Electrical Engineering Industry Research Articles

Information model for assessing the impact of tactical material procurement risks on order fulfillment in make-to-order manufacturing

Manufacturing businesses are showing increased interest in the issue of supply risks for materials and components. In recent decades, numerous studies and reviews have been published on the subject of supply chain risks. However, most research examines the global impact of risks on business as a whole and proposes a multi-level procedure for identifying, assessing, and developing risk mitigation measures, which should be carried out in advance with the involvement of specialists and experts. Nevertheless in maketo-order manufacturing, it is important to assess the risks of material supply for individual production orders, at the same time taking into account constant changes in production state and supply chains. The problem of assessing the risks of material supply gets even more complicated at enterprises with a high mix of manufactured products. To solve the above-mentioned problems, the authors propose an automated model for risks evaluation. The model is implemented as a component of the enterprise's information system (ERP) and uses data from the technological, production, inventory, and logistics modules to calculate the probability of deviation in order fulfillment time from the planned schedule due to potential disruptions in material supply chains. When executing the model, it analyzes the production's material requirements in both volumetric and calendar terms, inventory levels, and the condition of supply channels. The risks of delayed delivery for each material are expressed as the standard deviation of the delivery date from the planned date and are calculated by composing the risks for segments (elements) of the supply chain, the risks for which are, in turn, calculated based on performance data accumulated in the logistics module, with the possibility of introducing correction coefficients and expert evaluations. The overall risk of order material supply is determined by summing up the delivery risks of individual materials, expressed as the corresponding standard deviations. The model's results can be used for managerial decision-making in production and procurement or for communicating expected order fulfillment times to customers. The model has been tested at an enterprise in the electrical engineering industry.

Analysis of impulse withstand voltage of ester-based nanofluids

Ester-based nanofluids constitute an effective ecological alternative to petroleum-derived dielectric fluids for electrical engineering industry. Pulse induced dielectric breakdown is a key cause of power device failure. In this paper, we deal with the lightning impulse breakdown voltage (LI BDV) in natural and synthetic ester-based (NE and SE) nanofluids with various concentrations of magnetite (Fe3O4) and fullerene (C60) nanoparticles. The nanofluids show a decrement in positive polarity LI+ BDV as compared with the base ester. Negative polarity LI- BDV in the nanofluids is similar to that of base oils. Weibull statistical distributions are applied to analyse the results at different cumulative probabilities of 1 %, 10 %, and 50 %. Natural ester with C60 nanoparticles shows higher positive LI+ BDV values at a low probability level, while the negative LI- BDV reaches higher values at higher probability levels. The decreased LI BDV in NE and SE due to the magnetite nanoparticles are attributed to the nanoparticle clustering and percolation. The tendency of C60 nanoparticles to enhance the LI BDV in NE but not in SE is interpreted in the view of the nanoparticle concentration and oil's viscosity effect on the streamer branching and propagation.

Specific Features of the Development of Electrical Engineering Enterprises in the Conditions of Digitalization of the Economy

Article discusses the concept of digitalization, its role and importance in the development of the electrical engineering industry. The essence of the digital transformation process, the strategy of applying this process to the activities of enterprises and ways of implementing this strategy, including the introduction of modern information systems and software products improvement of the quality of products and services, trends in the development of electrical engineering products in the industry were discussed.

Влияние добавок Cu на микроструктуру и свойства сплавов системы Al–Fe, полученных методом литья в электромагнитный кристаллизатор

The modern electrical engineering industry requires cheap and easily reproducible aluminum alloys with advanced mechanical strength and electrical conductivity. This work studies the influence of small (up to 0.3 wt. %) copper additions on the microstructure and physical and mechanical properties, as well as phase transformations in the Al–Fe system alloys with an iron content of 0.5 and 1.7 wt. %, produced by continuous casting into electromagnetic crystallizer. Alloys of the above chemical compositions were produced, and subsequently annealed at 450 °C for 2 h. In all states, the microstructure (via SEM), yield strength, ultimate tensile strength, elongation to failure, and electrical conductivity were studied. It has been shown that copper additions lead to an increase in the strength of both alloys and a slight decrease in their ductility compared to similar materials without copper. An increase in strength and a decrease in ductility due to the copper addition is associated with the formation of more dispersed intermetallic particles in copper-containing Al–Fe system alloys. Additional spheroidizing annealing leads to a decrease in the length of the interphase boundary between the aluminum matrix and iron aluminide particles due to a change in their morphology, which leads to an increase in electrical conductivity. In general, copper-containing alloys showed higher mechanical strength with lower electrical conductivity, as well as higher thermal stability.

