Electrical Elements Research Articles

Detection and Quantification of Asymmetrically Located Structural Damages by Mode Converted Guided Waves Using Piezo Electric Elements

Though damage identification using guided waves generated using ultrasonics is well proven, its usage for structural health monitoring poses difficulties. Piezo electric actuation and sensing overcomes this difficulty to some extent. In this work, usage of such guided waves for damage identification is investigated. Piezo electric wafer transducers are used for generating and sensing the guided waves. Presence of multiple modes and comparatively higher speeds of the guided waves throw up difficulties in damage identification. It is shown here that this problem can be addressed by considering different sensor location with respect to the damage with suitable interpretation of the results. Usage of fundamental antisymmetric (Ao) mode is found to be more suitable in localizing the damage compared to the fundamental symmetric (So) mode. Asymmetrically located damage causes mode conversion. It is demonstrated in this work that the mode converted guided wave (So) could be advantageously used for identification, localization, and quantification of the damage. Damage identification and localization schemes are evolved based on the location of the sensors with respect to the damage. It is shown that the reduction in the magnitude of the mode converted wave can be utilized for assessing the depth of the damage. 3D finite element based numerical models incorporating a PZT sensor are developed and validated with experimental results in terms of the characteristics of the waves, mode conversion due to damage and influence of the defect size on the received signals which are necessary for quantification of the damage.

Selecting the PID Controller Settings for an Automatic Generation Control Device in a Power System

The integration of renewable generation facilities into integrated power systems entails new challenges for maintaining a reliable and safe electric power infrastructure. It is necessary to expand the use of automatic generation control devices to ensure the ability to control the modes of power systems with a significant share of renewable energy sources. The generation control devices can be used not only for frequency control, but also for maintaining the inter-area wheeling in interconnected power systems. The article suggests application of the particle swarm method, which is one of evolutionary optimization methods, to find optimal parameter settings for proportional-integral-differentiating (PID) controllers of the automatic generation control device. The mathematical description of electric power system elements is given, and a structure of automatic generation control is given. The tuning parameters of the PID controllers of the automatic generation control device based on the particle swarm method, as well as some of classical optimization methods, have been determined. The results of tuning PID controllers obtained by different methods in the form of frequency variation characteristics in power system parts, as well as the torques of an equivalent steam turbine in response to power fluctuations in one of the power system parts are compared.

Optimization of a phase change material enhanced low-concentration photovoltaic/thermal module

This paper presents a simulation and optimization study of a nanoparticle-enhanced phase change material (PCM) assisted low-concentration photovoltaic/thermal (LCPV/T) module. An optical, electrical, and thermal model coupling finite element simulation is developed, with the thickness of the PCM, the mass fraction of nanoparticles in the heat transfer fluid and PCM, and the velocity of the heat transfer fluid as optimization parameters. To improve the efficiency of the optimization process, a response surface methodology is used to investigate the polynomial relationship between the parameters and module performance. The significance level and average error of each polynomial are found to be lower than 0.05 and 2.5%, respectively, indicating their statistical significance and accurate prediction of module performance. The fitting polynomials are used to optimize and analyze the module, and the results show maximum values of output thermal energy, output thermal exergy, output electrical energy/exergy, total output energy, and total output exergy of 573.11 W, 13.05 W, 110.40 W, 869.93 W, and 121.08 W, respectively. Comparison with the previously designed module revealed that the newly designed module demonstrated better electrical output performance, providing valuable guidance for the energy supply of zero-carbon buildings.

