Electrical Engineering Problems Research Articles

A survey on dragonfly algorithm and its applications in engineering

The dragonfly algorithm was developed in 2016. It is one of the algorithms used by researchers to optimize an extensive series of uses and applications in various areas. At times, it offers superior performance compared to the most well-known optimization techniques. However, this algorithm faces several difficulties when it is utilized to enhance complex optimization problems. This work addressed the robustness of the method to solve real-world optimization issues, and its deficiency to improve complex optimization problems. This review paper shows a comprehensive investigation of the dragonfly algorithm in the engineering area. First, an overview of the algorithm is discussed. Besides, we also examined the modifications of the algorithm. The merged forms of this algorithm with different techniques and the modifications that have been done to make the algorithm perform better are addressed. Additionally, a survey on applications in the engineering area that used the dragonfly algorithm is offered. The utilized engineering applications are the applications in the field of mechanical engineering problems, electrical engineering problems, optimal parameters, economic load dispatch, and loss reduction. The algorithm is tested and evaluated against particle swarm optimization algorithm and firefly algorithm. To evaluate the ability of the dragonfly algorithm and other participated algorithms a set of traditional benchmarks (TF1-TF23) were utilized. Moreover, to examine the ability of the algorithm to optimize large-scale optimization problems CEC-C2019 benchmarks were utilized. A comparison is made between the algorithm and other metaheuristic techniques to show its ability to enhance various problems. The outcomes of the algorithm from the works that utilized the dragonfly algorithm previously and the outcomes of the benchmark test functions proved that in comparison with participated algorithms (GWO, PSO, and GA), the dragonfly algorithm owns an excellent performance, especially for small to intermediate applications. Moreover, the congestion facts of the technique and some future works are presented. The authors conducted this research to help other researchers who want to study the algorithm and utilize it to optimize engineering problems.

Coupled and Characteristic Modes of a Wideband Slot Antenna Using FEKO

Coupled Mode Theory (CMT) is a classic model that addresses many diverse problems in physics and electrical engineering. Although CMT is well-established in areas such as directional coupler design, its significance in antenna engineering is less well-recognized. Recently, Characteristic Mode Analysis (CMA) has shown how CMT quantitatively models a wide variety of multi-mode patch structures. In this paper, we extend these ideas to a double-tuned slot antenna utilizing some unique features of the method of moments code FEKO. The modeled slot antenna has a stable radiation pattern throughout its 50% impedance bandwidth. CMA decomposition indicates the antenna consists of two resonators: the slot and a lumped LC resonator that represents the feed probe. The two are electromagnetically coupled to produce broad impedance bandwidth. An equivalent circuit whose values are derived directly from the CMA results is given.

APPLICATION OF THE PICART METHOD FOR SOLVING PROBLEMS OF ELECTRICAL ENGINEERING AND ELECTRODYNAMICS

This paper presents the results of modeling transient processes in linear electrical circuits and general wave processes by the Picard method.

Convergent and Divergent Thinking Skills in Electrical Engineering Gaming Framework

This paper focuses on the participants who are categorized based on the number of times they played the same level in an online scientific game. An open-source scientific puzzle game UNTANGLED is used to perform this research. Telemetry data of more than 600 players is extracted from the database is divided into two groups: single (players who played a puzzle only one time) and multiple (players who played the same puzzle more than one time). Analysis performed on these two groups helps to examine convergent and divergent thinking skills. Statistical tests were performed to assist in learning the significance of the two groups based on dependent variables score and type of moves used in the gaming framework. This study is performed by considering more than 700 players' solutions. The findings obtained show that the single and multiple groups have no significant difference in their performance, and multiple group players obtained top scores alongside single group players. Results show that single group players could have convergent thinking that can provide only one solution for a given problem. In contrast, multiple group players could possess divergent thinking that can offer diverse solutions to the same problem from different perspectives. Finally, this paper dispenses recommendations for STEM educators and scientific game designers to develop open-ended frameworks that reward both thinking competencies. The novelty of this study is to show the consequences of including features that enhance both convergent and divergent thinking skills to solve open-ended problems in electrical engineering.  