PRESSURE EFFECT ON POOL BOILING HEAT TRANSFER CHARACTERISTICS OF HIGH-VOLATILE LIQUIDS WITH STRUCTURED SURFACE

The study of enhancement of the heat transfer during boiling and an increase of the critical heat fluxes (CHF) have a great importance in design of the modern and cost-effective heat transfer devices for thermal management of microelectronics, cryogenics and refrigeration, and the power electrical engineering industry. In this work we present the results of the experimental studies of the heat transfer and CHF during the pool boiling of refrigerants R113, RC318, and dielectric liquid HFE-7100 on a structured surface under saturation conditions in the range of reduced pressures 0.03-0.36. The effect the heat flux and pressure on the boiling heat transfer coefficient was studied. It is shown that the correlation of Yagov predicts with an accuracy of ± 35% the CHF for pool boiling of highly volatile liquids on structured surfaces in a wide range of reduced pressure.

Fast Degradable and Thermally Conductive Silicone Rubber Vitrimer with Low Dielectric and UV‐Shielding Properties

AbstractSilicone rubbers are widely employed in various fields such as electronics, electrical engineering, mobile communications, aerospace, and automotive industries. However, silicone rubbers are typically challenging to reprocess and degrade. Moreover, with the advancement of technology, higher demands are placed on its thermal conductivity and dielectric properties. In this study, diglycidyl ether terminated polydimethylsiloxane is cured by 4,4′‐dithiodibutyric acid which contains dual dynamic covalent disulfide and ester bonds with triazobicyclodecene as the ester exchange catalyst to prepare silicone rubber vitrimers (SRVs) through a casting method. The SRVs demonstrate a relatively higher intrinsic thermal conductivity of 0.26 W (m⁻1 K⁻1) compared to ≈0.20 W (m⁻1 K⁻1) of conventional silicone rubber. Besides, the SRVs exhibit very low and stable dielectric constant and dielectric loss at both low and high frequencies (X‐band). The lowest dielectric constant and dielectric loss tangent at 10 GHz are 2.75 and 0.0650, respectively. Besides, the dual dynamic covalent bonds enable the SRVs to have excellent reprocessability and fast degradability. Moreover, the SRVs reveal UV‐shielding capability, as the transmittance of the SRVs is 0% from 200 to 400 nm of UV light.

THE ROLE OF THE COPPER CLUSTER IN THE INNOVATIVE DEVELOPMENT OF ELECTRICAL ENGINEERING ENTERPRISES

The rapid development of the global green economy, the increase in the production of renewable energy sources and electric cars are increasing the demand for the electrical engineering industry. In our country, in the conditions of modernization of the economy and transition to innovative production, deep quality changes are taking place in the branches of the electrical engineering industry. This article is devoted to the discussion of reforms, strategies and methods that should be implemented in this direction.

Analysis of industrial enterprises of the electrical engineering industry in St. Petersburg and Russia

Analysis of industrial enterprises of the electrical engineering industry in St. Petersburg and Russia

STUDY OF TRANSIENT RESISTANCE OF CONTACT MATERIALS AND CONTACTS OF ELECTRICAL DEVICES DURING INTERACTION WITH AGGRESSIVE ENVIRONMENT

