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1
Zablodskiy, M. M., V. E. Pliuhin, S. I. Kovalchuk, and V. O. Tietieriev. "Indirect field-oriented control of twin-screw electromechanical hydrolyzer." Electrical Engineering & Electromechanics, no. 1 (February 17, 2022): 3–11. http://dx.doi.org/10.20998/2074-272x.2022.1.01.
Повний текст джерелаАнотація:
Goal. Development of a mathematical model of indirect field-oriented control of a twin-screw electromechanical hydrolyzer. Methodology. The paper presents a mathematical model of Indirect field-oriented control of twin-screw electromechanical hydrolyzer. The mathematical model was developed in the MATLAB / Simulink software environment. The determination of the main parameters of a twin-screw electromechanical hydrolyzer was carried out by developing a finite element model in the Comsol Multiphysics software environment. Results. Based on the results of a mathematical study, graphical dependences of the distribution of magnetic induction in the air gap of a ferromagnetic rotor, a spatial representation of the distribution of magnetic induction on a 3D model of a ferromagnetic rotor of a twin-screw electromechanical hydrolyzer were obtained. The results of finite element modeling were confirmed by a practical study of a mock-up of a ferromagnetic rotor of a twin-screw electromechanical hydrolyzer. By implementing the MATLAB / Simulink model, graphical dependences of the parameters of the ferromagnetic rotor of a twin-screw electromechanical hydrolyzer are obtained under the condition of a stepwise change in the torque and a cyclic change in the angular velocity. Originality. The paper presents an implementation of the method of indirect field-oriented control for controlling the ferromagnetic rotor of a twin-screw electromechanical hydrolyzer. The work takes into account the complex design of the ferromagnetic rotor of a twin-screw electromechanical hydrolyzer. Practical significance. The practical implementation of the results of mathematical modeling makes it possible to achieve effective control of a complex electromechanical system, allows further research to maintain the necessary parameters of the technological process and to develop more complex intelligent control systems in the future.
2
SYTIN, A. V., А. А. KIRICHEK, N. V. TOKMAKOV, and O. V. YAKOVLENKO. "CALCULATION OF FLOOR BEARING WITH FERROMAGNETIC LIQUID OF TURBOGENERATORS OF POWER DISTRIBUTION SYSTEMS." Fundamental and Applied Problems of Engineering and Technology 3 (2021): 153–60. http://dx.doi.org/10.33979/2073-7408-2021-347-3-153-160.
Повний текст джерелаАнотація:
The article discusses ways to solve the problem of wear of the rotor bearings of turbine units at the moments of start–up and shutdown. The concept of a new type of elastic–damping combined sliding bearings, which combines the use of ferromagnetic fluids in the design of multi–blade bearings, is proposed. On the basis of this, a design of a petal bearing with an electromagnetic effect on elastic elements and a ferromagnetic lubricant has been proposed. The properties and features of the use of ferromagnetic fluids in precision engineering as a lubricant are described. A mathematical model of an electromagnetic petal bearing with a ferromagnetic fluid is proposed on the basis of the Reynolds equation from the course of magnetohydrodynamics, Maxwell's equations for a magnetic field, a system of equations in displacements based on the theory of cylindrical shells. An algorithm for the operation of the rotor support during start–up, shutdown, as well as when the power supply of the electromagnets is turned off.
3
Шамин, Евгений, Evgeniy Shamin, Булат Зиганшин, Bulat Ziganshin, Галина Новикова, and Galina Novikova. "DEVELOPMENT OF MICROWAVE DRYERS FOR FUR MATERIALS." Vestnik of Kazan State Agrarian University 12, no. 3 (January 11, 2018): 86–90. http://dx.doi.org/10.12737/article_5a1d9b2ce8e734.23195358.
