Engineering

ASSESSMENT OF THE IMPACT OF VIBRATION LOAD ON MILLING MACHINE OPERATORS IN PRODUCTION CONDITIONS

Artiukh S. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-01

The article presents the results of a study of the impact of vibration load on milling machine operators in real production conditions. The relevance of the topic is due to the growing technogenic load on employees of machine-building and metalworking enterprises, where the intensive use of milling equipment is accompanied by the impact of harmful physical factors, in particular local and general vibration.

The aim of the study is to quantify the levels of vibration load and analyse its impact on the functional state of the workers' body. The study used instrumental methods of vibration measurement in accordance with DSTU ISO 5349, as well as a questionnaire survey of operators and an assessment of complaints about vibration discomfort. To ensure an objective study of the impact of vibration load on the body of milling machine operators, a series of instrumental measurements of local vibration parameters at workplaces was carried out. The measurements were carried out using a three-axis vibrometer at the control points of contact between the operator's hands and the equipment elements. The assessment was based on the vibration acceleration normalised by the root mean square value.

The results of the study showed an excess of permissible levels of local vibration at a number of work points, which can contribute to the development of vibration sickness and a decrease in performance. A number of preventive measures have been proposed, including technical modifications of equipment, regulated working conditions and the introduction of personal protective equipment.

The data obtained can be used to optimise working conditions, develop production control programmes and occupational risk management systems at industrial enterprises.

DIAGNOSTICS AND CONDITIONS FOR INCREASING THE EFFICIENCY OF THE GRINDING PROCESS BASED ON ENERGY PARAMETERS

Novikov F.V. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-02

The aim of the work is to create a new theoretical approach to the diagnostics of the grinding process based on the separation of the share of friction energy of the grinding wheel with the processed material from the total energy balance of the grinding process and to establish under these conditions the directions for increasing its efficiency. For this purpose, the work establishes analytical dependencies for determining the energy parameters of the grinding process: the conditional cutting stress (processing energy intensity) and the grinding coefficient (the ratio of the tangential and radial components of the cutting force), which are inversely related to the conditional shear angle of the processed material. Based on this, calculations have proven that by reducing the experimentally established tangential component of the cutting force, it is always possible to achieve equality of the values of the conditional shear angle of the processed material, which are determined by the conditional cutting stress and the grinding coefficient. Fulfillment of this condition ensures separation of the friction energy fraction of the grinding wheel with the processed material from the total energy balance of the grinding process, which is new in the theory of material processing by cutting. Calculations have established that during diamond spark grinding the friction energy fraction takes on a virtually zero value, since, due to the action of electric discharges in the cutting zone, a high cutting ability of the diamond wheel on the metal bond is ensured and its friction with the processed material is eliminated. A virtually zero value of the friction energy fraction was also obtained under the conditions of microcutting with a single diamond grain. All this indicates the reliability of the theoretical approach to the diagnostics of the grinding process proposed in the work.

It was also established that under the conditions of conventional abrasive grinding, the share of friction energy can exceed the share of "clean" cutting energy. This is due to the low cutting ability of the abrasive wheel, since a significant part of the abrasive grains work only in the friction mode with the processed material. It is shown that the calculated values of the friction coefficient and the grinding coefficient ("clean" cutting) differ little and actually correspond to the values of the known ratio of the micro-cut thickness to the radius of the abrasive grain tip, at which the chip formation process in the cutting zone almost does not occur. In these cases, it is important to use effective methods of dressing and impregnation of grinding wheels, effective technological environments to increase their cutting ability. Therefore, knowledge of the actually established values of the friction coefficient and the grinding coefficient ("clean" cutting) based on the proposed theoretical solution opens up new technological possibilities for increasing the efficiency of the grinding process and creating high-performance technological processes for processing machine parts.

ANALYSIS OF THE DESIGN OF DOMESTIC UNDERGROUND CARRIAGE BOGIES IN THE CONTEXT OF MODERN TRENDS IN THE DEVELOPMENT OF CARRIAGE BUILDING

BIRIUKOV S. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-03

The article deals with the design of bogies for electric rolling stock cars operated on domestic subways. The main components of bogies of different types are considered: models of the old design, which are used in the Kharkiv subway, and more modern ones, which are produced at PJSC ‘Kryukiv Carriage Works’ and are used on the cars of the capital's subway. According to the analysis, the design features of modern trolleys were identified, including the use of a sheet metal frame, which increased the strength and reliability of the structure. An important step forward was the introduction of an asynchronous traction drive, which provides better traction characteristics and energy efficiency. Safety systems have been improved by the use of a disc brake, and passenger comfort has been greatly enhanced by the use of air springs in the central suspension.