Employing the Peltier Effect to Control Motor Operating Temperatures

Electrical insulation failure is the most common failure mechanism in electrical machines (motors and generators). High temperatures and/or temperature gradients (HTTG) are the main drivers of insulation failure in electrical machines. HTTG combine with and augment other destructive effects from over-voltage, to voltage transients, overload and load variations, poor construction techniques, and thermal cycling. These operating conditions cause insulation damage that leads to electrical insulation failure. The insulation failure process is greatly accelerated by pollutants and moisture absorption. A simple and robust way to reduce HTTG and moisture adsorption is by maintaining constant internal temperatures. The current method to maintain elevated internal temperatures and reduce condensation issues is by internal electrical heating elements. This paper examines the effectiveness of applying thermoelectric coolers (TECs), solid-state heat pumps (Peltier devices), as heaters to raise a motor’s internal temperature by pumping heat into the motor core rather than heating the internal air. TEC technology is relatively new, and the application of TECs to heat a motor’s internal volume has not previously been explored. In this paper, we explore the hypothesis that TECs can pump heat into a motor when out of service, reducing the HTTG by maintaining high winding slot temperatures and eliminating condensation issues. This paper describes a test motor setup with simple resistive heating (traditional method), compared with the application of TECs with heat sinks, heat pipes, and a water circulation heat exchanger, to gauge the capability of TECs to heat the inner core or winding area. In this paper, we demonstrate the full integration of TECs into a motor. The results show that each of the systems incorporating the TECs would effectively pump heat into the core and keep the winding hot, eliminating condensation issues and water ingress due to thermal cycling.

CO2-neutral Process Heating for Carburizing Furnaces – an Ecological Analysis*

Abstract In order to achieve the goal of a massive reduction of CO2-emissions, fossil fuels have to be substituted. In Germany, continuous carburizing furnaces for high capacities are almost exclusively fired by natural gas due to the lower energy costs. Electrical heating and hydrogen combustion are obvious alternatives. While electrical heating elements are state-of-the-art for these types of furnaces, hydrogen combustion has not been investigated. Furthermore, these two alternatives strongly depend on the specific energy mix, which determines the CO2-emissions. This case study compares different process heat generation options for continuous ring hearth furnaces for carburizing automotive steel parts by a quantitative approach. The investigated alternatives are natural gas/air heating as the reference, electrical heating and hydrogen/air heating. Besides the energy balances, primary energy consumption and resulting CO2-emissions are calculated. Furthermore, possible developments until 2050 are analysed. The results show that both alternative cases have a high potential to decrease CO2-emissions which strongly depend on the development of the energy mix and, therefore, the future expansion of renewable energy sources.

ARTIFICIAL INTELLIGENCE FOR CONTROL SMALL HYDROELECTRIC POWER PLANTS

The problem of providing cheap electricity to both industrial enterprises and settlements has been and remains very relevant. More than 1 million people live in decentralized power supply zones. This is especially important for the remote areas of southern Kazakhstan, where there is no developed power transmission network, and the population receives electricity for 3-4 hours a day from a diesel-electric power station (DPP). The construction of small hydroelectric power plants (SHPPs) can change the living conditions of these people, ensure the energy security of the regions and contribute to the development of the economy. At present, when solving problems related to the reconstruction and construction of new small hydropower plants, it is necessary to apply inexpensive and effective solutions for automation and remote control of power plants without the constant presence of maintenance personnel. To effectively control and protect SHPs, a relatively large amount of functionality must be provided compared to larger power plants. A standardized intelligent electronic device (IED) can provide autonomous operation and prioritize safe water management. The IED shall be compact and integrated with the control of electrical and mechanical elements, including the water supply, communication, monitoring and protection system for small hydro power plants.

Study the Effect of the Laser on the Structural and Electrical Properties of the Compound Tl2-xHgxBa2-ySryCa2Cu3O10 + δ Superior Electrical Conductivity at High Temperatures

