Electrical Diagram Research Articles

Determination and control of ion parameters in a complex plasma of a DC discharge

Complex plasmas, comprising a low-pressure DC discharge plasma and charged microparticles, form traps that can accumulate and localize ions. A loss of ions and electrons always occurs on the surfaces of the microparticles, which can lead to a decrease in the ion and electron densities in the plasma bulk. However, in most cases, the collective effect of the interaction between the discharge plasma and the dust cloud leads to an increase in the ion density—both around and inside the dust cloud—in comparison with that in pure plasma at the same discharge currents. Complex plasmas are open dissipative synergetic systems. Feedback between plasma processes allows one to control their properties using the external influences of various physical fields. Such influences thus represent a tool for controlling the dust cloud parameters and the ion density. In this letter, we report a method for determining the ion density inside a dust cloud using an electric field-current diagram (ECD). This method is based on the statement that only a single electric field can relate the particular values of the ion density, the discharge, and the dust cloud parameters. Our method includes a procedure for superimposing the ECD on the ion density-current diagram. To calculate the plasma parameters, a fluid model of a DC discharge with microparticles is employed. The method proposed herein allows us to find the conditions under which the ion density in a plasma with microparticles is less than that in pure plasma without microparticles—or vice versa, increases up to five times.

ABOUT ONE METHOD OF IMPROVING THE STATIC CHARACTERISTIC MAGNETOELASTIC SENSORS

The article is devoted to improving the static characteristics of magnetoelastic sensors. Using the energyinformational method, techniques for improving the static characteristic are identified. By implementing these techniques, the design of a magnetoelastic sensor is proposed. The design scheme of the proposed magnetoelastic sensor, the electrical connection diagram of the sections of the measuring windings and the principle of operation of the sensor are given. An expression of the static characteristic for estimating its degree of nonlinearity is obtained.

Modeling of a hybrid energy system, Photovoltaic and Generator (PV/GE) at the Higher Institute of Technology of Mamou, Guinea

This present work was carried out at the Energy Department of the Higher Institute of Technology of Mamou and at the Applied Energy Education and Research Laboratory of the Faculty of Sciences of the Gamal Abdel Nasser University of Conakry, Guinea. Given the solar energy potential available to the continent, Hybrid Photovoltaic Power Systems and Generating Sets could constitute a suitable technological solution for the supply of electrical energy in isolated sites. This study led to the following results: average unfavorable solar irradiation in June (4.16 kWh/m2.d); the building's electrical load balance is 254760 Wh/d; the sizing of the photovoltaic field (the type of panels chosen Cip-60-270, the peak power of the PV field 59435.420 Wp, the number of panels 220 including 2 in series and 110 in parallel); the C4000-48 type inverter-chargers, 62 in number to achieve a power of 40 nickel-cadmium 1.2 V type accumulators in series in 140 batteries connected in parallel, the voltage drop in the cables is between 0.01 and 0.02. The electrical diagram of the installation is done.

High-speed and high-power germanium photodetector with a lateral silicon nitride waveguide

Up to now, the light coupling schemes of germanium-on-silicon photodetectors (Ge-on-Si PDs) could be divided into three main categories: (1) vertical (or normal-incidence) illumination, which can be from the top or back of the wafer/chip, and waveguide-integrated coupling including (2) butt coupling and (3) evanescent coupling. In evanescent coupling the input waveguide can be positioned on top, at the bottom, or lateral to the absorber. Here, to the best of our knowledge, we propose the first concept of Ge-on-Si PD with double lateral silicon nitride ( Si 3 N 4 ) waveguides, which can serve as a novel waveguide-integrated coupling configuration: double lateral coupling. The Ge-on-Si PD with double lateral Si 3 N 4 waveguides features uniform optical field distribution in the Ge region, which is very beneficial to improving the operation speed for high input power. The proposed Ge-on-Si PD is comprehensively characterized by static and dynamic measurements. The typical internal responsivity is evaluated to be 0.52 A/W at an input power of 25 mW. The equivalent circuit model and theoretical 3 dB opto-electrical (OE) bandwidth investigation of Ge-on-Si PD with lateral coupling are implemented. Based on the small-signal (S21) radio-frequency measurements, under 4 mA photocurrent, a 60 GHz bandwidth operating at − 3 V bias voltage is demonstrated. When the photocurrent is up to 12 mA, the 3 dB OE bandwidth still has 36 GHz. With 1 mA photocurrent, the 70, 80, 90, and 100 Gbit/s non-return-to-zero (NRZ) and 100, 120, 140, and 150 Gbit/s four-level pulse amplitude modulation clear openings of eye diagrams are experimentally obtained without utilizing any offline digital signal processing at the receiver side. In order to verify the high-power handling performance in high-speed data transmission, we investigate the eye diagram variations with the increase of photocurrents. The clear open electrical eye diagrams of 60 Gbit/s NRZ under 20 mA photocurrent are also obtained. Overall, the proposed lateral Si 3 N 4 waveguide structure is flexibly extendable to a light coupling configuration of PDs, which makes it very attractive for developing high-performance silicon photonic integrated circuits in the future.

