scholarly journals Development of mathematical models of energy conversion processes in an induction motor supplied from an autonomous induction generator with parametric non-symmetry

2021 ◽  
Vol 4 (8(112)) ◽  
pp. 67-82
Author(s):  
Volodymyr Chenchevoi ◽  
Valeriy Kuznetsov ◽  
Vitaliy Kuznetsov ◽  
Olga Chencheva ◽  
Iurii Zachepa ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Induction Motor ◽  
Output Voltage ◽  
Thermal State ◽  
Operating Conditions ◽  
Induction Generator ◽  
Thermal Transients ◽  
Operating Modes ◽  
Stator Windings

The paper presents studies of the system "induction generator-induction motor" with parametric asymmetry on a mathematical model to determine the quality of generated electricity in load operating modes. A mathematical model of the "induction generator-induction motor" system has been developed taking into account losses in steel and parametric asymmetry. The analysis of the transient characteristics of an induction generator when a motor load is connected in symmetrical and asymmetrical modes of operation is carried out. The results of changes in the main characteristics of an induction motor at various degrees of parametric asymmetry in the generator are presented. The quality of the generated electricity was analyzed based on the calculations of the unbalance coefficients for each of the operating modes. The assessment of the thermal state in steady-state conditions was carried out using an equivalent thermal equivalent circuit. Thermal transients were investigated when starting an induction motor from an autonomous energy source based on an induction generator. On a thermal mathematical model, the study of the effect of the output voltage asymmetry on the heating of the connected induction motor was carried out. It is shown that the asymmetry of the output voltage of an induction generator reaches 3–10 % and causes overheating of the windings in excess of the permissible values. A regression model has been developed for studying the operating conditions of an induction motor when powered by an induction generator with an asymmetry of the stator windings. The use of the obtained equations will make it possible to determine the most rational combination of factors affecting the heating of the stator windings of induction machines, in which they will not overheat above the maximum permissible temperature values of the corresponding insulation classes

scholarly journals THERMAL MODEL OF THE "INDUCTION GENERATOR–INDUCTION MOTOR" SYSTEM WITH NON–SYMMETRY IN THE STATOR WINDINGS

2021 ◽  
Vol 2 (53) ◽  
pp. 47-55
Author(s):  
V. Chenchevoi ◽  
◽  
Iu. Zachepa ◽  
O. Chornyi ◽  
R. Yatsiuk ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Thermal State ◽  
Asynchronous Motor ◽  
Operating Conditions ◽  
Factors Affecting ◽  
Thermal Transients ◽  
Operating Modes ◽  
Stator Windings ◽  
Asynchronous Generator

Purpose. Development of the IG model for estimation of influence of variations of parameters of the generator on quality of process of self–excitation at definition of the basic and boundary operating modes and system of initial excitation at invariable parameters of the generator. Result. The article presents studies of the system "asynchronous generator-asynchronous motor" with parametric asymmetry to determine the quality of generated electricity in load modes of operation on a mathematical model. The assessment of the thermal state in steady-state conditions was carried out using an equivalent thermal equivalent circuit. Thermal transients were investigated when starting an asynchronous electric motor from an autonomous power source based on an asynchronous generator. On a thermal mathematical model, a study of the influence of the asymmetry of the output voltage and its deviation from the nominal value on the heating of the connected asynchronous motor was carried out. A regression model has been developed for studying the operating conditions of electricity consumers when powered by an asynchronous generator with an asymmetry of the stator windings. Practical value. The use of the obtained equations will make it possible to determine the most rational combination of factors affecting the heating of the stator windings of asynchronous machines, at which they will not overheat in excess of the maximum permissible temperature values of the corresponding insulation classes. Figures 9, tables 2, references 23.

scholarly journals Induction Motor Drives Fed by an NPC Inverter with Unbalanced DC-Link

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1379 ◽  
Author(s):  
Umberto Abronzini ◽  
Ciro Attaianese ◽  
Matilde D’Arpino ◽  
Mauro Di Monaco ◽  
Giuseppe Tomasso
Keyword(s):  
Output Voltage ◽  
Harmonic Distortion ◽  
Voltage Regulation ◽  
Motor Drives ◽  
Operating Conditions ◽  
Switching Frequency ◽  
Voltage Level ◽  
Voltage Quality ◽  
Vector Modulation