This study included the preparation of composite samples (Tl2-xHgxBa2-ySryCa2Cu3O10+δ) in various concentrations of x where (x=0,0.1,0.2,0.3,0.4,0.5). by solid state reaction method and under hydrostatic pressure (ton /cm2 8 interaction) and temperature annealing (850°C), and determine the effect of the laser on the structural and electrical properties elements in the compound, Observed by examining the XRD The best ratio of compensation for x is 0.2 as the value of a= b = 5.3899 (Å), c = 36.21 (Å) show that the installation of Teragonal structure, the study found that oxygen played an important role in increasing the critical temperature. When you shine a CO2 laser on the samples in order to recognize the effect of the laser on these samples showed the study of X-ray diffraction of these samples when preparing samples with different concentrations of the values ​​of x, the best value of compensation is 0.2 which showed an increase in the values ​​of the dimensions of the unit cell a = b = 5.3929 (Å), c = 36.238 (Å) as well as we have noticed in the Teragonal structure of the compound and took the boat the best role in the crystal structure. When examining the electrical characteristics for different values of the values of (x) found that the best degree of critical temperature at x = 0.2 is TC = 142 K and after shedding CO2 laser on the prepared forms note the increase in the critical temperature at x= 0.2 is TC = 144 K. The screening samples by atomic force microscopy three-dimensional (AFM), and also has a study and examination of the crystal structure of the samples by scanning electron microscope (SEM) and know the percentages elements in the compound and, the effect of annealing temperature .the pressure applied, and to quantify the concentration of elements in the composite.

Physicochemical Modeling of Electrochemical Impedance in Solid-State Supercapacitors.

Solid-state supercapacitors (SSCs) consist of porous carbon electrodes and gel-polymer electrolytes and are used in novel energy storage applications. The current study aims to simulate the impedance of SSCs using a clearly defined equivalent circuit (EC) model with the ultimate goal of improving their performance. To this end, a conventional mathematical and a physicochemical model were adapted. The impedance was measured by electrochemical impedance spectroscopy (EIS). An EC consisting of electrical elements was introduced for each modeling approach. The mathematical model was purely based on a best-fit method and utilized an EC with intuitive elements. In contrast, the physicochemical model was motivated by advanced theories and allowed meaningful associations with properties at the electrode, the electrolyte, and their interface. The physicochemical model showed a higher approximation ability (relative error of 3.7%) due to the interface impedance integration in a more complex circuit design. However, this model required more modeling and optimization effort. Moreover, the fitted parameters differed from the analytically calculated ones due to uncertainties in the SSC's microscale configuration, which need further investigations. Nevertheless, the results show that the proposed physicochemical model is promising in simulating EIS data of SSCs with the additional advantage of utilizing well-reasoned property-based EC elements.

Design principles for a single-process 3D-printed stacked dielectric actuators — Theory and experiment

Fully 3D-printed smart structures have attracted a lot of research interest; new technologies, materials, and methods for 3D-printed functional structures such as sensors, actuators, generators, and batteries are being researched. Recently, a fully 3D-printed, dynamic dielectric actuator fabricated in a single process with multi-material thermoplastic filament extrusion was presented. However, the effects of design parameters on the dynamic electromechanical properties of the printed actuator were not yet researched.To achieve the required performance and dynamic properties of an individualized, 3D-printed actuator, the electromechanical properties must be related to the theoretical design parameters. This requires research into the properties of 3D-printed materials and the electromechanical modeling of the 3D-printed actuator.In this research, an analytical, electromechanical model is introduced, consisting of electrical and mechanical models, and electromechanical coupling. The model consists of basic electrical and dynamic lumped elements, which facilitates the reproducibility and extensibility of the model. The electrical and electromechanical model have been experimentally validated in a free-displacement and a blocked-force boundary condition.This research leads to the identification of design principles and the ability to customize and adapt the 3D-printed actuators to specific dynamic applications.

Portable Iontophoresis Device for Efficient Drug Delivery.

The timely delivery of drugs to specific locations in the body is imperative to ensure the efficacy of treatment. This study introduces a portable facial device that can deliver drugs efficiently using iontophoresis. Two types of power supplies-direct current and pulse ionization supplies-were manufactured by injection molding. Electrical stimulation elements, which contained Ag metal wires, were woven into facial mask packs. The diffusion phenomenon in the skin and iontophoresis were numerically modeled. Injection molding was simulated before the device was manufactured. Analysis using rhodamine B demonstrated a remarkable increase in the moisture content of the skin and effective absorption of the drug under an applied electric field upon the application of iontophoresis. The proposed concept and design constitute a new method of achieving effective drug absorption with wearable devices.

