Electrical Engineering Applications Research Articles

Computational multiscale modelling of material interfaces in electrical conductors

Material interfaces occur at various length scales and may exhibit significantly different properties than the surrounding bulk. Motivated by their importance for electrical engineering applications such as wire bonds and electrically conductive adhesives, the focus of the present work is on material interfaces in electrical conductors. In order to approximate the physical interphase (of finite thickness) as a (zero-thickness) cohesive zone-type interface in macroscale simulations, scale-bridging relations are established that relate the apparent electro-mechanical interface properties to the underlying microstructure. A finite element-based implementation is discussed with particular focus lying on the efficient calculation of the flux-type macroscale quantities and the associated generalised algorithmic consistent tangent stiffness tensors. Analytical solutions are derived for validation purposes and representative boundary value problems are studied.

A practical algorithm for the design of multiple-sized porous scaffolds with triply periodic structures

In this study, we present a practical volume-merging method for generating multiple-sized porous structures that exhibit geometries with triply periodic minimal surface (TPMS) lattice structures. The proposed method consists of three stages: (1) designing the physical models with a signed distance field, (2) performing a merging operation for the porous scaffolds, and (3) assembling different units into a composite structure. The significant advantages of the proposed algorithm can be summarized as follows: Our method is independent of the model shape; the designed structures maintain a smooth surface with a constant mean curvature, and the mathematical computational complexity is low. We can join two different-sized triply periodic minimal surface lattices in the radial direction, where the transition region is obtained by smooth interpolation between the two lattice structures with different cell sizes or types. However, constructing large-sized models is only conceptually possible due to computational cost and memory storage constraints. To overcome these limitations, we present a practical method that can efficiently assemble large-scaled models at a low computational cost. The proposed method is based on a Boolean union operation of basic units of TPMS. Thus, it is simple to generate large-scale three-dimensional multiple-sized porous volumes based on our proposed method, which can be applied to many applications in mechanical and electrical engineering. The produced multi-scale compound scaffolds have smooth surfaces without fractures, making them suitable for straightforward application in additive manufacturing. Several numerical tests are conducted to validate the efficiency of the proposed algorithm.

Conformable Triple Sumudu Transform with Applications

One of the important topics in applied mathematics is the topic of integral transformations, due to their importance in electrical engineering applications, including communications in particular, and other sciences. In this work, one of the most important transformations in its three dimensions was presented, which is the triple Sumudu transform, including solving some real-life applications of physics, some of which have not been solved using such an integral transform before. In this work, we extend the Sumudu transform formula to the conformable fractional order, as well as other interesting and significant rules. The general analytical solution of a singular and nonlinear conformable fractional differential equation based on the conformable fractional Sumudu transform is also presented in this paper. The general solutions of several linear and nonhomogeneous conformable fractional differential equations can be obtained using the method we’ve proposed. As a result, our results reveal that our proposed method is an efficient one that can be used for solving all conformable fractional differential equations. The relationship between the Sumudu integral transform and other important and recently proposed integral transforms are also discussed. Finally, the triple Sumudu transform is used to solve boundary value problems, such as the heat equation with boundary values. The triple Sumudu integral transform is also used to solve linear partial integro-differential equations. The transform capability to handle such equations has been proven via its utilization in three applications.

An overview on Finite Different Method (FDM) in multilayer thermal diffusion problem

Numerous mathematical models have been developed for thermal diffusion through single-layer materials, while further developments are needed for multi-layer materials. Diffusion processes through a multilayer material are of interest in industrial, applied thermodynamics, physics, electrical and civil engineering applications. The proposed scheme is easily applicable in various fields, demonstrating that Finite Different Methods (FDMs) are flexible, simple to implement and help to represent multilayer materials even without associating them with other numerical methods. The numerical method studied is a FDM in a civil engineering application. Through the study of a multilayer wall, its criticalities are highlighted, and a possible implementation is proposed.

Comparison of physical properties of ferrofluids based on mineral transformer oil and bio-degradable gas-to-liquid oil