Neutral Point Clamped (NPC) converters with n levels are traditionally controlled in such a way that the DC-link capacitors operate at 1/( n - 1) of the total DC-link voltage level. The voltage level across the DC-link capacitors has to be properly regulated by the capacitor unbalance control to contain the harmonic distortion of the converter output voltages. State-of-the-art modulation techniques address the problem of the DC-link voltage regulation for NPC inverters. However, they highly show reduced performance when unbalanced DC-link voltages are considered. In this paper, a novel Space Vector Modulation (SVM) is proposed for NPC converters with an unbalanced DC-link. At every modulation interval, the technique defines the optimal switching pattern by considering the actual unbalanced DC-link conditions. The proposed modulation allows improving the harmonic content of the NPC converter output voltage with respect to a traditional ML-SVM, when the same operating conditions are considered. As an extension, the proposed modulation technique will guarantee the same output voltage quality of a traditional ML-SVM with unbalanced DC-link, while improving the conversion efficiency thanks to a reduction of switching frequency.

scholarly journals Optimization of Parameters and Operating Modes of Disc Sowing Device According to Seeding Uniformity Criterion

2018 ◽  
Vol 28 (3) ◽  
pp. 379-388
Author(s):  
Vladimir A. Ovchinnikov ◽  
Mikhail N. Chatkin ◽  
Alena V. Ovchinnikova
Keyword(s):  
Experimental Studies ◽  
Operating Conditions ◽  
Design Parameters ◽  
Optimal Parameters ◽  
Plant Growth And Development ◽  
Important Condition ◽  
Operating Modes ◽  
Favorable Conditions ◽  
Uniformity Criterion

Introduction. When cultivating agricultural crops, it is necessary to take into account the plants’ need for moisture, nutrients, location by area of nutrition, determining illumination, etc. Taking into account the biological characteristics of crops, various methods of sowing are used to create favorable conditions for plant growth and development. An important condition for sowing is the uniform arrangement of seeds along the sulcus, especially in the cultivation of testes of small-seeded cultures. A key role in the uniformity of seeding is provided by the design parameters and kinematic operating conditions of the sowing device. Materials and Methods. To determine the optimal parameters and operating modes of the disk sowing device, methods of factor experiment and multi-criteria optimization were used. Results. Mathematical models of the technological process of sowing seeds were obtained based of experimental studies. Conclusions. To ensure the improvement of the seeding quality of small seeds, the design parameters of the experimental seeder: х4 – is the diameter of the cell; х5 – the number of cells on the disk, will tend to the maximum values. The optimum circumferential speed of the sowing disk should be in the range from 0.127 to 0.192 m/s, and the speed of the machine’s movement is no more than 2 m/s.

Optimization of the Blast Furnace Operating Modes for Identification of the Areas of Unimprovable Solutions

2017 ◽  
Vol 743 ◽  
pp. 363-368 ◽  
Author(s):  
Lev Kazarinov ◽  
Dmitry Shnayder ◽  
Tatyana Barbasova
Keyword(s):  
Blast Furnace ◽  
Coke Consumption ◽  
Thermal State ◽  
Real Life ◽  
Operating Mode ◽  
Optimal Choice ◽  
Operating Modes ◽  
Consumption Reduction ◽  
Reasonable Choice

This work reviews the issues of modeling of the operating modes for a blast furnace and identification of areas of unimprovable solutions on a set of indicators of cast iron output, coke consumption, and thermal state. These areas define the boundaries of potential opportunities for achieving high values of quality of the blast-furnace processes on a set of real-life operating modes of a blast furnace. They also indicate the reserves of coke consumption reduction and output enhancement, which might be implemented by optimal choice of a blast furnace operating mode and which enable the reasonable choice of the operating mode of a blast furnace based on the potential opportunities for increasing the output, minimizing coke consumption for the specified coke quality and the specified requirements to the furnace thermal state.

scholarly journals Dynamic Simulation of High-Speed Induction Motor

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2713
Author(s):  
Maria Dems ◽  
Krzysztof Komeza ◽  
Jacek Szulakowski ◽  
Witold Kubiak
Keyword(s):  
Mathematical Model ◽  
Induction Motor ◽  
High Speed ◽  
Start Up ◽  
Modified Equations ◽  
Higher Power ◽  
The Mathematical Model ◽  
Dynamic Phenomena ◽  
Dynamic States