Review of Methods for Solving Inverse Problems of Identification of the Magnetization of Permanent Magnets in Electrical Devices

The article shows the need for identification of permanent magnets by studying the distribution of magnetization over their volume by solving inverse problems. The main approaches to solving inverse problems are considered: minimization of some functional and multiple solution of the direct problem of calculating the magnetic field; solution of an ill-posed problem and determination, using regularization methods, of a pseudosolution that is stable to small perturbations. An overview of the work performed aimed at improving the theoretical and practical approaches to solving these problems is given. New mathematical models and methods for calculating the magnetic field have been developed, which provide a decrease in the number of unknown parameters, an improvement in stability and a decrease in time consumption in the problems of identifying the magnetization of permanent magnets in electrical devices. The influence of the experimental data error on the solution result is estimated. Examples of solving test problems and experimental studies are given, which have shown the effectiveness of the proposed methods and approaches. The results obtained can also be used to solve direct and inverse problems of electrical engineering.

Analysis of anchor rod failure in a guyed transmission tower: Influence of microstructures and corrosion mechanisms

The mechanical rupture of buried structural components, such as the anchor rods of guyed transmission towers, poses a significant problem in electrical and mechanical engineering. In this work, joint evaluation of anchor rods microstructures, corrosion products, and environmental analysis of corroded anchor rods in a guyed tower was conducted. Microstructural metal analysis, electron microscopy scanning, and backscattered electron diffraction (type FEG-SEM/EBSD) were used to determine the disorientation of the crystalline structure (misorientation angle <5°) and elongated grains with sizes around 2–10 µm. Predominant crystallographic planes (001) and (111) were found to be more susceptible to corrosion than (101). Researchers also observed accumulations of chloride ions in concentrations of up to 10.2% in corrosion products, and in the soil surrounding the anchor rod, chloride and sulfate ions were found in concentrations of up to 5.15% and 2.33%, respectively.

Power System Analysis Using LabVIEW

The focus of this work is on investigation of LabVIEW electric power tool in particular and LabVIEW software in general for the analysis and design of electric power systems. Here we are targeting the solution of different electrical engineering problems which we very often face in teaching the course of power system analysis. At the time being, at Zarqa University, we are preparing a self study report for submission to ABET for accreditation of electrical engineering program. ABET considers that the application of different software tools during the learning process is essential and must be covered. Thus, power system analysis course has been selected as one of the courses that are decided to reach this outcome. As a result of that, a literature survey was conducted and several relevant topics were selected to be investigated. This included the following: simulation of on-line measurement of RMS and instantaneous values of electric power, calculation of symmetrical components using matrix analysis, on-line estimation of symmetrical components, use of phasor analysis to find phasor magnitude and phase angles, conversion of star to delta and delta to star configurations, and simulation of rotating phasors. All designed virtual instruments were analyzed, tested, and chosen solved examples gave very accurate results.

IMPROVEMENT OF THE ELECTRICAL PROPERTIES OF SYNTHETIC LIQUID DIELECTRIC FOR PULSE CAPACITORS

An increase in electricity generation is possible not only through the construction of power plants, but also through the creation of fundamentally new energy sources. One of the problems of modern electrical engineering is to ensure the reliability of the operation of capacitors at electric field strengths exceeding I50-200MV. In the domestic and foreign capacitor industry, for heavy pulse modes, castor oil (CO) is used as a liquid impregnation. The development of a method for producing a substitute for natural castor oil, which is a universal impregnating liquid in capacitors, is an urgent problem in the electrical industry. Thus, we have developed a method for the production of acetoxymethyl-w.hexyl-o-xylene, the electrophysical properties of which make it possible to use it as an environmentally friendly and promising substitute for natural castor oil. However, there was a problem of stabilization, since compounds of the ester type have (as impregnating liquids in capacitors) a disadvantage, which consists in their sensitivity to light hydrolysis and atmospheric effects. Ester exhibits high stability with respect to air up to 200 °С, therefore, inhibition by the addition of antioxidants is required is not new.&#x0D; In this work developed the basic electrophysical properties of the ester-acetoxymethyl-secondary hexyl-o-xyleole; methods for its purification and stabilization. There were chosen the adsorption method of thermo-oxidative stabilization to clean dielectric fluid from conductive impurities.&#x0D; As a result of the electrophysical characteristics of the acetoxymethyl-secondary hexyl-o-xyleole ester, as well as the method of its purification using alumina, and hydrogenation on a catalyst representing 0.2 % palladium on alumina and stabilization using additives NG-2246. As a result of the research, it was possible to obtain an ester with improved electrophysical parameters