Lights Out on graphs

We model the Lights Out game on general simple graphs in the framework of linear algebra over the field mathbb{F}_{2}. Based upon a version of the Fredholm alternative, we introduce a separating invariant of the game, i.e., an initial state can be transformed into a final state if and only if the values of the invariant of both states agree. We also investigate certain states with particularly interesting properties. Apart from the classical version of the game, we propose several variants, in particular a version with more than only two states (light on, light off), where the analysis relies on systems of linear equations over the ring mathbb{Z}_{n}. Although it is easy to find a concrete solution of the Lights Out problem, we show that it is NP-hard to find a minimal solution. We also propose electric circuit diagrams to actually realize the Lights Out game.

Approximation of Torricelli's law with Euler's method and an instrumented water tank with ultrasonic sensor

In this work, the development of a computer system that has as processing core, an Arduino Nano based board, that collects and processes the signals of a low-cost ultrasonic sensor is presented. The computer system allows monitoring the evolution over time of the height of the water into a container once it begins to empty through a hole in the bottom of it, thus revisiting Torricelli's law with a technological approach using a instrumented container by a computerized electronic data capture and processing data system. The work presents the electrical connection diagrams to interconnect the microcontroller based board and the ultrasonic sensor, as well as the source code used during data acquisition and processing. A comparison of the experimental results is made with results obtained when using the particular analytical solution for the problem, also with the results obtained from implementing the Euler method in obtaining an approximate numerical solution. The presented computer system can be modified and adapted for various academic, educational and research purposes in the various fields of computer engineering, computer systems and mechatronics.

Lattice Monte Carlo study of orientational order in a confined system of biaxial particles: Effect of an external electric field.

In this work we have used lattice Monte Carlo to determine the orientational order of a system of biaxial particles confined between two walls inducing perfect order and subjected to an electric field perpendicular to the walls. The particles are set to interact with their nearest neighbors through a biaxial version of the Lebwohl-Lasher potential. A particular set of values for the molecular reduced polarizabilities defining the potential used was considered; the Metropolis sampling algorithm was used in the Monte Carlo simulations. The relevant order parameters were determined in the middle plane of the sample and for some cases across the whole thickness of the sample. We have determined the temperature-electric field phase diagram for this system and found, as expected, five different system configurations corresponding to three different mesophases. At low temperatures and low fields the system finds itself in an undistorted biaxial phase. On increasing the field at low temperatures, a Freedericksz transition takes place and the secondary directors reorient towards the field while the primary director stays undistorted and parallel to the walls. On increasing the field further, a second Freedericksz transition occurs and the primary director orients also towards the field direction. The orientational order measured at the field strengths tested is not affected by the field. On increasing the temperature, a transition to a uniaxial phase occurs and within the range of this phase a field increase leads also to a Freedericksz transition where the main director reorients towards the field. At higher temperature a transition to a disordered phase is found. We have performed finite size scaling analysis for the Freedericksz critical fields and found that they scale with the distance L between the walls as L^{-1} as expected from continuum theory. From these fields we have also determined the temperature dependence of two elastic constant ratios. Critical exponents and critical temperatures for the order parameter and the correlation length for the biaxial-uniaxial phase transition and the uniaxial to disordered phase transition were also determined by finite size scaling and are discussed.