In the drives of high-speed devices, such as a blood centrifuge, dynamic states also play an important role in terms of the time and quality of the tests performed. The article presents the application of modified equations resulting from the mathematical model of an induction motor to model dynamic phenomena during motor start-up, both with mains supply and with frequency start-up. The applied solution considers the phenomenon of current displacement in the rotor bar and the phenomenon of saturation. The comparison of the obtained results with the experiment shows that the method is sufficiently accurate. The obtained results can also be extended to higher power machines and to modeling other dynamic states.

scholarly journals Influence of transition modes of blast-furnace smelting to change the temperature of the cooling-system plates

2018 ◽  
pp. 3-9
Author(s):  
V.V. Horupakha ◽  
Yu.S. Semenov ◽  
E.I. Schumelchyk ◽  
S.V. Vashchenko ◽  
E.D. Vyshinskaya
Keyword(s):  
Blast Furnace ◽  
Natural Gas ◽  
Thermal State ◽  
Cooling System ◽  
Furnace Operation ◽  
Operating Conditions ◽  
The Body ◽  
Blast Furnace Smelting ◽  
Operating Modes ◽  
Furnace Smelting

Purpose. Estimation of the influence of non-stationary blast-furnace smelting on the thermal state of the cooling system. Methodology. Analysis of changes in the meanings of thermocouples installed in the body of the cooling system plates, under different operating conditions of the blast furnace. Results. The study of the influence of transitional modes of blast-furnace smelting on the temperature change of the cooling-system plates at the joint use of natural gas and coal-pulverized fuel, under conditions of a low-intensity blast furnace operation and using pulverized coal with a consumption of more than 110 kg/ton of pig iron. Findings. The peculiarities of the influence of transitional modes of blast-furnace smelting on the thermal state of the cooling system are established: incl. with various fuel additives for blasting and with the operation of the furnace with reduced intensity. Practical value. The results presented in the article can be used in the design of the cooling system, as well as in the selection of rational operating modes of the blast furnace. Keywords. blast furnace, PCI technology, natural gas, cooling-system plates, thermocouple.

scholarly journals Efficiency increasing by development of district heating systems operational modes using graphical analysis

2019 ◽  
Vol 102 ◽  
pp. 04003
Author(s):  
Vyacheslav V. Tokarev ◽  
Aleksandr V. Alekseev ◽  
Zoya I. Shalaginova
Keyword(s):  
District Heating ◽  
Graphical Analysis ◽  
Operating Conditions ◽  
Heating Systems ◽  
Operating Modes ◽  
Graphical Visualization ◽  
District Heating Systems ◽  
City Plan ◽  
Operational Modes

The tasks of analyzing, developing and justifying of the district heating systems (DHS) operation modes arise at different stages of their life cycle. The article provides a brief description of the tasks, steps and methods for calculating and analyzing DHS modes, which are implementing as subtasks of the "ANGARA-HN" software. Special attention is paying to the automation of analysis processes. The developed computational and graphical software tools for parameters analyzing of the DHS operating modes consists of the means: analyzing of the initial information, calculating the values of the mode parameters and analyzing results of the calculation. Various tools allow you to visualize the distribution of selected parameters values on the graphical city plan, highlight bottlenecks, building pressure distribution graphs. The developed software designed to automate the workplaces of regimes group engineers at operational enterprises or for designer workers, when developing and justifying development schemes for urban DHS. Tools for analysis and graphical visualization significantly increase the efficiency of work by reducing the time of analysis, development and justification of operating conditions, as well as improve the quality of the results.

Analysis of a single-phase capacitor induction motor operating at two power line frequencies

2012 ◽  
Vol 61 (2) ◽  
pp. 251-266 ◽  
Author(s):  
Aleksander Leicht ◽  
Krzysztof Makowski
Keyword(s):  
Mathematical Model ◽  
Induction Motor ◽  
Single Phase ◽  
Induction Motors ◽  
Power Line ◽  
Mathematical Tool ◽  
Simulation Results ◽  
Capacitor Capacitance ◽  
Load Conditions

Analysis of a single-phase capacitor induction motor operating at two power line frequenciesThe paper presents a modelling mathematical tool for prediction of dynamic and steady-states operation of the single-phase capacitor induction motor for different values of the capacitor capacitance and different frequency of voltage supply at no-load and rated load conditions. Developed mathematical model of the capacitor induction motor was implemented for calculation using Matlab/Simulink software. Presented simulation results may be utilized to achieve better starting quality of single-phase capacitor induction motors.

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