Improve the Teaching Quality of Electrical Engineering and Automation

At present, many schools have not yet established a complete electrical engineering and automation professional teaching system, and the construction of professional teacher teams is relatively lacking. Therefore, the quality of professional teaching is uneven. Under the background of new engineering courses, electrical engineering and automation majors put forward clear requirements for students’ application ability and comprehensive ability, and many schools have begun to reform professional practice courses. Based on an in-depth analysis of the current situation and problems of electrical engineering and automation majors, this article discusses methods to improve the quality of electrical engineering and automation majors.

A novel grid-oriented dynamic weight parameter based improved variant of Jaya algorithm

Jaya algorithm (JA) is a single-step metaheuristic optimization technique that is free from algorithm-specific parameters. Regardless of its simplicity, JA proved its effective performance against the variety of optimization algorithms (Du et al., 2018). However, like other swarm-based optimization techniques, the JA also suffers from the inadequacies of slow or premature convergence (Farah and Belazi, 2018). In this study, an improved variant of JA (IJaya) is proposed whose functioning depends on the randomly initiated bounds based grid-oriented weight parameters. Initially, aiming to balance the global exploration and local exploitation capabilities of JA, a dynamic weight parameter is introduced as a varying coefficient for the entire solution updating expression of JA. Then, to maintain the population diversity and to mitigate the complexity of parameter tuning, the introduced weight parameter is dealt with the randomly selected parameter bounds based grid-search mechanism. The proposed IJaya algorithm is benchmarked on well-known 15 unconstrained mathematical test functions, and its performance is analyzed against the standard JA, one modified variant of JA, some well-known state-of-the-art, and few newly introduced optimization algorithms. Furthermore, the non-parametric Friedman and Quade rank tests are also conducted which confirmed the superiority of proposed IJaya both in convergence rate and solution quality. The paper also presents the results obtained by IJaya in two classical structural design problems (a cantilever beam and a 3-bar truss) and a real-world electrical power engineering problem. Numerical results clearly prove the efficiency of the proposed algorithm.

Preface

Today we are in a world of information society where we are required to be able to create, access, develop, use, and share information and knowledge individually or in groups. A high potential of the community needs to support the ability and carrying capacity of sustainable development and improve the quality of life. Science is an essential key in the development of industry and information society. Smart work is one way to guarantee an increase in living standards. The industry has changed along with the digitization era, which restructured quickly by embedding and connecting among factories. It has produced an industrial revolution and opportunities for the automation of the new industrialization process. At the same time, competition from the outside world is getting tougher by utilizing knowledge content even though sustainable production can be an advantage in the future.Industry era 4.0 utilizes companies to play the role of digital transformation leaders and to exploit the potential of digitalization. Sustainable production will increase resource efficiency and environmental considerations in competition. This demand will have an impact on solving problems in human life, digital computing, mechanical engineering, electrical, metal, and material engineering, and process engineering, including process complexity, continuous processes in programming, and machine operations. And also it is the basis for supporting interconnection, understanding business and technology, identifying and solving problems, thinking deductively and experimentally, understanding soft skills as well as the importance of technical skills.We hope that these published papers can play a role in the development of the world by empowering the development of science and technology in the competitive industry 4.0.

Equações diferenciais para resolução do circuito elétrico LRC

Studies about differential equations provide many mathematical instruments that aid the insight of many practical problems. The goal of this paper is to obtain a differential equation that describes an Electrical Engineering problem, then to define the solution of this equation using analytical methods and to compare theoretical and experimental results. Firstly, the second order differential equation with constant coefficients and the analytical method to obtain the respective solution will be studied; later this solution will be applied in the problem of an LRC electrical circuit with simple mesh with an inductor (L), a resistor (R), a capacitor (C) and an electromotive source. The goal is to solve the differential equation to define the charge, in function of the time, between the capacitor and the inductor. The solution is obtained from the homogeneous solution (admitting a solution in the exponential form) and the particular solution (using the undetermined coefficients method, due to function form). Initial conditions for the initial charge and the initial current can be used, with the analytical methods, to find the particular solution of the problem.