It is proposed to replace serial contact parts based on silver with experimental contact units based on copper. Climatic tests of contact materials were carried out to determine the performance and production operation of experimental contacts. As a result of the change in contact resistance and mass of samples of copper-based contact materials with thermodynamically stable impurities and on the basis of petrographic analysis of their interaction products, transient resistance and corrosion resistance of electrical contact materials in chemically active environments were evaluated. Stable transient resistance and high corrosion resistance of the studied materials in NH3 and CO2+H2O environments are shown. To determine the operability of the starters, tests were carried out on the reliability of contact of the starters. These studies were carried out for serial contact parts of PML-1100O4 electromagnetic starters based on silver - СрН-90, СрМ-0.2+М1 and metal-ceramic contact parts based on copper with metal impurities and defined thermodynamically stable compounds. Contact units of the starters, made of experimental contact materials, have passed several years of production tests in real agricultural conditions. The reliability of the electrical contact is largely determined by the components that make up its composition, the structure and properties of the surface layers, which are formed as a result of erosion and transfer of the contact material in the electric arc.The main component for the contact materials of the most common electromagnetic starters is silver.Corrosion of the working surfaces of the contacts of the starters, which occurs under the influence of chemically active impurities in the environment, is also one of the main factors of wear and failure. Contacts of PML, PM, PMM, PME, PMA, PAE starters are made of silver-based material (СрН-90, СрМ-0.2+М1, СОК-15, КМК-А10м, etc.). Since the reliability of starters with developed test contacts involves the preservation over time of the parameters that characterize the ability of electromagnetic starters to perform their functions in all prescribed modes and in harsh operating conditions (environmental conditions of technological animal husbandry premises), the reliability indicators are controlled during all tests: when monitoring the functioning of the starter and when testing for the influence of external factors (control tests). In order to reduce the time and means of testing, one-stage control is used, in which one sample is tested (based on the results of the test, a decision is made about compliance with reliability requirements). As a rule, the technological equipment of livestock farms and complexes mainly includes electromagnetic starters of general industrial purpose of wear resistance class B, B. Such starters are unsuitable for long-term operation in specific conditions of agriculture, as they do not meet the requirements for protection against environmental influences, fail before reaching a certain resource of wear resistance, and this primarily concerns the contact system (up to 30% of all starter failures). Today's modern electrical engineering industry does not produce starters and relays for the needs of the agro-industrial sector. In order to improve the reliability of the contact system of the electromagnetic starter and relay in general, it is suggested to replace the serial contact parts with copper-based contact parts. The aim of the study -carrying outcomparative studies of the characteristics of electromagnetic starters with serial and experimental test contact parts and the identification of the influence of aggressive environment parameters on the nature of changes in the transient resistance of contact materials and contacts of starters.

The hybrid mathematical model for the evaluation and selection of iron ore raw materials in the context of the European Green Deal

The actual scientific research on the development of the hybrid mathematical model for evaluating and selecting iron ore raw materials in the context of the EU Green Deal is carried out. The necessity of developing decision support systems within the framework of the EU Green Deal concept is substantiated, in order to increase the degree of validity of decision-making in the evaluation space, regarding the green course and achieving the goals of the green agreement. For the first time, a systematic theoretical-multiple model of the problem of evaluation and selection of iron ore raw materials, according to the proposed factors of chemical composition, cost, and environmental policy of the manufacturer. The problem of multi-criteria selection of alternatives based on the imaginary alternative of the "satisfaction point" of the decision-makers (DM) requirements using the information model of criteria for evaluating the properties of the object of study on the chemical composition of iron ore raw materials. For the first time, a hybrid mathematical model of multi-criteria evaluation of iron ore raw materials with target needs was developed: quality of chemical composition of iron ore raw materials; the cost of iron ore; environmental policy and environmental impact in the extraction and/or enrichment of iron ore raw materials. The results of a study on a real example of evaluation and selection of iron ore concentrate for six alternatives implemented by Metinvest (Ukraine) were tested. The general step-by-step algorithm of the evaluation concept is described, which can be quickly implemented in the software product for the application. The developed model will be a useful tool for various programs of state support/business assistance in the procurement of iron ore raw materials by reasonably choosing a supplier using targeted needs in the context of synchronization with the EU Green Deal initiative. Raw material extraction and subsequent transport logistics are especially important for the engineering industry, the electrical engineering industry, and the automotive industry, with strong potential for the aeronautics and aerospace industry.