Electric Vehicles and the Use of Demand Projection Models: A Systematic Mapping of Studies

In today’s world, electric vehicles have become a real solution to the problem of pollution caused by petrol and diesel-powered vehicles. However, incorporating them successfully into the global vehicle park poses new challenges. Some of these challenges have to do with meeting the electricity demand, providing the physical installations for charging, and the size and capacity of the electric grid required to deliver the necessary supply. Solving these new problems requires determining or projecting the electrical and/or physical requirements involved, but there is no single model or methodology to do this, nor any single document which summarizes the existing information. To address this situation, this work presents the result of a systematic mapping study that seeks to provide organized information about the (mathematical) models for the demand arising from electric vehicles, as well as to answer a series of questions posed for this research. The results obtained show that there is a wide variety of models used to determine demand requirements –of either physical or electrical elements– in which mathematical modelling and operations research tools are normally used. Other results indicate that demand models are mainly focused on the electrical requirements rather than on physical ones, and that, in most cases, the type of vehicle for which the demand is studied is not mentioned.

Technologies and materials for the assembly and installation of electrical elements

The article is devoted to the creation of a multifunctional machine for microsoldering and mounting of electrical components for the board. The problems of designing machine tools, existing analogues and prototypes are considered, as well as technologies and materials for fastening electrical elements and connecting them to each other are selected. Keywords machine tool manufacture, automation, analogues, soldering, electronics, electrical mounting, flux, solder, jumper

Экстраполяция опытных данных по пиролизу метана на оптимальные условия получения водорода и этилена

Data on non-catalytic pipe pyrolysis of methane are considered. The parameters of kinetic equations are given, which ensure coincidence with the data in a wide range of temperatures (up to 1600 0C) and pressures (up to 30 atm). The equations of gas dynamics and energy are formulated, solutions of the equations of pipe pyrolysisare given for various methods of heat flow supply to the tube wall. The cases of setting a linear density of thermal power on the surface of a pyrolysis pipe obtained due to the radiation of gas burners or electric heating elements are considered. The limiting possibilities of pipe pyrolysis of methane for the production of hydrogen and ethylene as the main products are shown. The energy consumption of the proposed and known options is comparedon the example of the problem of obtaining hydrogen for the urban ecotransport of Moscow.

An Enhanced-Sensitivity Tangential Electric Field Probe With Tunable Resonant Frequency

A novel enhanced-sensitivity tangential <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -field probe with tunable resonant frequency is proposed in this paper. This <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -field probe consists of a front-end electric dipole induction part, tunable coupling resonators, a balun transmission section, and a coplanar waveguide transmission part. By introducing an improved electric dipole-induced element and resonant transmission, the detection sensitivity of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -field probe can be significantly improved. Varactor diodes are loaded into the coupling resonators to achieve an adjustable resonant center frequency, thereby minimizing the contradiction between the high sensitivity and test bandwidth of the resonant <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -field probe. A prototype of this tunable resonant frequency probe was fabricated and measured. When the reverse bias voltage applied to the varactors was tuned from 0 V to 20 V, the probe could obtain enhanced-sensitivity tangential <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -field detection within the frequency band of 1.61-2.30 GHz. Moreover, this probe was also adopted to measure the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -field components in some areas of the microstrip line and antenna based on FR4. This probe can improve detection efficiency and reduce test costs on the premise of enhanced sensitivity detection. It has broad application prospects for near-field measurement in the future.