The paper also analyses various technical solutions used in the design of bogies in foreign subways, primarily those that differ from the classical vision of the rolling stock chassis, such as the use of non-traditional materials, such as carbon fibre, in the bogie's bearing structure or the use of wheels with rubber tyres instead of traditional steel ones.

The article compares the main operational characteristics of domestic bogies and a foreign analogue of Siemens, which has a similar design. It is pointed out that the design of modern bogies is promising in terms of improving traffic safety, efficiency and comfort of transportation, as well as the need to develop domestic car building.

ENVIRONMENTAL SAFETY OF TRENCHLESS TECHNOLOGIES

Suponyev V. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-04

The article provides an analysis of modern trenchless technologies for the construction of communication networks, which include pipelines for water and energy supply, electrical cables and communication cables. Since trenchless laying of communications involves creating a cavity in the soil, the relevant technical means and processes that occur in this process were reviewed.

Due to the fact that the purpose of the environmental expertise of works production projects is to minimize anthropogenic and technical impact on the environment, preserve and improve their properties for the sake of human health, the purpose of the article was to identify the features of these technologies from the point of view of environmental safety. The paper analyzed the current standards and requirements for environmental safety for each standardization object separately. Namely: protection of water resources, protection of the air basin, protection of the quality and properties of soils.

Considering that earthworks are associated with a significant loss of crop yields, an additional assessment of the impact of soil structural changes on the yield was made when creating wells in the soil by radial compaction. Relevant conclusions and practical recommendations for trenchless laying of underground communications were made.

Trends in the development of modern construction technologies are moving towards trenchless methods of construction work, which have their own characteristics and impact on environmental safety. Consideration of modern trenchless technologies from the point of view of environmental safety is a relevant issue.

THE ROLE OF INTEGRAL QUALITY CRITERIA IN THE ASSESSMENT OF AUTOMATIC CONTROL SYSTEMS FOR COMPLEX ENERGY FACILITIES

Fursova T.M. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-05

The article examines the specific features of applying integral quality criteria to evaluate automatic control processes in energy systems. These complex technical systems are characterized by increased requirements for accuracy, stability, and energy efficiency, where the quality indicators of transient processes directly affect the reliability of equipment operation and the efficiency of technological processes. Traditional assessment methods based on solving differential equations or conducting a detailed analysis of transient characteristics are labor-intensive and insufficiently suitable for rapid diagnostics, which highlights the relevance of using integral criteria as simpler and more universal indicators. The study provides a systematic analysis of the most widespread integral criteria, including linear, quadratic, and generalized ones, and determines their applicability for evaluating different types of transient processes. The linear criterion is considered the simplest tool for rapid estimation of oscillation damping; however, its limitations in cases involving sign-changing control error and oscillatory dynamics are emphasized. The quadratic criterion eliminates this drawback and allows one to assess the energy component of deviations, making it effective for optimizing automatic control systems and comparing their economic efficiency. Generalized integral criteria based on quadratic forms of the state, which are widely used in optimal control tasks, are also examined. It is demonstrated that minimizing integral criteria does not always guarantee the achievement of the desired transient response, particularly regarding the degree of oscillation and steady-state behavior. Therefore, the study substantiates the feasibility of combining them with additional quality indicators, which prevents incorrect assessments and ensures a comprehensive approach to the analysis of automatic control system performance. The obtained results confirm the high practical value of integral criteria as a tool for fast and informative monitoring of control quality in energy and industrial systems.

IMPROVING THE QUALITY PERFORMANCE OF HIGH-POWER ELECTRIC POWER PLANT PUMPS THROUGH OPTIMIZATION OF AUTOMATIC CONTROL SYSTEMS

Drozd V. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-06

The article examines the problem of improving the quality performance of high-power pump units at electric power plants through the optimization of automatic control systems. High-power pumps (over 1 MW) are critical components of the energy infrastructure, ensuring the operation of circulation, feedwater, and cooling circuits. Instability of their functioning, prolonged transient processes, and excessive dynamic loads lead to reduced energy efficiency, increased operational costs, and shortened equipment lifetime. The relevance of the study is determined by the need to improve control algorithms in order to ensure stable and efficient pump operation under variable loads and stringent reliability requirements.