Повний текст джерелаАнотація:
Abstract. The developed plant belongs to drying equipment and can be used in farms for drying and disinfecting skins of rabbits, nutria, mink, fox, Arctic fox, sable, otter, muskrat, etc. A microwave dryer of a fur raw material of the rotor type comprises a cylindrical shielding element 1, inside of which a cylindrical non-ferromagnetic drum 9 is coaxially disposed, perforated non-ferromagnetic plates are welded to the shell, forming compartments. The drum 9 with the compartments represents the rotor 2, and the compartments serve as the mobile resonators 3. The average perimeter of the annular space between the shielding unit 1 and the drum 9 is equal to a multiple of half the wave length. The rotor 2 rotates from the electric motor 4, installed under the lower base of the shielding uni 1, containing the discharge nozzle 6. The depth of the compartments along the vertical is greater than the width of the bottom base of the trapezoidal radio-transparent rule, and the radial depth of the compartments is greater than the height of the rule. On the upper base of the shielding unit 1, containing the loading branch pipe 7, there are mounted microwave generators 8 and an exhaust fan 10. The branches function as transverse waveguides.
4
Khan, M. R., I. Husain, and M. F. Momen. "Lightly Ferromagnetic Rotor Bars for Three-Phase Squirrel-Cage Induction Machines." IEEE Transactions on Industry Applications 40, no. 6 (November 2004): 1536–40. http://dx.doi.org/10.1109/tia.2004.836226.
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SMIRNOV, Alexsander Yu, Yekaterina N. ALEKSANDROVA, and Andrey Yu ZIMIN. "Refining the Torque Calculation Models in Designing Salient-Pole Inductor Motors." Elektrichestvo 11, no. 11 (2020): 53–59. http://dx.doi.org/10.24160/0013-5380-2020-11-53-59.
Повний текст джерелаАнотація:
The article suggests a procedure for designing salient-pole inductor motors with developed tooth structures on the rotor and stator, which is supplemented by nonlinear calculation of a fragmentary magnetic circuit model with subsequently refining the saturation coefficient. The calculation is carried out using the semigraphical method before and after displacement of the rotor from the position of maximum air gap permeance by half the rotor tooth division with respect to teeth on the stator pole extension. Owing to introducing a weakly branched nonlinear magnetic circuit model into the design algorithm, in became possible to elaborate detail designs of motors for important electric drives of automatic systems, which confirmed their declared characteristics. It is noted that demagnetization of the magnetic circuit ferromagnetic areas, which is determined by calculation on the nonlinear model after turning the rotor by half the tooth division from the coaxial position, is the criterion of the correctly selected tooth area geometric parameters and electromagnetic loads.
6
Iskierka, Sławomir. "Finite element analysis of the performance of a ferromagnetic solid-rotor motor." Finite Elements in Analysis and Design 11, no. 1 (May 1992): 1–8. http://dx.doi.org/10.1016/0168-874x(92)90024-7.
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Jiang, Weilun, Gaopei Pan, Yuzhi Liu, and Zi-Yang Meng. "Solving quantum rotor model with different Monte Carlo techniques." Chinese Physics B 31, no. 4 (April 1, 2022): 040504. http://dx.doi.org/10.1088/1674-1056/ac4f52.
Повний текст джерелаАнотація:
We systematically test the performance of several Monte Carlo update schemes for the (2 + 1)d XY phase transition of quantum rotor model. By comparing the local Metropolis (LM), LM plus over-relaxation (OR), Wolff-cluster (WC), hybrid Monte Carlo (HM), hybrid Monte Carlo with Fourier acceleration (FA) schemes, it is clear that among the five different update schemes, at the quantum critical point, the WC and FA schemes acquire the smallest autocorrelation time and cost the least amount of CPU hours in achieving the same level of relative error, and FA enjoys a further advantage of easily implementable for more complicated interactions such as the long-range ones. These results bestow one with the necessary knowledge of extending the quantum rotor model, which plays the role of ferromagnetic/antiferromagnetic critical bosons or Z 2 topological order, to more realistic and yet challenging models such as Fermi surface Yukawa-coupled to quantum rotor models.
8
Yang, Chao Jun, Dan Lu, You Hu, Xiao Ping Chen, Ru Yu Ma, and Ling Ying Kong. "Magnetic-Field Modulation Principle and Transmission Ratio Calculation of Field-Modulated Asynchronous Magnetic Coupling." Applied Mechanics and Materials 535 (February 2014): 48–52. http://dx.doi.org/10.4028/www.scientific.net/amm.535.48.