Ferrofluids based on mineral transformer oil have been intensively studied over two decades owing to their outstanding thermal and electrical insulating properties. However, current environmental demands on transformer operation give priority to the use of biodegradable transformer oils. Clearly, the differences in physical properties of biodegradable oils and those refined from crude oil determine the physical properties of ferrofluids based on the two types of oils. In this study, ferrofluids with various concentrations of iron oxide nanoparticles have been prepared on mineral transformer oil (M−oil) and biodegradable transformer oil based on gas-to-liquid technology (S-oil). The ferrofluids were subjected to experimental investigation of magnetization, AC magnetic susceptibility, thermal conductivity, viscosity and dielectric response. Based on zero-field-cooled and field-cooled magnetization curves, a lower temperature of a specific magnetization maximum associated with the melting of the oil (phase transition) was found for M−samples than for S-samples. The effect of carrier liquid on the onset of extrinsic superparamagnetism in addition to the intrinsic superparamagnetism is observed. Spectra of AC magnetic susceptibility of both types of ferrofluids exhibit quasi constant behaviour with amoderate decrease at high frequencies of amagnetic field. The viscosity of M−samples is slightly higher than that of S-samples. On the other hand, M−samples exhibit lower thermal conductivity than S-samples. In both cases, the thermal conductivity linearly decreases with temperature. Dielectric spectroscopy has revealed remarkable dielectric dispersion below 100 Hz in both ferrofluid types. The relaxation has been ascribed to interfacial polarization, which can be considered as a serious drawback from an electrical engineering application point of view. The measured physical properties of the ferrofluids are analyzed in regard to the density and viscosity of the base oils.

3D Printed All-Natural Hydrogels: Flame-Retardant Materials Toward Attaining Green Sustainability.

Biomass-based hydrogel is a promising flame-retardant material and has a high potential for applications in transportation, aerospace, building and electrical engineering, and electronics. However, rapid vat photopolymerization (VP) 3D printing of biomass-based hydrogels, especially that of all-natural ones, is still rare. Herein, a new class of VP 3D-printed hydrogels with strong covalent networks, fabricating using fully biomass materials and a commercial liquid crystal display (LCD) printer assembled with low-intensity visible light is presented. Encouragingly, the highly ordered layer-by-layer packing structures provided by VP 3D printing technology endow these hydrogels with remarkable flame retardancy, exceptional temperature resistance, advantageous combustion behaviors, and favorable mechanical strength, in particular, giving them a better limit oxygen index (83.5%) than various biomass-based hydrogels. The proposed approach enables the green design as well as the precise and efficient preparation for flame-retardant materials, paving the way for the future flame-retardant materials toward attaining green sustainability.

Carbon nanotubes/aluminum interface structure and its effects on the strength and electrical conductivity of aluminum

The contradiction between strength and electrical conductivity of pure aluminum (Al) hinders its wide applications in electrical engineering. In this study, an attempt was made to overcome this limitation by adding carbon nanotubes (CNTs) into Al matrix using friction stir processing (FSP) method. The results showed that CNTs were singly distributed in Al matrix and strong bonded CNTs/Al interfaces without chemical reaction as well as impurity contamination were formed. Interestingly, it was found that the axis of CNTs tended to be parallel to Al (111) planes, which provided a geometric basis for the formation of semi-coherent CNTs/Al interfaces. These semi-coherent CNTs/Al interfaces possessed an extremely low electrical resistivity, which weakened the total electron scattering generated by all CNT/Al interfaces. Meanwhile, strong bonded CNTs/Al interfaces effectively hindered dislocations movement, inducing an improvement of 84 % and 50 % in yield strength and tensile strength of Al respectively. As a result, the strength of Al was significantly improved without losing its electrical conductivity. This study provides a new strategy for breaking through the contradiction between strength and electrical conductivity of Al and then producing CNTs/Al nanocomposites with high strength and high electrical conductivity.

Physics-Informed Neural Networks for Solving 2-D Magnetostatic Fields

Physics-informed neural network (PINN) has shown great potential in the inverse and parametric designing problems in electrical engineering. Moreover, most existing works on PINN are dedicated to computational fluids, and very few attentions have been paid to static and low-frequency electromagnetic near fields with multiple media in electrical engineering applications. In this work, a PINN for solving two-dimensional (2D) magnetostatic fields in electromagnetic devices and systems is proposed. The magnetic field intensity and the magnetic vector potential are solved by training a neural network which encodes partial differential equations and boundary conditions as residuals. The computation of the spatial derivatives of media constitutive parameters, which negatively impacts the training of PINN, is eliminated. A mesh-assisted non-uniform sampling method for the selection of collocation points is proposed to further improve the performance of PINN. The proposed PINN is verified by comparing its results with those of the finite element method in two 2D magnetostatic case studies. It is expected that this work will promote further applications of PINN in the modelling, numerical analysis, and parametric design of electromagnetic devices and systems.

