Кафедра "Електричні апарати"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/43

Офіційний сайт кафедри http://web.kpi.kharkov.ua/ea

Кафедра "Електричні апарати" була створена в 1931 році при Харківському електротехнічному інституті. Засновником, організатором і першим завідувачем кафедри був видатний фахівець в галузі електротехніки професор Вашура Борис Федорович.

Кафедра входить до складу Навчально-наукового інституту енергетики, електроніки та електромеханіки Національного технічного університету "Харківський політехнічний інститут", веде підготовку фахівців що мають глибокі знання з електромеханіки та різнобічні знання в області комп’ютерної техніки й інформаційних технологій.

У складі науково-педагогічного колективу кафедри працюють: 2 доктора технічних наук, 6 кандидатів технічних наук, 1 кандидат фізико-математичних наук; 5 співробітників мають звання доцента, 1 – старшого наукового співробітника.

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Зараз показуємо 1 - 20 з 1809

3D-моделирование для определения осевых сил, действующих на элементы торцевой зоны мощного турбогенератора
(НТУ "ХПИ", 2013) Гайденко, Юрий Антонович; Вишневский, Тарас Станиславович; Штогрин, Александр Валерьевич
Разработана полевая математическая модель торцевой зоны мощного турбогенератора типа ТВВ-1000-2У3 в трехмерной постановке. Выполнено моделирование номинального режима работы турбогенератора. Проведён анализ распределения элетромагнитного поля, вихревых токов, а также силы Ампера, возникающей в таких элементах торцевой зоны турбогенератора, как нажимная плита, нажимные пальцы и электропроводящий экран.
A refined mathematical model of physical processes in a conductor at a high-current pulse discharge
(Харківський національний університет міського господарства імені О. М. Бекетова, 2021) Bajda, Yevgen I.; Pantelyat, Michael G.
A novel mathematical model describing physical processes during the flow of an aperiodic pulse current with amplitude of 100 kA along a conductor with a circular cross-section is proposed and investigated. It is shown how a short-term electric discharge of an aperiodic shape affects the distribution of the current density in the cross-section of the conductor, causing its nonuniform heating and the appearance of significant thermal forces as well as mechanical stresses and strains. Based on the developed mathematical model, the relationship between electromagnetic, thermal and mechanical phenomena is shown, allowing a deeper understanding of the multiphysics processes taking place. The maximum values of the current density are calculated, which on the surface of the conductor reach values of 47 kA/mm2, while the temperature rise of a copper conductor with a diameter of 2.44 mm is no more than 80ºC at high temperature gradients, which causes the appearance of thermal stresses that have value (40–50)% of the value of the short-term strength limit of electrical copper. Utilization of this model allows to more accurately determine the required conductor cross-section based on the characteristics of electromagnetic, thermal and mechanical processes. It is shown that the simplified model (the condition for the uniform distribution of the current over the cross-section) gives significantly underestimated values of temperatures and does not take into account temperature deformations.
Active shielding of magnetic field with circular space-time characteristic
(Національний технічний університет "Харківський політехнічний інститут", 2020) Kuznetsov, B. I.; Nikitina, T. B.; Bovdui, I. V.; Petrov, S. V.; Kolomiets, V. V.; Kobilyanskiy, B. B.