Electric field distribution of Ag@CuO and Ag@ZnO core–shell dimer

The effect of shape, material and shell thickness on electric field distribution of both Ag@CuO and Ag@ZnO core–shell dimer is investigated. First, three core–shell structures, including plane@circle, triangle@circle and quadrilateral@circle are designed. The field enhancement advantages of the quadrilateral@circle structures are summarized by analyzing the electric field distribution diagrams. Then the influence of materials on the field enhancement effect of core–shell dimer is discussed. The results show that Ag@CuO structure has better stability, while Ag@ZnO structure have larger electric field enhancement. Finally, the shell thickness is changed from 0.1 nm to 1.5 nm. We found that the X-component electric field of both the Ag@ZnO and Ag@CuO core–shell dimer structure is decreased with the increase in the shell thickness. Also, the X-component electric field of Ag@ZnO core–shell dimer is about five times than that of the Ag@CuO. The increase of electric field indicated that Ag@ZnO core–shell dimer has strong local surface plasma resonance characteristics.

DESFĂȘURAREA VIRTUALĂ A LUCRĂRILOR DE LABORATOR DE MAȘINI ELECTRICE ÎN MEDIUL DE CALCUL MATLAB -SIMULINK

"The paper presents the author's experience in supporting laboratory applications in the Electrical Machines course during the pandemic caused by the SARS-CoV-2 virus, when teaching hours were conducted online, like activities specific to the distance learning. The experiments in the laboratory works are simulated in the MATLAB-Simulink computing environment by using and adapting the existing transformer and electrical machine models in the SimPowerSystem library. The design of numerical applications was made so that the implementation of electrical diagrams is performed by students, given that they have no experience in numerical modeling of electrical machines. Several methods for obtaining the results from numerical experiments are presented, which allow to ensure a balance between the number of data specific to each experiment and the calculation effort required, so that the experiments can be performed in the time allotted to a laboratory work. Paper purpose: Description of practical teaching aspects related to the simulation classical tests of the electrical machines in MATLAB- Simulink, in order to virtualize the laboratory works and to adapt them to on-line distance learning. Elements of originality: 1. Developing models for adjustable circuit elements and instrumentation required for simulation testing of electrical machines in steady-state regime. 2. Development of the more accurate DC electric machines model that considers the magnetic circuit hysteresis. 3. Analysis of the methods of using the simulation schemes for obtaining in a reasonable time the data that allow the representation of the operating characteristics."

Temperature and Electric Field Dependent Phase Transformations in [001] PMN-PT Single Crystal

The capacitance of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) [001]-oriented single crystal was examined as a function of temperature and applied external dc electric field. The phase transition temperatures under the applied electric field were measured upon cooling the crystal (zero-field heating field-cooling condition) from paraelectric cubic phase. From these data, temperature versus electric field phase diagram of PMN-xPT crystal have been constructed and discussed.

Experimental investigation of a CPVT collector coupled with a wedge PVT receiver

This paper presents an experimental investigation of a photovoltaic-thermal solar collector (commonly known as PVT) that generates both electricity and heat from the same gross area. PVT solar collectors, in theory, achieve higher combined electrical and heat yields. Additionally, PVT enables a thermal coupling between PV cells and a heat transfer cooling medium. Electrical and thermal outdoor testing measurements have been performed on a low concentration PVT solar collector based on a parabolic reflector geometry with a wedge PVT receiver. Several outdoor experiments have been carried out and presented, such as daily instantaneous electrical and thermal performance efficiency diagrams, as well as optical efficiency charts. Moreover, an electrical Incidence Angle Modifier (for both transversal and longitudinal directions) assessment has been performed and presented. Furthermore, an overall heat loss coefficient of 4.1 W/m2.°C has been attained. A measured thermal optical and electrical efficiency of 59% and 8% have been achieved, respectively. Additionally, the placement of the wedge receiver shown to be very sensitive to high incidence angles, as the electrical transversal Incidence Angle Modifier factor decreases significantly after reaching its electrical peak efficiency at 10°.