FEATURES OF TRANSLATING POLYSEMANTIC TERMS OF THE ELECTRICAL ENGINEERING AND POWER INDUSTRY

The main purpose of the article is to study the features of translation of polysemantic terms of the electrical and electrical industries, as well as to analyze the means of translation in connection with the improvement of the translation of technical texts. The article analyzes the technical terms of the electrical and electric power industries and identifies the difficulties that arise during their translation into Ukrainian. In particular, one-word and verbose terms are distinguished and their features can be traced when translated into Ukrainian. Polysemantic terms in technical texts, the translation of which causes the most difficulties, are also presented and analyzed. Based on the results of the analysis, a conclusion is made about the peculiarities of the translation of technical terms as a whole. Given that in the modern world there are more and more terms that are key in scientific and technical discourse, the issues of their functioning and translation are relevant and require constant and detailed study.
 Keywords: technical translation; terms of the electrical engineering and power industry; terminological system; polysemy of terminology; translation of terms.

Influence of Nanoclay on the Thermo-Mechanical Properties of Silicone Pressure-Sensitive Adhesives.

This research was carried on newly obtained innovative materials-self-adhesive one-sided tapes based on silicone pressure-sensitive adhesives. In order to obtain tapes, the stable adhesive composition was subjected to physical modification by incorporating into it various amounts of selected silicon fillers. The produced pressure-sensitive adhesives were tested for viscosity and thermogravimetric analysis, as well as the manufactured tapes; i.e., peel adhesion, tack, cohesion at room and elevated temperature, SAFT test (shear adhesive failure temperature), and shrinkage. The prepared self-adhesive tapes retained their self-adhesive properties at a level close to the initial level while increasing the thermal resistance by 70-75 °C, reaching the level of 220-225 °C. The new self-adhesive materials have application potential and can be used as a material for special applications in the field of electrical engineering and heavy industry.

RECURRENT USE OF A PERCEPTRON FOR SIGNAL STRUCTURAL ANALYSIS

The paper is devoted to the use of an artificial neural network (ANN) of direct propagation (multilayer perceptron) for signal processing in electrical engineering and electric power industry. It is proposed to use such simple neural networks instead of ANN with a more complex structure (convolutional, recurrent), but within the framework of a sequential recurrent algorithm. This allows checking and controlling the quality of signal processing at each stage of calculations. The proposed algorithm is tested on the example of structural analysis of a signal with nonlinear distortions in a sliding time window. It is shown that the amplitude, frequency and phase of an industrial frequency signal with a high level of harmonics and an aperiodic component can be isolated with an accuracy of units of percent for a time not exceeding units of milliseconds. To increase the accuracy at each step of the calculations, traditional methods can be used, in addition to the ANN: averaging, median smoothing, etc.

Female Engineering Students’ Motivations, Career Decisions, and Decision-Making Processes: A Social Cognitive Career and Motivation Theory

Although women’s rights and career developments have changed over the past decade, only a few updated studies have been conducted to understand the current backgrounds of women in engineering. This study aims to understand and investigate the motivations, career decisions, and decision-making processes of a group of women in the engineering industry, specifically, a group of electrical and electronic engineering students in Taiwan. Based on social cognitive career and motivation theory, the study was guided by two research questions: 1) Why do Taiwanese female electrical and electronic engineering students decide to study this major at university level? 2) Do the participants intend to join the electrical and electronic engineering industry after graduation? Why or why not? The general inductive approach research design with interview, focus group, and member checking interview were used. The results indicated that academic interests, interests in career development, and job security concerns played significant roles in the motivations, career decisions, and decision-making processes of a group of female engineering students in Taiwan. The results of this study filled the gaps in gender discrimination, social stigma, and stereotype toward women in engineering, particularly in Taiwan.