Aim. The synthesis of two degree of freedom robust two circuit system of active shielding of magnetic field with circular spacetime characteristic, generated by overhead power lines with "triangle" type of phase conductors arrangements for reducing the magnetic flux density to the sanitary standards level and to reducing the sensitivity of the system to plant parameters uncertainty. Methodology. The synthesis is based on the multi-criteria game decision, in which the payoff vector is calculated on the basis of the Maxwell equations quasi-stationary approximation solutions. The game decision is based on the stochastic particles multiswarm optimization algorithms. The initial parameters for the synthesis by system of active shielding are the location of the overhead power lines with respect to the shielding space, geometry and number of shielding coils, operating currents, as well as the size of the shielding space and magnetic flux density normative value, which should be achieved as a result of shielding. The objective of the synthesis is to determine their number, configuration, spatial arrangementand and shielding coils currents, setting algorithm of the control systems as well as the resulting of the magnetic flux density value at the shielding space. Results. Computer simulation and field experimental research results of two degree of freedom robust two circuit system of active shielding of magnetic field, generated by overhead power lines with «triangle» type of phase conductors arrangements are given. The possibility of initial magnetic flux density level reducing and system sensitivity reducing to the plant parameters uncertainty is shown. Originality. For the first time the synthesis, theoretical and experimental research of two degree of freedom robust two -circuit t system of active shielding of magnetic field generated by single-circuit overhead power line with phase conductors triangular arrangements carried out. Practical value. Practical recommendations from the point of view of the practical implementation on reasonable choice of the spatial arrangement of two shielding coils of robust two -circuit system of active shielding of the magnetic field with circular space-time characteristic generated by single-circuit overhead power line with phase conductors triangular arrangements are given.
An adaptive harmonic compensation strategy for three-phase shunt active power filter based on double second-order generalized integrator with prefilter
(Національний технічний університет "Харківський політехнічний інститут", 2020) Kalkoul, Sami; Benalla, Hocine; Nabti, Khalil; Abdellatif, Reama
This study presents a straightforward adaptive prefiltering algorithm based on a double second-order generalized integrator with prefilter to solve one of the power quality issues, this algorithm is in charge of the determination of the reference harmonic currents in the control of three-phase shunt active power filter which presents an effective way to enhance the grid current quality. The proposed algorithm is used twice, to extract the harmonic currents produced by the non-linear loads and be an interesting part in the estimation of the frequency and amplitude of the fundamental voltage in various anomalies which can be noticed on the grid voltage. The performance, precision, and robustness of the proposed method are evidenced under balanced, unbalanced, and distorted grid voltage in the simulation and experimental results obtained by the implementation of the shunt active power filter on MATLAB-Simulink environment and the dSPACE 1104 platform respectively.
Adaptive maximum power point tracking using neural networks for a photovoltaic systems according grid
(Національний технічний університет "Харківський політехнічний інститут", 2021) Sahraoui, Hamza; Mellah, Hacene; Drid, Said; Chrifi-Alaoui, Larbi
This article deals with the optimization of the energy conversion ofa grid-connected photovoltaic system. The novelty is to develop an intelligent maximum power point tracking technique using artificial neural network algorithms. Purpose. Intelligent maximum power point tracking technique is developed in order to improve the photovoltaic system performances under the variations of the temperature and irradiation. Methods. This work is to calculate and follow the maximum power point for a photovoltaic system operating according to the artificial intelligence mechanism is and the latter is used an adaptive modified perturbation and observation maximum power point tracking algorithm based on function sign to generate an specify duty cycle applied to DC-DC converter, where we use the feed forward artificial neural network type trained by Levenberg-Marquardt backpropagation. Results. The photovoltaic system that we chose to simulate and apply this intelligent technique on it is a standalone photovoltaic system. According to the results obtained from simulation of the photovoltaic system using adaptive modified perturbation and observation – artificial neural network the efficiency and the quality of the production of energy from photovoltaic is increased. Practical value. The proposed algorithm is validated by a dSPACE DS1104 for different operating conditions. All practice results confirm the effectiveness of our proposed algorithm.
Advanced research of the impact of rotor bars anisotropic conductivity on starting torque of an induction motor with a die-cast copper cage
(НТУ "ХПИ", 2006) Chuvashev, V. A.; Varenyk, Ye. A.; Papazov, Yu. A.; Chuvankov, V. Yu.; Zheleznyakov, A. V.