A Double-Phase High-Frequency Traveling Magnetic Field Developed for Contactless Stirring of Low-Conducting Liquid Materials

The use of low electrically conducting liquids is more and more widespread. This is the case for molten glass, salt or slag processing, ionic liquids used in biotechnology, batteries in energy storage and metallurgy. The present paper deals with the design of a new electromagnetic induction device that can heat and stir low electrically-conducting liquids. It consists of a resistance-capacity-inductance circuit coupled with a low-conducting liquid load. The device is supplied by a unique electric power source delivering a single-phase high frequency electric current. The main working principle of the circuit is based on a double oscillating circuit inductor connected to the solid-state transistor generator. This technique, which yields a set of coupled oscillating circuits, consists of coupling a forced phase and an induced phase, neglecting the influence of the electric parameters of the loading part (i.e., the low-conductivity liquid). It is shown that such an inductor is capable to provide a two-phase AC traveling magnetic field at high frequency. To better understand the working principle, the present work improves a previous existing simplified theory by taking into account a complex electrical equivalent diagram due to the different mutual couplings between the two inductors and the two corresponding induced current sets. A more detailed theoretical model is provided, and the key and sensitive elements are elaborated. Based on this theory, equipment is designed to provide a stirring effect on sodium chloride-salted water at 40 S/m. It is shown that such a device fed by several hundred kiloHertz electric currents is able to mimic a linear motor. A set of optimized operating parameters are proposed to guide the experiment. A pure electromagnetic numerical model is presented. Numerical modelling of the load is performed in order to assess the efficiency of the stirrer with a salt water load. Such a device can generate a significant liquid motion with both controlled flow patterns and adjustable amplitude. Based on the magnetohydrodynamic theory, numerical modeling of the salt water flow generated by the stirrer confirms its feasibility.

ОСОБЕННОСТИ ТОКОРАСПРЕДЕЛЕНИЯ В ТЯГОВОЙ РЕЛЬСОВОЙ СЕТИ ПРИ ТЯЖЕЛОВЕСНОМ ДВИЖЕНИИ

The paper investigates the limits of change in resistance value of traction rail network elements due to dynamic loads arising during the movement of trains with increased weight and length. An augmented electric diagram of rail joint with a duplicating junction coupler taken into account has been presented. The ways of traction current flow during simultaneous passing of heavy-weight trains along the adjacent track connected by intertrack junctions have been determined. Conclusions have been made about the necessity of constant monitoring of traction rail network elements condition, which can be ensured only by implementing special automated systems.

Разработка базового источника напряжения для микросети на возобновляемых источниках энергии

At the heart of a micro-grid that includes several sources of electrical energy, including renewable energy, there must be a base (reference) source that sets the voltage and frequency in the network. (Research purpose) The research purpose is in developing a basic voltage source of a micro-grid, which includes renewable energy sources. (Materials and methods) The article shows that the sources of electrical energy are different, but the main requirement for them is to be able to supply voltage to the electrical network at any time, there is a standard voltage scale in the network. For a micro-grid, which will include various sources of electrical energy with a total power of up to 25 kW, you can limit yourself to a voltage of 220 V and a single-phase electrical network. (Results and discussion) The article presents a block diagram; technical characteristics and electrical diagram of the inverter of a single-phase basic voltage source; a method for calculating the output filter of the inverter based on pulse-width modulation technology. (Conclusions) When using renewable energy sources in the micro-grid, it is necessary to take into account that there are periods of time in which they do not generate electrical energy and choose as the base one that will not have such moments, or you need to use a temporary electricity storage device. It is possible to use a chemical source or a battery of accumulators as a base source. When creating a micro-grid of alternating voltage, an inverter is added to these sources from constant voltage to alternating voltage. The article presents a block diagram of a base voltage source with an AC output reference voltage to create a micro grid with a power of up to 25 kW.