Повний текст джерелаАнотація:
A field-modulated asynchronous magnetic coupling is a new type of composite magnetic transmission mechanism, which is based on the principles of magnetic field modulation and electromagnetic induction. The rotational velocity and direction of the inner conductor rotor could be changed, since the magnetic field generated by permanent magnet outer rotor is modulated by ferromagnetic pole-pieces. Therefore, the couplings can meet special conditions with special requirements for load and speed. The formula of the modulated magnetic flux density of inner air gap is analyzed through magnetic field analytic approaches, and then the formula of transmission ratio is also deduced by introducing slip ratio in the mean time. Finally, experimental research of the coupling is conducted. The results show that the transmission ratio of the coupling is not only related to the ratio of the number of pole pairs on outer permanent magnet rotor and the number of pole pairs of magnetic field flux density harmonic, but also related to the slip ratio. Besides, the transmission ratio of the coupling increases non-linearly with the slip ratio.
9
Meyer, Alexander, and Jörg Franke. "Towards an Energy Efficient Series Production of High Performance Permanent Magnet Synchronous Motors by Selective Magnet Assembly." Applied Mechanics and Materials 882 (July 2018): 111–18. http://dx.doi.org/10.4028/www.scientific.net/amm.882.111.
Повний текст джерелаАнотація:
When installing magnets on synchronous rotors, the target values of energy efficiency, vibration, noise emissions, power density and synchronism are decisively influenced by the quality of the rotor magnetic field. This depends on the real position of the magnets after mounting, on the polarization of the magnet and on the direction of magnetisation. However, large component tolerances in the magnet bodies also require tolerances in the rotor magnetic field. The quality assurance in the field of rotor production, which is largely lacking in the current state of the art, is compensated for by robust motor designs in order to keep the rejects low. Unconventional machine designs, such as the Halbach arrangement of the magnets, exploit optimization potential in terms of power density by eliminating the ferromagnetic component in the rotor and reduce harmonics due to the almost sinusoidal field shape, so that more efficient winding processes, such as linear winding in the stator with a constant low torque ripple compared to distributed winding, are used. At the same time, however, the requirement for homogeneity of the magnetic field increases due to the matching pairing of the magnets and the correct magnetic position when using sintered, isotropic rare earth magnets. By 100 % testing of magnets and rotors, it is possible on the one hand to exploit these design potentials and on the other hand to estimate the performance data of the motor before the final assembly test by means of data mining. In the framework of the E|MagTol project, the process feasibility of a logistics solution for storing magnetized goods has already been successfully investigated. In order to extend the potential uncovered in the previous project, it is necessary to record all process data of the rotor assembly process such as magnet geometry, magnet position, polarization and magnetization direction. The aim of E|S2MART is on the one hand to increase machine efficiency by compensating for component deviations by adapting or matching the magnetic position and magnetic parameters in a closed-loop control loop in the assembly process and on the other hand to significantly increase the energy efficiency of the assembly process. This is done by optimizing the magnetization process and coupling with inductive heating to replace the furnace process during the bonding process and to reduce the energy consumption during magnetization. On the basis of the existing process experience, the savings potential in the assembly process is estimated to be at least 70 % compared to conventional processes.
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von Pfingsten, Georg, Martin Marco Nell, and Kay Hameyer. "Hybrid simulation approaches for induction machine calculation." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, no. 5 (September 3, 2018): 1744–54. http://dx.doi.org/10.1108/compel-01-2018-0015.