The paper deals with an optimal design of an induction motor with a die-cast copper cage rotor characterized by an anisotropic layer in the upper part of the rotor bars. 1D FEM optimization of an explosion-proof induction motor with a die-cast copper rotor with overall parameters of a commercial induction motor with a die-cast aluminum rotor (180 kW, 1140 V, 1500 rpm) is made with the help of numeric computations. In the paper, the design features and experimental results are given. It is shown that induction motors with a special "starting" layer placed in the upper part the diecast copper rotor bar have maximum value of starting torque for relative conductivity factors ranging from 0.3 to 0.5. The basic performance data obtained in both bench and service tests of a prototype 210kW induction motor are in close agreement with analytical data.
Air cavity-based vibrational piezoelectric energy harvesters
(Національний технічний університет "Харківський політехнічний інститут", 2021) Mohamad Yusoff, Ahmad Azrul; Ahmad, Khairul Azman; Sulaiman, Siti Noraini; Hussain, Zakaria; Abdullah, Noramalina
Known vibrational energy harvesting methods use a source of vibration to harvest electric energy. Piezoelectric material works as a sensing element converted mechanical energy (vibration) to electrical energy (electric field). The existing piezoelectric energy harvesting (PEHs) devices have low sensitivity, low energy conversion, and low bandwidth. The novelty of the proposed work consists of the design of PEH’s structure. Air cavity was implemented in the design where it is located under the sensing membrane to improve sensitivity. Another novelty is also consisting in the design structure where the flexural membrane was located at the top of electrodes. The third novelty is a new design structure of printed circuit board (PCB). The purpose of improvised design is to increase the stress in between the edges of PEH and increase energy conversion. With the new structure of PCB, it will work as a substrate that absorbs surrounding vibration energy and transfers it to sensing element. Methods. Three techniques were successfully designed in PEH and fabricated namely PEH A, PEH B, and PEH C were characterized by two experiments: load and vibration. The load experiment measured load pressure towards the PEH, whereas the vibration experiment measured stress towards the PEH. Results. PEH C has the highest induced voltage for a weight of 5.2 kg at the frequency of 50 Hz and the highest stored voltage for a period of 4 min. The three techniques applied in PEHs were showed improvement in transducer sensitivity and energy conversion. Practical value. A piezoelectric acoustic generator was used in the experiment to compare the performance of the designed PEH with available piezoelectric transducers in the market. The new flexible membrane worked as a sensing element was worked as a cantilever beam. PVDF was used as a sensing element due to the flexibility of the polymer material, which is expected to improve sensitivity and operating bandwidth.
Ameliorate direct power control of standalone wind energy generation system based on permanent magnet synchronous generator by using fuzzy logic control
(Національний технічний університет "Харківський політехнічний інститут", 2020) Lebied, Rima; Lalalou, Rachid; Benalla, Hocine; Nebti, Khalil; Boukhechem, Ismail
Electricity is a basic energy for life and its consumption increased so we need the discovery of new sources of energy such as wind energy .for thisameliorate the quality of generated wind energyby using the intelligent artificial control, this control is made to optimize the performance of three-phase PWM rectifier working.
Analysis and verification of the operation of the stabilizing robust controller's electrical circuit of the rotor flux-linkage control system
(Національний технічний університет "Харківський політехнічний інститут", 2020) Khlopenko, I. N.; Khlopenko, N. J.; Rozhkov, S. A.
On the basis of the classical theory of robust control, the theory of stability and the theory of continued fractions, the linearized mathematical model, the procedure for calculating and designing an analog electrical circuit of the H∞-suboptimal robust controller of the flux-linkage control system of the rotor of an asynchronouselectric drive, protected by Ukrainian Patent no.137157, were built. The circuit contains three operational amplifiers, several resistors and capacitors. The proposed mathematical model, the procedure for calculating and choosing the parameters of the resistors and capacitors of the circuit take into account the random variations of the object and the controller within the specified boundaries. An analytical relationship between the transfer function coefficients and the resistances of the resistors and the capacitances of the capacitors of the controller's electrical circuit was established. On a specific example, by calculation according to the developed algorithm, the limiting values of the tolerances of the circuit's resistances of the resistors and capacitances of the capacitors were identified and these values were selected with a margin from the standard series. Analysis of noise filtering by the electrical circuit of the controller in the Multisim package shows its insensitivity to noise spreads within fairly wide boundaries.