Modeling the Operating Modes of a Photovoltaic System

During the operation of photovoltaic installations, the inconstancy of the energy characteristics of the flow of incident solar radiation adversely affects the generation of electrical energy. Consumers are highly dependent on climatic factors and solar insolation. For more efficient operation of generating solar installations, it is necessary to conduct detailed studies of the characteristics of the auxiliary and control equipment of the photovoltaic system. When using mathematical programs to simulate the operating modes of solar power generating systems, it is possible to significantly improve the operating parameters of control units and auxiliary systems and increase the generation of electrical energy. The paper presents an improved electrical diagram of a photovoltaic generating system, its control elements, and the efficiency of energy generation is increased. It also describes a method for modeling the operating modes of photovoltaic (PV) modules, implemented in the Matlab/Simulink program. In the work, it was necessary to define a circuit simulation model for the solar array to ensure interaction with the power converter. The characteristics of the solar cells, which are influenced by irradiation and temperature, are modeled by a circuit model. A simplified equivalent circuit for a diode equivalent PV system is used as a model. The simulation results are compared with different types of PV module data. As a result of the work, it was shown that the created simulation blocks in the Matlab/Simulin system well simulate the operation of solar panels, while they are compatible with different types of photovoltaic modules and are convenient in providing various operating modes. In the study of real operating modes of the proposed generating system, the possibility of increasing the generation of electrical energy was shown. When using the proposed circuit solutions for the operation of solar installations, it is possible to significantly increase their efficiency, extend the trouble-free operation, and increase the service life of the equipment. The conducted research contributes to a better use of blocks of photovoltaic systems used to provide electrical energy to industrial, municipal and individual consumers. The circuit solutions proposed in the work are possible for use both at large solar power plants operating in parallel with the general energy system, and at small photovoltaic installations used to provide individual consumers.

Analysis of Processes Mechanized Oil Mining with the Methods Theory of Electrical Circuits

The authors investigate the problems of the development of the oil and gas complex at the last stage of operation, when oil is extracted by lifting. The main methods of lifting employed in the Russian Federation and the USA are described. A particular focus is placed on large water cuts at this stage of oil production. Literature on the issue under investigation is reviewed and the problem is set to analyze and construct models of oil production processes at the stage of well operation by lifting methods using network analysis (electrical circuits) in order to rationally manage all processes comprehensively. A typical flow chart of the oil production process by lifting methods is described. Technological processes of oil production are compared to processes in electric circuits. Thus the process of pumping purified formation water into injection wells by means of block cluster pumping units is similar to the process of recharging a battery using an electric power generator. The process of filling a production well with gas-liquid mixture displaced from the formation under pressure of injection wells is similar to the process of charging a capacitor from a battery, the process of lifting liquid from production wells using production pumps — to the process of discharging a capacitor on an active load. The simplified electrical diagram of a typical flow chart of oil production processes at this stage is given. Based on the given equivalent electrical circuit of technological processes, according to the laws of theoretical electrical engineering, models of the battery charging, capacitor charging and discharging processes are built. The table of correspondence of the parameters of technological and electrical circuits is presented on the basis of which the authors propose simplified models of the processes of pumping purified formation water into injection wells using unit cluster pumping stations, of filling a production well under pressure of the injection well, lifting liquid from production wells by means of suction pumps and conditions under which various operating modes of lifting processes are achieved.

ИССЛЕДОВАНИЕ ЭФФЕКТИВНОСТИ ОЗОНИРОВАНИЯ КУРИНЫХ ЯИЦ

The production of chicken eggs in the world, without slowing down, has passed for 1 trillion pieces. In conditions of saturation and oversaturation of many local markets, food eggs are transported to other remote regions or stored in warehouses, store shelves, losing their freshness and nutritional quality. The ozone can be used to disinfect the surface of chicken eggs, which suppresses microorganisms. Based on the disinfection and disinsection properties of ozone, it is proposed to treat chicken eggs with ozonated air after sorting them by opto-electronic method. (Research purpose) The research purpose is in developing a method for surface disinfection and optoelectronic sorting of food and refrigerator chicken eggs, studying the effectiveness of the performed operations in comparison with traditional methods. (Materials and methods) Authors studied the efficiency of the optoelectronic system for sorting and electrozoning chicken eggs on the basis of a laboratory installation in the Kuban State Agrarian University. The reliability of the results is confirmed by a multiply repetition of research and reproducibility of the data, the use of generally accepted methods, instruments, and mathematical processing of experimental data. (Results and discussion) The article presents an experimental study to determine the effectiveness of electrozoning of chicken eggs in comparison with traditional methods. The article describes rational parameters and modes of operation of the optoelectronic installation for monitoring chicken egg shells. (Conclusions) The article presents an analytical description of the ratio of the main parameters of an optoelectronic installation for monitoring chicken egg shells. The article presents a basic electrical diagram for studying the parameters and operating modes of the installation. The greatest efficiency of electrosonation of chicken eggs is achieved when the ozone concentration is of 1000 milligrams per cubic meter and the ozonation time is 30 minutes; up to 99 percent of harmful microorganisms and viruses on the shell are eliminated.