A Reconfigurable 4th Order IIR Filter For The Low Frequency Applications

Huge numbers of advanced electrical engineering applications employ infinite impulse response (IIR) filters very frequently in order to meet market’s demands. Especially, some applications such as video processing, digital signal processing and high-speed digital communication necessitate computational efficiency and low latency. In this point of view, high-speed processing of digital data require a digital signal processor or an FPGA instead of a conventional microprocessor. In this respect, in the last decades, FPGAs are commonly used in order to bring new opportunities to the designers. This work gives a FPGA hardware design of a 4th order IIR reconfigurable filter structure. The proposed filter’s maximum clock frequency is around 32MHz which covers different low frequency applications from biomedical signal processing up to speech applications. To verify the performance of the filter, 4th order Butterworth and Chebyshev filters are realized in the basis of Matlab results and FPGA behavioral model. Also, consuming logic gates and blocks are given in order to evaluate chip area occupation. It should be considered that the proposed filter scheme presents promising results to meet low frequency applications.

Mechanical Analysis and Constitutive Modeling of Nonlinear Behavior of Silver-based Conductive Ink

Stretchable electronic devices are progressively deployed in many applications of mechanical, electrical, and bio-medical engineering. These circuits are made of stretchable and flexible substrate, as well as conductive ink, and various electronic components. The choice of components and layouts for the substrate and conductive ink can regulate the stretchability of stretchable circuits. On top of that, the substance utilized to create the conductive ink must have high electrical conductivity and strong adherence to the substrate in order to produce a high-quality stretchable printed circuit. Thus, this study focused on the development of stretchable conductive ink using silver powder as a conductive filler and PDMS-OH as a binder. The mechanical properties of the synthesized ink were investigated via simple uniaxial tensile testing method and nanoindentation technique, respectively. Accordingly, the modulus of elasticity, tensile stress and yield stress of the ink were obtained as 5.72 MPa, 1.195 MPa, and 0.86 MPa, congruently at 137% strain before undergoing failure. The experimental stress-strain data was then employed on the elastic-plastic constitutive model to investigate the elastomeric properties of the ink as it is an alternative method of lengthy and expensive procedures of validating different polymers. Moreover, the hardness and reduced modulus of the ink were evaluated by nanoindentation method using 5 mN maximum load with 0.5 mN/s loading/unloading rate and 2 secs holding time. Consequently, the hardness and reduced modulus values were obtained as 1.45 MPa and 34.53 MPa, respectively. These values were further validated by Oliver-Pharr method, and were in a good agreement.

Controllable synthesis of composite electrode material to enhance the electrochemical performance of supercapacitors

Cobalt oxide (Co3O4), cobalt oxide/reduced graphene oxide (Co3O4/rGO), and cobalt oxide/reduced graphene oxide/polyaniline (Co3O4/rGO/PANI) ternary composites with varying PANI concentrations are created using the hydrothermal route and in-situ polymerization of aniline monomer. X-ray diffractometer XRD results reveal the presence of cubic Co3O4, hexagonal rGO, and emeraldine salt structure of PANI. SEM images reveal dense interconnected PANI fibers and rGO clusters across the quasi-cube-like Co3O4 structure. (Co3O4/rGO)/PANI (80%:20%) composites offer excellent optoelectronic properties with 2.32 eV bandgap. As the concentration of PANI increases, the (Co3O4/rGO)/PANI (40%:60%) exhibits 1673 dielectric constant, making it suitable for various electronics and electrical engineering applications. The electrochemical findings show that the (Co3O4/rGO)/PANI (60%:40%) based electrode has an exceptional capacitance of 3103.27 F/g at 2 A/g, maintaining a capacitance of nearly 92% after 10,000 continuous cycles. The composite also exhibits an extraordinary specific capacitance of 2101.3 F/g at 5 mV/s and the lowest ohmic resistance. These findings support the use of the (Co3O4/rGO)/PANI (60%:40%) ternary composite as a valuable and innovative electrode for supercapacitors.

Investigations on Dielectric Constant of Coir Powder-Reinforced PVC Composites

ABSTRACT In recent times, there is an intensive growth toward investigation and creation of the green fiber composites due to its abundance and cost-effective, renewable, and environmentally-safe features. Natural fiber-based composites are rapidly replacing synthetic fiber-based composites in electrical engineering applications but being limited due to poor electrical insulation properties. Hence, an attempt is made in this study to improve the electrical insulation properties of coir fiber (powder form)/polyvinylchloride composite by optimizing the variables viz. fiber content (wt.%), particle size (in μm), and chemical treatments using Box–Behnken design. Thus, the results are optimized using the analysis of variance to achieve the low dielectric constant (2.256) for the combination of chemical treatments (triethoxy(ethyl)silane), fiber content (2 wt.%), and particle size (179.5 μm), which are suitable for the electrical insulation products. Additionally, a conformity test is executed and error was found to be 2.54%.