Analysis of electromagnetic processes in the system "cylindrical solenoid - massive conductor"
(НТУ "ХПИ", 2018) Batygin, Yu. V.; Chaplygin, E. A.; Sabokar, O. S.; Strelnikova, V. A.
Defining the key parameters of the inductor geometry, as a long multi-turn solenoid, that influence on the current amplitude induced excited in a massive conductor with a flat boundary surface. Performing a mathematical analysis of the electrodynamic problem solution for an area with variable structure by integrating Maxwell's equation within the given boundary and initial conditions and also physical assumptions simplifying the process of solving but not distorting the result and carrying out an experiment that confirms not only the correctly construction considered but also the acceptability of the chosen assumption the opacity applying of the metal blank for these operating fields frequencies. Functional dependencies of the current induced parameters on the metal surface of the heating object have been obtained, along which numerical estimates of the electrodynamic process have been performed, and key parameters influencing the heating efficiency have been determined. The correctness of the solutions obtained was confirmed experimentally. The final form of the solution function of the physical-mathematical problem was shown to be acceptable for performing further engineering and research calculations. The functional connection of the measured values of the induced surface current and the parameters of the measuring system is determined, the experimental confirmation of which indicates the satisfactory calculation model of the induction heating system and the entire solution as a whole. Based on the calculations performed, working samples of inductive systems for induction heating that meet the specified heating rate and area requirements can be constructed. The obtained analytical expressions were transformed and simplified for their further using for engineering calculations with a minimum error value.
Analysis of optimization criteria for the process of switch displacement in a DC railroad turnout
(PC Tесhnology сеntеr, 2019) Buriakovskyi, S. G.; Smirnov, V.; Asmolova, L. V.; Obruch, I. V.; Rafalskyi, O.; Maslii, Ar. S.
This paper reports a study into the dynamics of displacing a railroad turnout's switches with a direct start of electric motor and a controlled DC electric drive in the MATLAB environment. The emphasis of simulation was the investigation of processes taking place in the kinematic links of a railroad turnout in the dynamics of its switch displacement. The estimation was based on the optimization criteria for a switch displacement process: the pulse of the impact of a switch against the frame rail, elasticity force in the working rod and a switch turning time. The result of the simulation of a non-controlled electric drive in a railroad turnout of switches has revealed that the values of these parameters are unsatisfactory. Mathematical models of the regulated electric drive for a railroad switch turnout were considered as two-mass electromechanical systems with subordinate regulation of basic coordinates and based on the principle of modal control. The results from mathematical modelling of the switch turning process convince that the numerical values of the optimization criteria for a regulated turning process are improved. Increasing the time of a regulated turning by up to 6 % of direct start results in a decreased impact in the kinematic links. Under the assumption of eliminating a technological gap in the reducer, a decrease in the impact of switches at the turning onset amounts to 6–8 %. At the same time, comparison of impacts at the onset of switch turning, when taking into consideration a technological gap in the reducer, as well as without it, shows a decrease in the elastic force amplitude by 250 %. The impact (a switch momentum pulse) could be reduced by 20–24 % upon turning completion. Our analysis of optimization criteria for the switch displacement process has demonstrated efficiency of the regulated electric drive compared to the direct start of an electric motor. That makes it possible not only to extend the operational functionality of a railroad switch turnout, but also to reduce costs for the current technical inspection, repairs in general, as well as to prolong the inter-repair period.
Analysis of the special features of the thermal process in an induction generator at high saturation of the magnetic system
(НТУ "ХПИ", 2017) Chenchevoi, Vladimir; Romashykhin, Iurii; Romashykhina, Zhanna; Al-Mashakbeh, Atef S.