The paper presents a mathematical model of a high-power pump, which includes head-flow, energy, and power characteristics, as well as second-order dynamic equations describing the interaction between the pump and the electric drive. Based on simulation, the influence of PID controller parameters on system dynamics is investigated, and integral quality criteria (ISE, IAE, ITAE) are evaluated. The obtained results demonstrate significant reductions in overshoot, shorter transient response times, and a decrease in integral errors by a factor of 1.7–7 when applying optimized controller settings compared to non-optimized ones.

Head, energy, and power characteristics of a real 2000 kW pump are constructed, along with transient response plots and energy performance diagrams for different control modes. A comprehensive quality index combining dynamic and energy-efficiency criteria is proposed. The results confirm the effectiveness of PID controller optimization and can be used for modernization of pump control systems at power plants to enhance their reliability and energy efficiency.

IMPROVING THE PERFORMANCE INDICATORS OF SMALL HYDROPOWER PLANTS THROUGH OPTIMIZATION OF CONTROL SYSTEMS

Мezerya А. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-07

The article addresses the problem of improving the comprehensive quality indicators of small hydropower plants by optimizing the automatic control systems of hydroelectric generating units. It is shown that, under conditions of increasing penetration of decentralized energy sources and heightened requirements for energy efficiency, the quality of dynamic processes occurring during load changes in small HPPs becomes particularly important. To solve this problem, an approach is proposed for optimizing the parameters of a PID controller within the automatic speed regulation system of a hydroturbine, based on modeling its dynamics as a second-order system with typical hydraulic and electromechanical time constants. A model of a small-capacity Francis turbine with nominal parameters – net head of 74 m, discharge of 2.05 m³/s, and nominal output of approximately 1.28 MW – is used as the research object. Generalized head, efficiency, and power characteristics of the turbine are presented. Simulation studies of the turbine’s response to step load changes were carried out for two configurations of the PID controller: non-optimal and optimized. A quantitative assessment of transient quality was performed using integral error- and time-based criteria, as well as energy efficiency indicators, including the relative loss of generated energy during the transient mode. It is demonstrated that optimal PID tuning significantly reduces the amplitude and duration of oscillations, accelerates the establishment of steady-state conditions, and decreases energy losses from 12.9% to 2.1%. A comprehensive quality index is proposed, integrating dynamic and energy criteria, which can be used as a universal metric for comparing different control strategies. The obtained results confirm the feasibility of optimizing control systems as one of the most effective ways to enhance the performance and reliability of small hydropower plants.

ANALYSIS OF THE REGULATORY BASE FOR ENSURING HIGH PERFORMANCE QUALITY INDICATORS OF PUMPS OF DEEP PUMPING STATIONS

Kanjuk G. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-08

The article analyzes the current regulatory framework of Ukraine on the issue of ensuring high performance quality indicators of submersible pumps used in the oil production industry. It has been established that one of the effective methods of improving the quality indicators of submersible pumps is the improvement of the regulatory framework aimed not only at determining the necessary indicators, but also at their guaranteed support during operation in the entire range of possible operating modes. It was determined that submersible pumps are used in more than half of the entire fund of oil and gas production enterprises. Therefore, submersible pumps are one of the most important components of modern systems in the oil production industry. It has been established that the technical condition of pumping installations largely determines the quality indicators of oil enterprises, the instability of pumps and, moreover, their failure can lead to significant losses and other negative consequences. It has been proven that ensuring high efficiency and reliability of deep pumps is one of the most important tasks in the direction of creating stable, reliable and highly economical functioning of oil production complexes and ensuring the minimum possible energy losses for oil production (reducing the cost of oil production). From the analysis of the regulatory support of Ukraine, it was concluded that the existing regulatory documents sufficiently fully regulate the general issues related to the terminology and basic provisions of the design and operation of deep pumps and oil production complexes where they work. There are useful methods for the creation and operation of automatic control systems for submersible pumps and methods for conducting relevant measurements, but the regulatory base does not fully reflect the methods for determining and improving some indicators of the quality of operation of submersible pumps, there is a lack of regulatory documents that regulate the provision of high technical quality indicators of submersible pumps during their automatic control, there is a lack of methods for determining and maintaining energy-efficient modes of operation of submersible pumps in a wide range of normal operation in real time.

