Yu. P. Makushev, T. A. Polyakova, L. Yu. Volkova, V. V. Ryndin
Kinematic calculation of eccentric mechanisms using the Mathcad software 
DOI: 10.25206/1813-8225-2025-193-13-20
The article determines the value of the pusher stroke of the eccentric mechanism with the 4 to 6 mm eccentricity basing on graphic research. By approximating the graphs of the pusher stroke on the eccentric surface, the authors propose a calculation formula, which defines the pusher stroke as a function of the angle of the eccentric shaft rotation for practical purposes. Moreover, formulae for determining the velocity and acceleration of the eccentric mechanism pusher are offered. The relative error does not exceed 6 % in determining the pusher stroke by graphical and calculation methods. Calculations and graphs of path, velocity, acceleration of the eccentric mechanism pusher with eccentricity of 4, 5 and 6 mm at a shaft speed of 1000 min-1 are calculated and plotted using Mathcad software. The practical implementation of eccentric mechanisms for power supply systems of internal combustion engines is considered.

Keywords: eccentric, eccentricity, Mathcad, pusher stroke, pusher velocity, pusher acceleration, implementation of eccentric mechanisms.

V. A. Tretyakova, S. S. Voronin
Development of stages for assessing labor intensity of research and development in manufacturing enterprises
DOI: 10.25206/1813-8225-2025-193-21-29
To produce competitive products, enterprises must engage in research and development activities. This work involves numerous specific factors that significantly complicate the process of labor intensity assessment. Existing labor standardization methods, while potentially applicable for evaluating labor intensity, are not fully adapted for research and development activities. Therefore, it is advisable to develop dedicated stages for assessing the labor intensity of research and development activities, allowing for consideration of all unique factors relevant to these activities.

Keywords: research and development, research work, development work, labor intensity, planning, standards.

A. V. Shimokhin, A. N. Sorokin, S. N. Boltovsky, V. N. Kuznetsova, I. S. Kuznetsov
Investigation of the strength property of 3D printed products in bending deformation to optimize material distribution
DOI: 10.25206/1813-8225-2025-193-30-37
The article considers a method of optimal material distribution inside a 3D printed sample. Several variants of material distribution are considered, including the beam shape of equal resistance while retaining the outer frame of the specimen as a rectangular parallelepiped with a square cross-section. The manufactured samples are subjected to destruction during static bending testing. The results show the reduction of used material by 30 % and preservation of specimen strength properties with 100 % material filling. Moreover, experimental results are presented and research issues for further investigations are highlighted.

Keywords: additive technologies, equal resistance beam, topology optimization, 3D printing, static bending test, mechanical properties, weight reduction.

N. V. Bobkov, A. A. Fedorov, S. V. Petrochenko, N. S. Artemenko, R. V. Chulkov
Search for optimal parameters of wire electrical discharge machining of parts made from E110 zirconium alloy  

V. V. Sushkov, V. N. Goryunov, E. E. Revyakin
Advancing efficiency of a drilling rig electrical system with a battery energy storage system
DOI: 10.25206/1813-8225-2025-193-50-57
The article considers an inner current control loop design for a grid inverter of the battery energy storage system. For this purpose, a well-known methodology of subordinate control system design is used. According to this methodology the controller coefficients can be determined based on analytical findings. This approach will help prevent indefiniteness during the practical implementation of the automatic control system of grid inverter. The aim of the work is to advancing efficiency of the electrical system of a drilling rig with a battery energy storage system under peak load conditions.The problem of analytical determination of the coefficients of regulators in the automatic control system of a grid inverter has been solved. The structure of the automatic regulation system has been proposed. The efficiency of the automatic control system for the grid inverter is verified by the numerical indicators of the transient process quality obtained.in this article. 

Keywords: drilling rig, grid inverter, energy storage system, automatic control system, subordinate regulation system, peak load.

I. V. Yaroshenko, V. V. Nosenko, M. S. Altunina, Yu. P. Aksenov
Experience in determining technical condition and evaluating the lifetime of transformers based on the results of a comprehensive diagnostic examination 
DOI: 10.25206/1813-8225-2025-193-58-67
The article considers a comprehensive approach to assessing the residual lifetime for transformers with a significant service of more than 30 years. Using the example of a comprehensive diagnostic examination of two transformers, it is demonstrated that transformers have different options for aging the active part and the approach to resource assessment should be different. The first option is a uniform general «aging» of the active part, the fact of aging affects reliability after 50–60 years. The second option is the occurrence of a local defective node with vibration (VIBRO) and electric discharge phenomena (ERA), the defect appears spontaneously after 15–25 years. The appearance of critical defects can be recorded on-line using innovative techniques. The processes that determine the aging of the nodes of the active part are the phenomena of «VIBRO»–«ERA»–«THERMO»–«HARG». By analyzing the parameters and dynamics of phenomena, it is possible to assess the technical condition and resource. This approach is confirmed by the analysis of the technical condition of typical variants of defects in transformers.

Keywords: electric discharge phenomena, vibration phenomena, vibration shocks, degree of compression, measure of destruction, thermal imaging control, HARG.