Development of the method for the assessment of the thermal operation modes of an autonomous electrical power system with an induction motor, aiming at improvement of the reliability of electricity supply and the quality of electric energy. Induction generator mathematical modeling taking into account the magnetic system saturation was used in the research. A heat model taking into account the excess of the temperature of the induction generator units in the mode of high saturation was developed. The obtained results were compared with the experimental data. The paper contains the solution to the problem of improvement of the mathematical models and methods for steel losses determination in there search of the operation modes of an autonomous uncontrolled induction generator taking into consideration the properties of the magnetic system in the mode of high saturation. The expression for determination of steel losses in the mode of high saturation is obtained. It enables the assessment of the induction generator thermal condition. The analytical dependence for the calculation of the steel losses in the mode of magnetic system saturation has been obtained for the first time. The obtained expression for the calculation of the steel losses can be used for determination of the admissible time of generator operation at overload. It will allow avoiding broken winding insulation and complete use of the generator overload capacity. As a result, it will reduce possible irregularities of electricity supply due to the generator preliminary cutoff.
Analysis of the state of the external lightning protection system for operating energy objects
(Національний технічний університет "Харківський політехнічний інститут", 2020) Koliushko, D. G.; Rudenko, S. S.; Kiprych, S. V.
Three stages, which are a basis of analysis of a condition of LPS based on the created algorithm, are considered in detail. An example of the analysis LPS condition of the existing substation with a voltage of 35 kV, created according to the specified method, is given. The program report in 3D form illustrates the unprotected parts of the object. Originality. For the first time, analgorithm for analysis the state of LPS of operating energy facilities according to the IEC 62305 standard has been developed.
Analysis of the strategies for managing extended-range electric vehicle powertrain in the urban driving cycle
(Національний технічний університет "Харківський політехнічний інститут", 2022) Lasocki, Jakub; Krawczyk, Pawel; Kopczyński, Artur; Roszczyk, Pawel; Hajduga, Arkadiusz
An Extended-Range Electric Vehicle (EREV) is a type of electric vehicle that uses an additional internal combustion engine (ICE) to charge the battery in order to provide the vehicle with a greater range than in electric only mode. Purpose. Analysis and comparison of the performance of EREV powertrain managed according to three control strategies: pure electric mode, hybrid mode with ICE constantly working, and hybrid mode with ICE working only at high power demand. Methods. The tests were carried out using a laboratory test stand that represented the structure of EREV powertrain. Liquefied petroleum gas was used as a fuel to supply the ICE. The test conditions were defined by a special driving cycle simulating urban driving. Results. Time series plots of selected parameters of electric motor, electrochemical battery pack, range extender generator and active load system. Practical value. Among the considered control strategies of EREV powertrain, the energy balance of the electrochemical battery is negative for a purely electric mode, significantly positive for continuous range extenders (REXs) operation mode and moderately positive for the mode with REX activation only in dynamic states.
Application of high voltage dividers for power quality indices measurement
(NTU "KhPI", 2017) Anokhin, Y. L.; Brzhezytskyi, V. O.; Haran, Ya. O.; Masliuchenko, I. M.; Protsenko, O. P.; Trotsenko, Ye. O.
Introduction. Determination of power quality indices in high-voltage power grids allows to find the reasons for the deterioration of the power quality. The relevant national and International Standards for power quality contain relevant norms of quality indices and requirements for their accuracy measurement. Problem. The most complicated part in the process of measuring the power quality indices at high voltage is the selection of the corresponding high-voltage scale voltage converters. Therefore, comparing the requirements of IEC 61000-4 30 to high voltage scale voltage converters is an important task. Goal. Analysis of the International Standard IEC 61000-4-30 requirements feasibility for measuring the indices of power quality in high-voltage electrical networks using different types of high-voltage scale voltage converters. Methodology. Comparison of the requirements of IEC 61000-4-30 Standard to high-voltage scale voltage converters, when measuring power quality indices, with the characteristics of high voltage electromagnetic transformers used in Ukraine, and with promising developments of high-voltage converters of other types. Results. It is shown in the study that in order to fulfill some of the requirements for class A of IEC 61000-4-30, the characteristics of electromagnetic voltage transformers should be determined in the substation conditions using mobile calibration high-voltage laboratories. To meet all the requirements for Class A IEC 61000-4-30, it is recommended to use broadband high-voltage dividers of resistive-capacitive type. Originality. In study it is shown firstly that all the requirements of the IEC 61000-4-30 Standard for high-voltage scale voltage converters can be performed on the basis of the use of broadband resistive-capacitive damped voltage dividers. Practical value. Expositions of specific types of resistive-capacitive high-voltage dividers are presented, their parameters are confirmed by the results of state metrological certification.