ANALYSIS OF THE REGULATORY BASE FOR ENSURING HIGH INDICATORS OF THE WORK QUALITY OF GAS PUMPING STATIONS

Мezerya А. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-09

The article presents the results of the analysis of existing regulatory support for improving the quality of work of gas pumping stations and their elements, the main of which are compressor units. It is shown that in order to ensure high quality indicators of the work of gas pumping stations and their elements, there are a number of regulatory documents that consider the issues of operation, metrology, testing, energy saving and other important areas aimed at increasing and maintaining quality indicators that must meet international standards. The main indicators of the quality of work of gas pumping stations, which are divided into technical and economic, are given. The potential of increasing energy efficiency, which is one of the main technical indicators of the quality of work, has been determined. It is shown that the potential for increasing energy efficiency is the limiting value for increasing the efficiency of gas pumping station equipment. It was established that the possibility of realizing this indicator depends on the specific conditions of the gas pipeline system, as well as on the possibility of improving the technical condition of the gas turbine installation. The shortcomings of the existing regulatory framework have been identified, namely: there is a lack of regulatory methods for creating automated control systems that guarantee high quality indicators of gas pumping stations, first of all, the efficiency ratio, which can be increased by reducing all types of energy losses. Identified tasks regarding the further improvement of regulatory support of Ukraine: in-depth theoretical and experimental research, improvement of mathematical models of the main equipment of gas pumping stations and control systems; checking the adequacy of improved mathematical models according to experimental characteristics; implementation of structural and parametric synthesis of energy-efficient control systems. For the purpose of structuring regulatory documents and finding effective directions for improving the quality indicators of gas pumping stations, a classification of existing regulatory support was developed.

IMPROVING QUALIMETRIC APPROACHES TO RISK ASSESSMENT OF ENERGY COMPANIES TAKING INTO ACCOUNT CYBERSECURITY ASPECTS

Lysenko A. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-10

The article considers the possibility of applying qualimetric approaches to risk assessment, taking into account modern aspects of cyber threats arising in energy enterprises. For the purpose of risk assessment and management, the scientific, technical and regulatory framework was analysed and an algorithmic scheme was proposed that takes into account the cyber component, which is both a separate threat to the functioning of an energy enterprise and can influence other threats of various nature, and as a result increase the overall risk level. In the course of the study, a scientifically based methodology for assessing the level of enterprise security, taking into account cyber threats, was developed. The proposed approach combines qualimetric methods and a modified system of weighting coefficients, which made it possible to form an integrated risk analysis model that provides a more comprehensive view of the state of security of the and enables the timely detection of critical vulnerabilities both at the stage of planning security measures and during the adoption of management decisions in the course of operations. The study analysed the basic threats to a nuclear power plant, which made it possible to identify hidden threats, namely, it was established that the failure of cooling systems can be caused not only by physical malfunctions, but also by deliberate interference with software or distortion of sensor signals, which is taken into account when assessing risks. The paper presents a visualisation of risk assessment in the form of a 3D risk matrix with a cyber component, which provides a better understanding and helps energy company managers quickly identify the most critical risks in which the cyber factor significantly increases the threat. The application of the integrated model has shown that the actual level of risk at a nuclear power plant increases significantly due to the cyber component. Compared to the baseline assessment, the integrated risk indicator, taking into account the cyber component, increases by 10–25%, confirming the need for the systematic inclusion of cyber protection measures in the overall nuclear energy security policy.

IMPROVEMENT OF REGULATORY APPROACHES TO TECHNICAL DIAGNOSTICS OF NPP POWER EQUIPMENT

Ovcharov O. — 2025-12-30

DOI: https://doi.org/10.26565/2079-1747-2025-36-11

The article discusses the problem of improving regulatory approaches to technical diagnostics of power equipment at nuclear power plants, in particular the stator winding rods of TVV-1000 type turbogenerators. The relevance of the topic is due to the need to improve reliability and safety in conditions of beyond-design-basis operation of power units and the development of appropriate regulatory programmes for technical diagnostics. Based on a review of current international and domestic standards and an analysis of the latest methods of thermal and non-invasive diagnostics, the paper proposes a step-by-step regulatory programme for diagnosing cooling water consumption in the cooling system of turbogenerator stator cores, based on the use of an ultrasonic flow meter and thermal analysis algorithms. Criteria for assessing the technical condition of the bars are defined and appropriate corrective actions are proposed when deviations are detected during preventive maintenance work for power units of nuclear power plants. The results obtained can be integrated into PLiM turbine generator resource management systems.