FEATURES OF THE CALCULATION OF THE USED PLASTICITY RESOURCE DURING COLD FORMING OF GLASS-TYPE PRODUCTS

The reverse extrusion process is widely used in the production of “Glass” type parts. Due to high technical and economic indicators and great technological possibilities, in recent years, cold plastic deformation has become widely used in machine- and instrument-building plants, in the electrical and radio engineering industry, as well as in other branches of the national economy. However, the possibility of cold plastic deformation by the extrusion method is not yet sufficiently used. The reason is that, traditionally, during the design of metal pressure processing processes, attention is paid to determining the power parameters and ensuring the geometric accuracy of the workpieces. But this does not allow us to assess the ultimate shape change and technological heredity of the finished products and make a quantitative assessment of the damage of the deformed metal. In this work, the process of forming products of the “Glass” type by reverse cold plastic deformation is investigated, in which the used plasticity resource is taken as the most important parameter responsible for the quality of the products. The method of calculation of the used resource of plasticity of “Glass” blanks in the processes of reverse cold plastic forming is clarified. When calculating the used plasticity resource, the effect of the volume of the stress state scheme is taken into account by using the limit deformation surface instead of the plasticity diagrams. The graphs of distribution of the resource of plasticity by the radius of the workpiece are obtained. From the analysis of the results it follows that the greatest intensity of accumulation of damage occurs in the areas of maximum irregularity of plastic deformation. Points of contact of the punch with the workpiece turned out to be dangerous. The use of hydrostatic support in reverse extraction allowed not only to reduce the degree of plasticity used, but also to obtain a more uniform distribution of it, therefore, to improve the quality of the obtained blanks when reverse extrusion and improve the technological heredity of the finished products. The results obtained in the work can be used to estimate the limit change in shape in similar technological processes, which are accompanied by a volumetric scheme of the stressed state.

Cutting force and vibration prediction of milling processes regarding the nonlinear behavior of cascade controlled feed drives

Milling processes are characterized by their high degree of flexibility regarding shape creation and thus occur in many value adding processes in the electrical and mechanical engineering industry. To facilitate the systematic prediction and the efficient optimization of the process performance, a holistic simulation model of the milling process with cascade controlled feed drives is developed. The integrated model consists of two subsystems, namely the feed drive model and the process model. In the feed drive model, the dynamic models of the electric motors, the serially connected torsional oscillators of the mechanical elements and the cascade control system are established. In this model, the coordinate point of the milling tool is computed at each discrete time step and assigned to the process model. The cutting forces and the corresponding load torques are calculated in the process model and sent back to the feed drive model. In addition, practical validation of the complete system has been conducted both in the time and the frequency domain. The simulation results yield an accurate prediction of the tooth passing frequency with a variance of less than 1%. Moreover, the influence of the cascade control parameters and the nonlinear behavior of the electric motor on the process vibrations have been experimentally verified.

Some peculiarities of obtaining composite materials, based on alicyclic (co)polyimide and polyethylene glycol (Review)

The current trend in obtaining new structural polymeric materials for mechanical engineering, agriculture, food industry, instrumentation, electrical engineering, electronics, and other industries is the development and use of mixed compositions based on structural thermoplastics. A special place among the initial components for the creation of structural materials is occupied by heat-resistant polymers, in particular polyimides. Сurrently, lots of thermoplastic and thermosetting polyimides and other imide-containing film-forming polymers have been synthesized and successfully processed into composite materials with special properties.The goal of this research was to consider the features of obtaining binary and ternary polymer mixtures based on alicyclic (co)polyimides containing polyethylene glycol with other polymeric additives and the mineral montmorillonite. Based on the IR spectroscopy data of compositions and films, the effect of the surfactant polyethylene glycol on the compatibility of components in the composition and the possible mechanism of interactions of polyfunctional polymers as well as alkylated montmorillonite is shown. The formation peculiarities of ternary compositions (co)polyimide + polyethylene glycol + an additional component (polyacrylamide, polyethyleneterephthalate, alkylated montmorillonite) is provided. The thermal and physical-mechanical properties of the films formed from composites, determined by the appropriate methods of thermogravimetric analysis and stretching of the material at a constant strain rate are presented. It was established that the best indicators of the studied properties are polyimide (copolyimide) + polyethylene glycol + alkylated montmorillonite composite films where the decomposition start temperature is 430 ºС, the breaking strength is 200 MPa, and the relative extension is about 24%.