Electric Tree Characteristics of Glass Fiber Reinforced Epoxy Insulation Composites with Different Contents

Electric tree aging due to the action of long-term partial discharge stress of epoxy resin casting insulation is a major problem in electrical engineering. On the discharge experimental platform, initiation and culture experiments of the electric trees were carried out at a power frequency voltage of 20 kV. The mass fractions of the spherical glass fibers were 0, 0.5, 1, 2 and 3 %. The results showed that the electrical dendritic process of epoxy resin experienced initiation, growth, lag and burst periods, the phase maps of the corresponding partial discharges in the four periods were all “mountain-like”. The electric tree of pure epoxy resin showed a typical dendritic structure, after the glass fiber was properly added, the electric tree became lighter in color with a more complicated shape, the damage also became more serious, however, the growth of the electric branch was suppressed. The electric tree aging channel of the epoxy resin appeared black and under microscopy the micro-branched channel wall appeared white. When the amount of glass fiber was 2 %, the initiation time of the electric trees was prolonged, the growth rate of the electric trees decreased and suppressing development of the electric tree branches was optimal.

От матроидов в задачах электротехники и механики — к решению прикладных экономических задач

От матроидов в задачах электротехники и механики — к решению прикладных экономических задач

An intuitive, application-based, simulation-driven approach to teaching probability and random processes

Probability and random processes is considered by students to be conceptually one of the most difficult subjects in the undergraduate electrical and computer engineering curriculum. There are numerous reasons for this difficulty encountered by the students. First off, humans are not innately good at probabilistic intuition. Traditionally, this subject has been introduced in a very abstract manner without emphasis on real-world applications from electrical and computer engineering discipline. In addition, extensive use of interactive simulation and visualization tools, offering an alternative way of developing probabilistic intuition, is usually missing from traditional course offerings. This paper presents a unique pedagogical approach to teaching an introductory probability course offered to electrical and computer engineering juniors. The salient features of the proposed pedagogical approach include more emphasis on real-world electrical and computer engineering problems that show the applications of abstract probabilistic concepts; extensive hands-on and interactive MATLAB® simulations of real-world electrical and computer engineering problems that are tightly integrated into the curriculum; highlighting the frequentist approach to build probabilistic intuition using simulations; concrete examples showing how naive probabilistic intuition can be erroneous and how to develop correct probabilistic intuition based on systematically modeling, simulating, and analyzing a problem; and application-based simulations driving the abstract theory rather than the other way around. This pedagogical approach was implemented in a course offered to electrical and computer engineering undergraduates at Purdue University Northwest. The paper presents a concrete example illustrating how the salient features of the proposed pedagogical approach were implemented as part of this course and student data from the courses to validate the efficacy of the proposed approach.

Analysis of Temperature Conditions Influence on Cables Insulation Operation Life

Electrical equipment fault current interruptions reduce is one of the most important problems of electrical power engineering and diagnostics. Power cables operation life is one of the parameters mostly affecting fault current interruptions on cables. The paper describes the research on thermal degradation of low voltage cables insulating materials and its influence on insulation operation life. The known mathematical models of the insulation aging depending on its temperature are considered. Low voltage cables have an insignificant electrical aging influence, so it is assumed that such cables aging mostly caused by their thermal operating conditions. Experimental research of cables insulation temperature monitoring is performed. Seven weeks of the experiment showed a temperature change between 17˚C and 27˚C. The mean temperature was 21.9˚C. Assuming that cable has normal operation life with an average temperature of 20˚C and accounting thermal conditions cable insulation operation life is reduced for about 20%. Such operation life reduce is significant and shows a considerable influence of insulating material thermal deterioration.