Application of the computing environment maple to the calculation of the dynamics of the electromagnets in the complicated systems of forced control
(Національний технічний університет "Харківський політехнічний інститут", 2019) Baida, Evgeniy Ivanovich; Clemens, M.; Klymenko, Boris Vladimirovich; Korol, Elena Gennadyevna; Pustovoitov, P. Ye.
The authors propose a technique for calculating the dynamics of electromagnets operating in complex forced systems. Such forced electromagnets are widely used in electromechanical switching devices, in particular in vacuum contactors, to reduce their size, energy consumption and to increase speed, which indicates the relevance of this topic. A mathematical model of the dynamics of a forced electromagnetic system, which takes into account the peculiarities of behavior in transients of its individual elements – the mechanical system, the magnetic and electrical circuits, taking into account the interaction of the electromagnet with a control device when the apparatus is activated, contains certain signs of scientific novelty and is the purpose of the paper. The technique of calculating the dynamics of forced electromagnets uses the computing environment Maple. The calculation is based on a mathematical model, which is a system of nonlinear differentialequations of the magnetic and electric circuits, supplemented by the equations of motion of the elements of a mechanical system. The use of the computing environment Maple, applied here to automatically perform the mathematical transformations, allowsavoiding the complicated processes of choosing the numerical integration method, programming of complex and cumbersome equations and numerical integration procedures, to obtain results of calculations in convenient tabular and/or graphic form. This specifically indicates the practical significanceof this work. The results of the comparison of calculations with previously published experimental data presented in the paper indicate the high efficiencyof the proposed models and techniques.
Application of Vyshnegradky's diagrams for transient analysis in electric discharge installations with stochasticload
(Національний технічний університет "Харківський політехнічний інститут", 2018) Suprunovska, N. I.; Shcherba, M. A.
Purpose. To analyze the transient processes in the discharge circuit of reservoir capacitor of electric discharge installationsat a change in the circuit configuration duringthe discharge as well as to determine the appropriate circuit parameters for which the discharge process described by the third-order differential equation remains a dampedoscillatory process. Methodology. We have applied the concepts of theoretical electrical engineering, the principles of theory of electrical circuits, theory of automatic control systems and mathematical simulation in the software package MathCAD 12. Results. We have obtained the analytical expressions and graphical dependenciesthat allow us to determine a relationship between the value of the element parameters of the discharge circuit of installations with anadditional active-inductive chain and the character ofthe transient discharge process without solving a third-order differential equation. Originality. Using Vyshnegradsky's criteria and their graphical representations in the form of diagrams,we have proposed the procedure for determining the inductance value in additional chain shunting the capacitor of electric discharge installation in order to avoid the undesirable aperiodic discharge transient process in the stochastic load. Practical value. The use of this approach makes it possible to determine the ranges of the expedient change in the additional inductance at different load resistances for the realization of transient process required by the technology – the oscillatory discharge of the reservoir capacitor trough the load.
Approximate method for calculating the magnetic field of 330-750 kV high-voltage power line in maintenance area under voltage
(Національний технічний університет "Харківський політехнічний інститут", 2022) Rozov, V. Yu.; Reutskyi, S. Yu.; Pelevin, D. Ye.; Kundius, K. D.