DEVELOPMENT AND USE OF A MODULAR HEATER OF INTERNAL COMBUSTION ENGINE FOR MULTI-PURPOSE VEHICLES

The operation of power facilities in winter, characterized by low ambient temperatures reaching minus 50 degrees Celsius, requires their adaptation to work in such conditions. With a decrease in the ambient temperature, the vaporization of gasoline also worsens, the ignition conditions of the working mixture in the cylinders of diesel cars change, the power consumption of batteries increases when starting a cold engine. (Research purpose) The research purpose is conducting a patent search and creating a reliable, highly efficient thermoelectric heating device with a low cost, which allows improving the performance of a power vehicle (car) working in winter conditions. (Materials and methods) The KamAZ-55111 car, adapted to low-temperature conditions of use, with a thermoelectric heating module installed, was studied. The tests were carried out according to generally accepted general and particular methods using specialized mathematical calculation programs, experimental modeling and regression analysis methods. (Results and discussion) It was determined that when the engine is running, the exhaust gases heat the exhaust pipe and the surface of the device installed on it with the Peltier element. When the vehicle is moving, the temperature difference increases with the flow of cold air, which provides an increase in electrical energy for charging the traction alkaline battery, then through the controller to the electric heating element for heating and maintaining the optimal temperature of the working fluids and components of the car. It was found that the heating time of the hydraulic cylinder working fluid from minus 40 to plus 30 degrees Celsius was 0.5 hours. (Conclusions) The proposed device made it possible to warm up and maintain the optimal engine start temperature. In 0.5 hours, we received an economic effect in the amount of 38.5 thousand rubles.

A STUDY OF IMPACT OF STRONG MAGNETIC STORM ON CONSOLIDATED POWER SYSTEM OF CENTRE OF RUSSIA

This article represents results of simulation of geomagnetically induced current impact on Consolidated power system of Centre of Russia during strong magnetic storm. The paper shows that complex of factors appears during this impact which can induce progress of blackout: significant decrease of voltage on a set of electrical power elements, mass cutoff of power transmission lines under the influence of relay protection and dangerous heating of construction elements of power transformers.

Learning With STEM Is Not Difficult At All!

The aim of this study is to teach how to design a circuit using simple electrical circuit elements with a STEM activity conducted with 4 students with learning difficulties studying at a primary school located in the southern region of Anatolia. The study was carried out in the form of extracurricular activities focused on science lessons on the subject of simple electrical circuits for 8 class hours over a period of 2 weeks. After the quantitative stage of the study, which was designed as a mixed method design, the qualitative stage was conducted In the study, a STEM process rubric was used as the quantitative data collection tool, while an observation form and interview form were used as the qualitative data collection tools. At the end of the study, it was determined through interviews that the STEM activities made a significant academic contribution to the participants, that they had a lot of fun while learning, and that they did not easily forget what they had learned. The participants, who stated that the activities benefited them academically in science and mathematics, also reported that they used the knowledge about science and mathematics they gained here in other subjects as well..

Ka-Band Huygens Antenna Array With Very High Aperture Efficiency and Low Sidelobes

A Ka-band Huygens antenna array with extremely high aperture efficiency (AE) and low sidelobe levels is reported for 5G millimeter-wave (mm-wave) wireless applications. The basic array element is an innovative Huygens subarray consisting of two open rectangular waveguides that form an aperture consisting of a 1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 2 set of orthogonal, tightly coupled electric and magnetic elements separated by a virtual gap that are balanced, in- phase, and radiate Huygens cardioid patterns. A larger 8 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times16$ </tex-math></inline-formula> element array is then realized with 64 of these 1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 2 subarrays. With excitations of equal amplitude, the full broadside-radiating array achieves an AE up to 97.5% in the operating bandwidth, which is very close to the 100% limit associated with an ideal uniform aperture distribution. Moreover, a highly efficient and compact feed network with tapered-amplitude and in- phase excitations from the array center to its edges is designed to achieve sidelobe and backlobe levels less than −20 dB. The −10 dB impedance bandwidth covers 26.7–29.65 GHz, and the peak realized AE (RAE) reaches 82%. A full-aluminum array prototype was fabricated with standard machining processes and tested. The measured performance characteristics agree well with their simulated values, confirming the efficacy of their designs.

Mathematical model of a thermoelectric system for cooling discrete electric radio elements

Mathematical model of a thermoelectric system for cooling discrete electric radio elements

Optimization and modeling of electric generators elements of wind power plants

The issues of improving the exploitation properties of renewable energy equipment are considered. The concept of improving power electronics and the design of a wind farm is defined. A model and algorithms for controlling the power of an electric generator have been developed. The results of computer modeling are presented.