The Application of Electrical Engineering and Automation Technology in Intelligent Buildings

Due to the economic development of the country, the building materials industry is also quietly emerging, and electrical engineering and its automation science and technology are widely used. Due to the improvement of people's life, the demand for architectural design and electrical is getting higher and higher, therefore, the correct use of electrical engineering and its automation science and technology is crucial to meet people's demand for architectural design, which not only can effectively use national resources, but also can greatly improve the efficiency of using construction projects and make positive contributions to social development. In order to ensure safety, we have to further improve the degree of application of electrical and intelligent technology. This will make the intelligent architectural design truly possible and effectively realize the intelligent function of architectural design. Therefore, this chapter will mainly discuss the importance and use of electrical and intelligent technology in the intelligent architectural design.

Application on Intelligent Technology of Electrical Engineering and Automation

In the electrical industry, the complexity and construction scale of electrical engineering are increasing, the traditional technology has been difficult to efficiently adapt to the development needs of the new era industry, deepening the popularization of the application of intelligent technology in electrical engineering and automation, is an important development direction of the electrical industry. This paper describes the basic connotation of electrical engineering and automation and intelligent technology, analyzes the electrical engineering and automation intelligent technology application in improving the level of system control, improve data processing accuracy and optimize the significance of system design, studied the electrical engineering and automation system in fault response processing, automation control, system design, the specific application of real-time monitoring.

An alternative simulation approach for surface flashover in a vacuum using a 1D2V continuum and kinetic model

Surface flashover across an insulator in a vacuum is a destructive plasma discharge which undermines the behaviors of a range of applications in electrical engineering, particle physics and space engineering, etc. This phenomenon is widely modeled by the particle-in-cell (PIC) simulation, here the continuum and kinetic simulation method is first proposed and implemented as an alternative solution for flashover modeling, aiming for the prevention of unfavorable particle noises in PIC models. A one dimension in space, two dimensions in velocity kinetic simulation model is constructed. Modeling setup, physical assumptions, and simulation algorithm are presented in detail, and a comparison with the well-known secondary electron (SE) emission avalanche analytical expression and existing PIC simulation are made. The obtained kinetic simulation results are consistent with the analytical prediction, and feature noise-free data of surface charge density as well as fluxes of primary and SEs. Discrepancies between the two simulation models and analytical predictions are explained. The code is convenient for updating and to include additional physical processes. The possible implementations of outgassing and plasma species for the final breakdown stage are discussed. The proposed continuum and kinetic approach are expected to inspire future modeling studies for the flashover mechanism and mitigation.

Preface

These proceedings are based on the program of the workshop dedicated to New Energy System and Electrical Engineering. Understanding the path from New Energy Systems to Electrical and Power Engineering will involve a strong interdisciplinary interaction among experts in theory and applications. In this workshop a particular attention was devoted to applications in New Energy System and Electrical Engineering.2022 4th International Conference on New Energy System and Electrical Engineering (NESEE 2022) took place virtually in Chongqing, China from December 9th to 11th, 2022. It can be expected that with the recent developments in the fields towards more user-friendly new energy system and electrical engineering, new energy and electrical will become a vital link in the chain of sustainable development and highly automation in the near future.Many scientists and researchers all over the world have contributed to the emerging technology of new energy and electrical engineering. At this meeting we had a comprehensive overview of these fascinating fields and of future scenarios thanks to the participation of leaders of the most important projects. Fushuan Wen, a renowned professor from Zhejiang University, China, made a keynote speech and shared his research Restoring a Faulted Power System Having Rich Renewable Energy Generation in Electricity Market Environment with us. His research domains include: a) power economics and electricity markets; b) power system investment, planning and operation optimization; c) smart grids and electric vehicles; d) power system alarm processing, fault diagnosis and system restoration; e) artificial intelligence.The plenary sessions covered a broad range of topics, as we considered it important to promote communication between the communities pursuing research in different areas of new energy and electrical engineering. The topics discussed included Energy Saving Technologies, Energy Storage Technologies, Thermal and Power Engineering, Electrical Automation and Power Engineering, Smart Grid / Power IC, Power Machinery and Engineering, etc.The NESEE conferences in the past have proven to be an important forum at which energy scientists, chemists, electrical specialists brought together a critical mass of thoughts, findings and considerations and have been endorsed by many international and national energy and electrical organizations and publishers.We hope that this NESEE 2022 conference has been a useful contribution to the fields of new energy and electrical engineering, and that it may encourage the organization of subsequent NESEE conferences on these diverse, challenging and fascinating fields.Last but not the least is our acknowledgement. We would like to thank all the participants, especially those who contributed speeches, posters and manuscripts, for making NESEE 2022 such an exciting and memorable conference. We thank the Technical Program Committee members, for putting together an outstanding program. We gratefully acknowledge the support of editors and members of the Journal of Physics: Conference Series, for their efforts in making this volume published.The Committee of NESEE 2022List of Committee Member is available in this Pdf.