Повний текст джерелаАнотація:
Purpose Induction machines for traction applications are operated at working points of high ferromagnetic saturation. Depending on the working point, a broad spectrum of harmonic frequencies appears in the magnetic flux density of induction machines. Detailed loss analysis therefore requires local and temporal highly resolved nonlinear field computation. This loss analysis can be performed in the post processing of nonlinear transient finite element simulations of the magnetic circuit. However, it takes a large number of transient simulation time steps to build up the rotor flux of the machine. Design/methodology/approach In this paper, hybrid simulation approaches that couple static FEA, transient FEA and analytic formulations to significantly decrease the number of simulation time steps to calculate the magnetic field in steady state are discussed, analyzed and compared. Findings The proposed hybrid simulation approaches drastically decrease the simulation time by shortening the transient build-up of the rotor flux. Depending on the maximum error of the rotor flux linkage amplitude compared to the steady state value, a reduction of simulation time steps in the range of 55.5 to 98 per cent is found. Originality/value The presented hybrid simulation approaches allow efficient performing of the transient FE magnetic field simulations of induction machines operated as traction drives.
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Tuck, Loughlin E., Claire Samson, Jeremy Laliberté, and Michael Cunningham. "Magnetic interference mapping of four types of unmanned aircraft systems intended for aeromagnetic surveying." Geoscientific Instrumentation, Methods and Data Systems 10, no. 1 (May 19, 2021): 101–12. http://dx.doi.org/10.5194/gi-10-101-2021.
Повний текст джерелаАнотація:
Abstract. Magnetic interference source identification is a critical preparation step for magnetometer-mounted unmanned aircraft systems (UAS) used for high-sensitivity geomagnetic surveying. A magnetic field scanner was built for mapping the low-frequency interference that is produced by a UAS. It was used to compare four types of electric-powered UAS capable of carrying an alkali-vapour magnetometer: (1) a single-motor fixed-wing, (2) a single-rotor helicopter, (3) a quad-rotor helicopter, and (4) a hexa-rotor helicopter. The scanner's error was estimated by calculating the root-mean-square deviation of the background total magnetic intensity over the mapping duration; averaged values ranged between 3.1 and 7.4 nT. Each mapping was performed above the UAS with the motor(s) engaged and with the UAS facing in two orthogonal directions; peak interference intensities ranged between 21.4 and 574.2 nT. For each system, the interference is a combination of both ferromagnetic and electrical current sources. Major sources of interference were identified such as servo(s) and the cables carrying direct current between the motor battery and the electronic speed controller. Magnetic intensity profiles were measured at various motor current draws for each UAS, and a change in intensity was observed for currents as low as 1 A.
12
Lavrinovicha, Ludmila, Roman Dobriyan, and Oskars Onzevs. "Metamodels for Optimum Design of Outer-Rotor Synchronous Reluctance Motor." Electrical, Control and Communication Engineering 5, no. 1 (May 1, 2014): 34–39. http://dx.doi.org/10.2478/ecce-2014-0005.
Повний текст джерелаАнотація:
Abstract A new design of synchronous reluctance motor with segment-shaped outer rotor is presented and investigated in this paper. In order to obtain correct recommendations for optimal design of the studied synchronous reluctance motor, analytical relations of motor electromagnetic parameters and geometrical dimensions (also known as metamodels) have been synthesized. Electromagnetic parameters, which have been used for metamodels synthesis, are obtained by means of magnetostatic field numerical calculations with finite element method using software QuickField. The paper includes the analysis of the studied synchronous reluctance motor geometrical parameters (stator outer diameter, height and overlap angle of rotor’s segment-shaped packages) influence on the electromagnetic torque per unit volume. Testing of synthesized metamodels shows that relative difference between the results obtained by numerical calculations and those obtained with the help of synthesized metamodels does not exceed eight percent at experimental points and intermediate points as well. The proposed optimal design of the segment-shaped outerrotor synchronous reluctance motor obtained with the help of synthesized metamodels has been compared with a salient-pole outer-rotor synchronous reluctance motor having ferromagnetic yoke with the same value of the electromagnetic torque. The comparison results of both motors show that the highest value of electromagnetic torque per unit volume can be achieved with the proposed new design of the synchronous reluctance motor with segment-shaped outer rotor.
13
Ladghem Chikouche, Brahim, and Rachid Ibtiouen. "Analytical approach for spoke-type permanent magnet machine including finite permeability of iron core." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 39, no. 2 (January 22, 2020): 333–52. http://dx.doi.org/10.1108/compel-04-2019-0143.