ANALYSIS, PRACTICAL APPLICATION AND POSSIBLE INTERCONNECTION OF INDUSTRIAL ENGINEERING METHODS AND KEY PERFORMANCE INDICATORS

In connection with applying the principles of Industry 4.0, the industrial practice also requires the consistent application of industrial engineering methods to improve process performance. The transformation of society into digital affects almost all areas of industry, public administration, healthcare and all walks of life. The implementation of Industry 4.0 is very important in the automotive, engineering and electrical engineering industries. It is the move towards Industry 4.0, the collection of large amounts of data and the decision-making based on the data obtained that provide the ideal basis for using more complex industrial engineering methods and better process evaluation. The paper's main goal is to analyse and identify the use of industrial engineering methods and key performance indicators of companies in industrial practice in Slovakia, where practice shows a lower acquaintance with these methods, especially among medium-sized companies. The paper deals with the issue of industrial engineering methods aimed at improving process performance in the context of key performance indicators. The paper contains some results of a questionnaire survey aimed at gathering information on improvement methods and identifying the use of key performance indicators in industrial practice. Which results will bring us closer to which types of methods are most used in Slovak practice and why?

Влияние старения на микротвердость и электропроводность сплава Cu–2 вес. % Be

Goods made of beryllium bronzes got widespread use in the industry due to the complex of properties: high heat conductivity, strength, hardness, wear resistance, and corrosion resistance. They are not magnesium-based and do not spark on impact; therefore, they are essential for the production of non-sparking tools. The alloys of this system are used in the electrical engineering industry; consequently, it is necessary to pay attention to the improvement of the material’s electrical conductivity. The paper studies the microstructure, microhardness, and electrical conductivity of the Cu–2 wt.% Be alloy exposed to high-pressure torsion (HPT). The authors investigated the microstructure and fine structure of the alloy in various states. The study showed that HPT leads to the formation of an ultrafine-grained nanostructured (UFG NS) state with an average size of grains/subgrains of 22±1 mmn. Additional ageing of samples after HPD led to a slight increase in the grains/subgrains size up to 31±1 mmn. In both states, the authors observed nanosized deformation twins. The authors studied the dependences of microhardness and electrical conductivity of the alloy after HPD on the time of further ageing. The study identified that the microhardness increases from 122±3 HV in the initial state up to 525±8 HV after HPD and ageing. The investigation shows that the electrical conductivity substantially better recovers after ageing of the UFG NS state compared to the initial state. The electrical conductivity of the UFG NS state increased from 14.5±0.1 % IACS up to 27.5±0.6 % IACS in conditions similar to the initial state ageing. Therefore, resulting from such processing, the Cu–2 wt.% Be alloy is characterized by its advanced strength properties and electrical conductivity.

Glass Fibre Reinforced Epoxy Composites Modified with Graphene Nanofillers: Electrical Characterization

Composites with improved electrical properties created new pathways in electrical engineering industries. In this work, electrical studies conducted on continuous unidirectional E‐glass fibre‐reinforced epoxy composites modified with three different graphite oxide fillers are discussed. The three different fillers are (i) graphite oxide (GO), (ii) exfoliated graphite oxide (EGO), and (iii) reduced exfoliated graphite oxide (rEGO). Incorporation of GO fillers exhibited significant improvement in the dielectric characteristics of the composites, where it showed 42% enhancement in breakdown strength values. Dielectric constant measurements of GO‐filled composites have also demonstrated considerable enhancement in the values where the fillers promoted interfacial and dipolar polarization phenomena in the material. On the other hand, in the case of EGO and rEGO fillers, conducting nature induced from graphitic structure had significantly reduced the dielectric properties of their composites.