Compatibility of household appliances with DC microgrid for PV systems

DC distribution of PV systems has spread back especially in the residential sector as a variety of electronic appliances became locally available in the market. The compatibility of household appliances with the best voltage-level in a DC environment is the field that still in the research phase and has not yet made a practically extensive appearance. This paper mainly discusses this issue by providing a review of the concerning research efforts, identifying the gaps in the existing knowledge. The work explains the electrical diagrams of the recently produced appliances, classifying them to get an understanding of how each one consumes energy. It includes exploiting the recent dependence of the commercial appliances on power electronics to improve the efficiency of the existing DC distribution systems by extrapolating new architectures. The proposed topology has a DC distribution environment with two levels of voltage for all appliances. Appliances performances have been evaluated by calculating the energy transfer efficiency. The outcomes of this work can help in designing more efficient DC power distribution networks with minimal energy converters and establishing standardizations for DC microgrids.

Diagnostic Devices for Remote Controller of Synchronous Machines

In this paper, the prerequisites of creating a device for diagnosing the breakdown of the rectifier diodes and discharge thyristor of the brushless exciter of the synchronous machine without the need for its disassembly are considered. The processes occurring in the exciter and its rotating rectifier are analyzed. Requirements for the system of diagnosis of the exciter are formulated. The results of laboratory experiments performed are shown, the possibility of providing diagnostics (detection of breakdown) of rotary elements of the exciter (diodes, discharging thyristors) before starting the machine by applying a 220 V 50 Hz voltage to the exciter’ excitation winding are shown. It is shown that the damage of the exciter elements located on the rotor can be detected by analyzing the EMF of the excitation winding of the exciter, for which it must be powered from a source with high output resistance (a gyrator with the active elements was used in the experiment). An electrical circuit diagram of a system for diagnosing the elements of the exciter located on the rotor, which is made on the basis of a single-crystal microcontroller and allows to detect the breakdown of the diodes of the rotary rectifier or the discharge circuit on the stopped machine (before starting). In addition, during machine startup, the proposed system captures the firing voltage of the discharge circuit, and during operation – measures the voltage at the output of the rotary rectifier. The data transmission from the exciter rotor, on which the proposed system is installed, is carried out by the use of an air transformer by the method of back-scattering

Large electrostrain in Bi1/2Na1/2TiO3-based relaxor ferroelectrics: A case study of Bi1/2Na1/2TiO3-Bi1/2K1/2TiO3-Bi(Ni2/3Nb1/3)O3 ceramics

(1-x)(0.8Bi1/2Na1/2TiO3-0.2Bi1/2K1/2TiO3)-xBi(Ni2/3Nb1/3)O3 (BNKT-xBNN) solid solution ceramics were fabricated by high temperature solid-state reaction method. All the compositions possess relaxor ferroelectric features, among which the ergodic BNKT-0.02BNN exhibits large repeatable electrostrain value Suni = 0.51% at electric field of 65 kV/cm, with high piezoelectric stain coefficient d33∗ of 890 pm/V at 45 kV/cm, while the non-ergodic compositions present unrepeatable large strain response. Based on the electric field-composition phase diagram, the repeatability of strain response in ergodic compositions can be attributed to the reversible electric-field-induced phase transition. In addition, the effects of BNN contents on the macroscopic strain properties are explored by analyzing the existing states of the polar regions with corresponding thermal evolutions and electric-field-induced phase transitions. This research is expected to guide the design of lead free relaxor ferroelectric materials with desired electrostrain properties.