Electromagnetic Design and Analysis in Electrical Power Conversion and Usage

Electromagnetics is the hidden ‘glue’ that holds together almost all electrical and electronic engineering applications [...]

Development and research trends of a polypropylene material in electrical engineering: A bibliometric mapping analysis and systematical review

In order to explore the development and research trends of polypropylene (PP) in electrical engineering, the research literature is quantitatively analyzed using a bibliometric method with the VOSviewer and CiteSpace software. First, the research literature about PP material in electrical engineering applications is collected, from 1990 to 2022. Then, by analyzing the keyword co-occurrence, keyword co-occurrence timezone, author cooperation network, and national cooperation network, the research hotspots of the PP field and its time evolutionary path and development direction are introduced. It is found that the nano-modification, mechanical, and electrical properties are the most popular research hotspots in this field. Most research studies were completed by few specific researchers. A stable cooperative group has not been formed in this field yet, indicating the necessity of further integration. Most articles about PP were published in dielectric and material journals. It is suggested that more open access journals are required to popularize the existing research results among the public and to promote the development of PP. Although the most published country is China, the United States publishes the most cited papers on average.

A comparative investigation of the chemical reduction of graphene oxide for electrical engineering applications.

The presence of oxygen-containing functional groups on the basal plane and at the edges endows graphene oxide (GO) with an insulating nature, which makes it rather unsuitable for electronic applications. Fortunately, the reduction process makes it possible to restore the sp2 conjugation. Among various protocols, chemical reduction is appealing because of its compatibility with large-scale production. Nevertheless, despite the vast number of reported chemical protocols, their comparative assessment has not yet been the subject of an in-depth investigation, rendering the establishment of a structure-performance relationship impossible. We report a systematic study on the chemical reduction of GO by exploring different reducing agents (hydrazine hydrate, sodium borohydride, ascorbic acid (AA), and sodium dithionite) and reaction times (2 or 12 hours) in order to boost the performance of chemically reduced GO (CrGO) in electronics and in electrochemical applications. In this work, we provide evidence that the optimal reduction conditions should vary depending on the chosen application, whether it is for electrical or electrochemical purposes. CrGO exhibiting a good electrical conductivity (>1800 S m-1) can be obtained by using AA (12 hours of reaction), Na2S2O4 and N2H4 (independent of the reaction time). Conversely, CrGO displaying a superior electrochemical performance (specific capacitance of 211 F g-1, and capacitance retention >99.5% after 2000 cycles) can be obtained by using NaBH4 (12 hours of reaction). Finally, the compatibility of the different CrGOs with wearable and flexible electronics is also demonstrated using skin irritation tests. The strategy described represents a significant advancement towards the development of environmentally friendly CrGOs with ad hoc properties for advanced applications in electronics and energy storage.

Smart Building Management System (SBMS) for Commercial Buildings—Key Attributes and Usage Intentions from Building Professionals’ Perspective

Smart buildings conserve energy and create a responsive, comfortable, and productive indoor environment for users and occupants. As a crucial component of smart buildings, smart building management system (SBMS) should provide a wide range of functions and bring about the intended benefits upon successful deployment. This paper identifies salient SBMS attributes and explores key factors influencing building professionals’ intention to use the system in commercial buildings. Responses were collected from 327 Hong Kong building professionals. Data were analyzed by exploratory factor analysis and structural equation modeling based on the refined Unified Theory of Acceptance and Use of Technology (UTAUT). Exploratory factor analysis shows that intelligent building operations and safety and recovery readiness are two dimensions of SBMS emerged. Specifically, intelligent building operations include intelligent and optimal scheduling of building systems, monitor and control of building facilities, having an intelligent and interactive interface, and enabling alarm settings and automatic notifications, showing the importance on the application of electrical engineering in smart building management. Structural equation model (SEM) results indicate that facilitating conditions affect habit, hedonic motivation, social influence, performance expectancy and effort expectancy. Additionally, habit, hedonic motivation and effort expectancy significantly affect building professionals’ intention to use SBMS. Practical implications of SBMS attributes for energy management and the ways in which SBMS is encouraged to be used by building professionals are given.