +0200

This article addresses the enhancement of the control system for the electric drive of the pump in the water treatment system used at a sugar factory. The study focuses on a flow diaphragm electrolyzer with a power consumption of 5 kW and an anolyte productivity ranging from 4.5 to 5 m³/h, examining the operation of an industrial water treatment system. Utilizing established calculation methods, the analysis compares throttle control and frequency control for the electric drive of the pumping unit. Key parameters, including consumed power, efficiency factor, torque, and shaft rotation speed, are calculated as functions of water flow while maintaining a specified pressure. The efficiency coefficients for the installation under different control methods are calculated, demonstrating the energy advantages of the frequency control method for the pumping unit. It was observed that, in frequency control mode, an increase in the hydraulic resistance of the system results in reduced electricity savings. A nonlinear MathCAD model was employed to evaluate an asynchronous motor starting directly under a fan torque and static load. The simulation results indicate that during the startup of the pump's asynchronous drive, the motor quickly reaches its nominal operating mode; however, the torque exhibits continuous pulsations. A mathematical model of the automatic control system allowed for a comparison between open and closed systems. Analysis of the resulting Nyquist diagrams, along with amplitude-frequency and phase-frequency characteristics, revealed an enhancement in operational stability for the closed system. Further simulations were conducted evaluating the performance of P-, PI-, and PID-regulators. Initially, all configurations provided effective stabilization; however, P- and PI-regulators eventually led to unstable operations. In contrast, the system utilizing a PID controller, with appropriately selected parameters, achieved a transient response lasting approximately 0.2 seconds.