A. I. Golodnova, M. V. Erpalov, A. I. Golodnov
The use of mathematical model to evaluate the material balance of a solid oxide electrolyser
DOI: 10.25206/1813-8225-2025-193-68-75
The effective use of solid oxide electrolysers is a promising solution for the energy sector and industry in general. Therefore, scientists all over the world are conducting research on improving the electrolysers' efficiency and reliability. In this paper, a mathematical model of the material balance for a solid oxide electrolyser is considered, which allows optimizing the operating parameters of existing equipment and newly designed equipment. In particular, special attention is focused on studying the effect of the operating parameters of electrochemical plants of planar design during electrolysis on the composition of reaction products. The relation between the compositions of reagents at the inlet and products at the outlet is determined on the basis of calculated data for a planar solid oxide electrolyser using mathematical modeling in comparison with experimental data.

Keywords: mathematical modeling, electrochemical devices, solid oxide electrolyser, chemical reactions, material balance, current strength, voltage.

A. V. Petukhov
Development and research of the control system of the group variable frequency drive with increased resistance to network voltage sags 
DOI: 10.25206/1813-8225-2025-193-76-83
The functional scheme of the frequency converter control system is presented, that allows limiting the current surges at the input of the autonomous voltage inverter at the moment of sharp voltage recovery in the supply network. The author describes the research results of the proposed control method in the simulation modeling of a frequency-controlled drive in the MatLab software.

Keywords: power supply system, minimum voltage protection, frequency converter, control system, voltage inverter, common rectifier, voltage dip, frequency regulation, DC link.

A. S. Makarov, V. V. Kharlamov, D. I. Popov
Methodology development for estimating the residual resource of diesel locomotive traction generator brushes
DOI: 10.25206/1813-8225-2025-193-84-90
The article presents the formation of a mathematical model of the wear process and estimation of the residual resource of synchronous traction generator brushes. The authors propose to consider the peculiarities of operation and technical condition of the brush assembly in calculating the residual resource of electric brushes. The data arrays collected by the on-board monitoring system are analysed and required parameters for determining the residual resource of electric brushes are identified. The article provides a mathematical model of wear intensity of the traction generator electric brushes. The authors present the experimental research plan for determining the mathematical model coefficients. There is a scheme of experimental installation for determining the residual resource of synchronous generator brushes. The authors obtain dependences of the residual resource value on the change of operating modes.

Keywords: wear, methodology, mathematical model, electric brush, brush assembly, residual resource, full-factor experiment.

A. K. Toropova, V. V. Cherepanov
Calculation of the mode of higher harmonics in electrical networks of plywood production
DOI: 10.25206/1813-8225-2025-193-91-97
The trouble-free operation of the power supply system elements of plywood production largely depends on maintaining the required quality of electric energy. It is essential to focus on calculation of higher harmonics mode at engineering the power supply system of plywood production, as the process uses powerful semiconductor controlled rectifiers. The article discusses the controlled rectifier that is required for the operation of a four-foot veneer peeling machine. The authors determine that the presented unit generates higher harmonic currents into the network. These currents negatively affect all elements of the power supply system. However, there is no calculation method for the mode of higher harmonics in the power supply system of plywood production. Therefore, the purpose of the research is to develop a methodology for calculating the mode of higher harmonics in electrical networks of plywood production. The experiment was conducted at an operating plywood production in the Kirov region to achieve the research purpose. The investigation object was a four-foot veneer peeling machine. It was found that the higher harmonics generated by the main drive of the veneer peeling machine change randomly. The authors proposed to consider them as random variables in the calculations. The research determined statistical laws of the higher harmonics distribution and their numerical features. The authors obtained analytical expressions for calculating the amplitudes of the higher harmonics through the amplitudes of the main harmonic component of the current in the absence of information about the control and switching angles of the rectifier. The proposed technique allows calculating amplitude spectra of higher harmonic currents in branches and voltages in nodes of the power supply system of plywood production. According to the proposed methodology, the results of calculations are recommended for solving series of practical problems.

Keywords: electric power quality, electrical networks of plywood production, controlled rectifier, veneer peeling machine, higher harmonics, non-sinusoidal voltage, mode of higher harmonics, calculation method.

S. V. Biryukov
Two-component spherical dual-type electric field strength sensor 
DOI: 10.25206/1813-8225-2025-193-98-106
Simple and easy-to-use modern sensors are required to monitor the levels of electric field strength around high-voltage power equipment, power lines, substations. These sensors ensure safety and labour protection of power equipment maintenance personnel. Therefore, the development of electric field strength sensors is an important and urgent task. The article proposes one of the possible options for constructing such sensors. The sensor is a two-component spherical dual-type element. Twelve biangular spherical conductive electrodes are placed in isolation on the spherical conductive surface of the sensor. The electrodes serve to form the sensitive elements of four dual sensors: two on each coordinate axis. Moreover, the dimensions of the sensor sensitive elements affect its error caused by the inhomogeneity of the field. The dual spherical sensor has a variable error: not exceeding ± 1,1 % in the 0  a  1 entire spatial range, which corresponds to the d = R minimum distance to the field source. The error of the sensor is provided by reasonably selected angular dimensions of twelve bi-angular spherical electrodes of the 0 = 90 º and 01 = 30 º sensor basic. The sensor has three outputs on each coordinate axis, two corresponding to single sensors and one to a dual sensor. This type allows expanding the sensor's functional features. The dual spherical sensor is used for control and measurement means of electric field parameters of industrial frequency in high-intensity zones. 

Keywords: electric field, field strength, dual spherical sensor, double spherical sensor, sensitive element, spherical biconvex, field inhomogeneity error.