In order to organize effective protection of working personnel from the action of strong electromagnetic influence when performing work on live high-voltage power lines (HVPL), the existing methods of calculating the magnetic field (MF) need to be developed in the direction of their simplification during operational use. Goal. The purpose of the work is to develop an approximate method and a simplified methodology for calculating the magnetic field flux density near the surface of the 330-750 kV HVPL wires for the prompt determination of the safe distance of the working personnel to the surface of the HVPL wires at the current value of their operating current. Methodology. A new approximate method of calculating the flux density of the MF in the area of work on live HVPL based on the Biot-Savart law and determining the maximum values of the flux density of the MF on the axes of symmetry N of the suspension of N wires, which are decisive for the protection of working personnel, is proposed. Results. Exceeding the maximum acceptable level of the MF for individual power lines at their nominal currents, adopted in the European Union, and the need to implement measures to reduce MF were revealed. Originality. It is shown that the distribution of the 330-750 kV HVPL near N of its split wires with an error of no more than 2.5 % can be determined by the current of only one of the phases of the HVPL. This distribution of MF, which is uneven, is determined by the order of axial symmetry N with the maximum values of the flux density of the MF lying on the axes of symmetry N of the suspension of the phase wires. Practical value. The development of an approximate method and a simplified methodology for calculating the flux density of the MF near the surface of the wires of 330-750 kV HVPL, which allows you to quickly, without the use of a computer, calculate the safe distance to the wires of a specific HVPL at the current value of its operating current, as well as determine the necessary measures for the protection of personnel from the MF, which can be implemented either by physically limiting the minimum distance from the worker's body to the surface of the wires to a dangerous one, or by necessary reduction of the HVPL operating current during repair work. Verification. An experimental verification of the proposed method and methodology was carried out on a laboratory installation with a mock-up of a phase of a 330 kV HVPL from AC 400 type wires at 1500 A current, which confirmed the correctness of the proposed calculation relationships.
Brushless valve electric drive with minimum equipment excess for autonomous floating vehicle
(НТУ "ХПИ", 2017) Volyanskaya, Ya. B.; Volyanskiy, S. M.; Onischenko, O. A.
A simple technical solution for the construction of an automated electric drive with a brushless DC motor is proposed, which excludes the use of intermediate computation of coordinates and an expensive encoder. Practical value. Model of the proposed scheme of an automated electric drive with a minimum hardware redundancy, which confirmed the operability of the proposed solution, were carried out. Analysis of the dynamic and static characteristics of the proposed scheme of an automated asynchronous electric drive with a brushless DC motor with a simplified rotor position sensor has made it possible to determine the maximum speed control range with an allowable level of its pulsations.
Calculation of the equivalent electrical parameters of the inductor of induction channel furnace with defects in its lining
(НТУ "ХПИ", 2018) Podoltsev, O. D.; Zolotaryov, V. M.; Shcherba, M. A.; Belyanin, R. V.
The aim of the paper is to determine a quantitative relationship between measured impedance of the inductor and the electrical characteristics of the separated melt circuit parts for the determination of the place of a liquid metal leakage andfor the improvement in such way the diagnostic system of lining state of induction channel furnaces. The study was performed on the basis of the concepts of theoretical electrical engineering, mathematical physics, and mathematical modeling. Using two equivalent electrical circuits of the inductor the analytical expressions and graphical dependencies, which determine a quantitative relationship between the parameters of the separated parts of a liquid-metal circuit and the impedance of the whole inductor measured in practice, for the presence of different lining defects, were found. The method for calculating the increments of equivalent electrical parameters of the inductor as a function of increments of the parameters of the secondary liquid-metal circuit was proposed. It is proved that for small changes (less than 10 %) of the parameters of the liquid-metal circuit, it is expedient to use a linear relationship between its increments and to create the sensitivity matrix, which clearly shows the presence of a strong or weak interrelation between the disturbed values of the parameters of the secondary circuit and the inductor. The use of this technique allows to develop the database for various types of lining defects for a given furnace and on itsbasis to predict the places of a melt leakage and the state of furnace lining owing to periodical measurements of the inductor parameters.