A High-Performance Stochastic Fractal Search Algorithm for Optimal Generation Dispatch Problem

This paper proposes applications of a modified stochastic fractal search algorithm (MSFS) to solve the economic load dispatch problem (ELD) in which valve-point effects, prohibited operating zones, power losses in all conductors, multi-fuel sources and other constraints of power system are taken into consideration. The proposed method is first developed in the study by performing two modifications on two procedures of new solution generation from conventional stochastic fractal search (SFS). The first modification is used to change the strategy of producing new solutions of the first and the second update procedures while the second one is to newly update the worst solutions in the first update process and the best solutions in the second update process. These modifications have major influence on the solution search performance of the proposed method. All improvements of the proposed method can be illustrated by solving and analyzing results from various test systems with different system scales including 3-unit, 6-unit, 10-unit, and 20-unit systems. Comparison of results obtained by MSFS, SFS, and other existing methods indicates that the proposed MSFS method is more effective and robust than compared methods in terms of solution quality, high-quality solution search stability and convergence process. Consequently, the proposed method should be used as a very favorable optimization method for the ELD problem and it should be tried for other optimization problems in electrical engineering.

Improvements of bat algorithm using crossover technique and hybridization with Nelder-Mead simplex method

Purpose This study aims to improve the bat algorithm (BA) performance for solving optimization problems in electrical engineering. Design/methodology/approach For this task, two strategies were investigated. The first one is based on including the crossover technique into classical BA, in the same manner as in the genetic algorithm method. Therefore, the newly generated version of BA is called the crossover–bat algorithm (C-BA). In the second strategy, a hybridization of the BA with the Nelder–Mead (NM) simplex method was performed; it gives the NM-BA algorithm. Findings First, the proposed strategies were applied to solve a set of two standard benchmark problems; then, they were applied to solve the TEAM workshop problem 25, where an electromagnetic field was computed by use of the 2D non-linear finite element method. Both optimization algorithms and finite element computation tool were implemented under MATLAB. Originality/value The two proposed optimization strategies, C-BA and NM-BA, have allowed good improvements of classical BA, generally known for its poor solution quality and slow convergence rate.

Stable Non-symmetric Coupling of the Finite Volume Method and the Boundary Element Method for Convection-Dominated Parabolic-Elliptic Interface Problems

Abstract Many problems in electrical engineering or fluid mechanics can be modeled by parabolic-elliptic interface problems, where the domain for the exterior elliptic problem might be unbounded. A possibility to solve this class of problems numerically is the non-symmetric coupling of finite elements (FEM) and boundary elements (BEM) analyzed in [H. Egger, C. Erath and R. Schorr, On the nonsymmetric coupling method for parabolic-elliptic interface problems, SIAM J. Numer. Anal. 56 2018, 6, 3510–3533]. If, for example, the interior problem represents a fluid, this method is not appropriate since FEM in general lacks conservation of numerical fluxes and in case of convection dominance also stability. A possible remedy to guarantee both is the use of the vertex-centered finite volume method (FVM) with an upwind stabilization option. Thus, we propose a (non-symmetric) coupling of FVM and BEM for a semi-discretization of the underlying problem. For the subsequent time discretization we introduce two options: a variant of the backward Euler method which allows us to develop an analysis under minimal regularity assumptions and the classical backward Euler method. We analyze both, the semi-discrete and the fully-discrete system, in terms of convergence and error estimates. Some numerical examples illustrate the theoretical findings and give some ideas for practical applications.

A novel meta-heuristic optimization method based on golden ratio in nature

A novel parameter-free meta-heuristic optimization algorithm known as the golden ratio optimization method (GROM) is proposed. The proposed algorithm is inspired by the golden ratio of plant and animal growth which is formulated by the well-known mathematician Fibonacci. He introduced a series of numbers in which a number (except the first two numbers) is equal to the sum of the two previous numbers. In this series, the ratio of two consecutive numbers is almost the same for all the numbers and is known as golden ratio. This ratio can be extensively found in nature such as snail lacquer part and foliage growth of trees. The proposed approach employed this golden ratio to update the solutions in an optimization algorithm. In the proposed method, the solutions are updated in two different phases to achieve the global best answer. There is no need for any parameter tuning, and the implementation of the proposed method is very simple. In order to evaluate the proposed method, 29 well-known benchmark test functions and also 5 classical engineering optimization problems including 4 mechanical engineering problems and 1 electrical engineering problem are employed. Using several test functions, the performance of the proposed method in solving different problems including discrete, continuous, high dimension, and high constraints problems is testified. The results of the proposed method are compared with those of 11 well-regarded state-of-the-art optimization algorithms. The comparisons are made from different aspects such as the final obtained answer, the speed and behavior of convergence, and CPU time consumption. Superiority of the purposed method from different points of views can be concluded by means of comparisons.