Повний текст джерелаАнотація:
Purpose The purpose of this study is the introduction of finite permeability of ferromagnetic core in analytical approach for slotted spoke-type permanent magnet machine. Design/methodology/approach A two-dimensional analytical approach of magnetic field distribution is established for spoke-type permanent magnet machine to calculate the flux density distribution in the middle of airgap. The paper presents an analytical subdomain model accounting for stator slotting effect. The governing equations are obtained from Maxwell’s equations by using vector potential in all regions of the machine, i.e. magnet, airgap, stator slots and rotor/stator yoke. The finite element analysis is used to validate the analytical results. Findings It is found that the developed subdomain model including finite permeability of ferromagnetic core is accurate and is applicable for spoke-type permanent magnet machine for no-load and on-load condition. The analytical results are in accurate agreement with the numerical simulation. Originality/value Some assumptions and conditions are presented to improve and simplify the analytical method for analyzing the global saturation for spoke-type permanent magnet machine.
14
ANTIPOV, Victor N., Andrey D. GROZOV, and Anna V. IVANOVA. "Superconducting Wind Generators with Capacities of 10 MW and Larger." Elektrichestvo 10, no. 10 (2020): 59–67. http://dx.doi.org/10.24160/0013-5380-2020-10-59-67.
Повний текст джерелаАнотація:
The overall dimensions and mass of wind power units with capacities larger than 10 MW can be improved and their cost can be decreased by developing and constructing superconducting synchronous generators. The article analyzes foreign conceptual designs of superconducting synchronous generators based on different principles: with the use of high- and low-temperature superconductivity, fully superconducting or only with a superconducting excitation system, and with the use of different materials (MgB2, Bi2223, YBCO). A high cost of superconducting materials is the main factor impeding commercial application of superconducting generators. In view of the state of the art in the technology for manufacturing superconductors and their cost, a conclusion is drawn, according to which a synchronous gearless superconducting wind generator with a capacity of 10 MW with the field winding made of a high-temperature superconducting material (MgB2, Bi-2223 or YBCO) with the «ferromagnetic stator — ferromagnetic rotor» topology, with the stator diameter equal to 7—9 m, and with the number of poles equal to 32—40 has prospects for its practical use in the nearest future.
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Mu, Yaxin, Wupeng Xie, and Xiaojuan Zhang. "The Joint UAV-Borne Magnetic Detection System and Cart-Mounted Time Domain Electromagnetic System for UXO Detection." Remote Sensing 13, no. 12 (June 15, 2021): 2343. http://dx.doi.org/10.3390/rs13122343.
Повний текст джерелаАнотація:
For unexploded O=ordnance (UXO) detection, individual technology cannot achieve the best detection performance. The new detection mode of joint magnetic and electromagnetic method has attracted more and more attention. In this paper, a newly developed joint detection system is introduced, a multi-rotor UAV-based magnetic system (UAVMAG) and a cart-based time-domain electromagnetic detection system (TDEM-Cart) are combined, and the cooperative processing of magnetic field and electromagnetic data is proposed. The result of the joint inversion fuses the feature vector retrieved from the magnetic field data and the feature vector inverted from the electromagnetic data, providing more accurate positioning results and richer information, which is favorable to locate and distinguish the UXO. Two field experiments are conducted, and the results show that when the joint system works in the full-coverage survey mode, both ferromagnetic and non-ferromagnetic metal targets can be detected, avoiding missed detections. In addition, when the joint system works in the cued survey mode, the detection efficiency is improved, the positioning accuracy of joint interpretation is less than 10 cm, and it shows satisfactory performance in the recognition of targets.
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Kuimov, Denis, and Maksim Minkin. "Influence of control algorithms parameters on an electromechanical converter with a secondary discrete part." Serbian Journal of Electrical Engineering 14, no. 3 (2017): 323–31. http://dx.doi.org/10.2298/sjee1703323k.
Повний текст джерелаАнотація:
An alternative configuration of a device with a secondary discrete part using a magnetic system of a similar multi-phase inductor machine and concentrated windings without an internal rotor is proposed. An algorithm of sensorless control of a motion process of a secondary discrete part is proposed. The analysis of the distribution nature of the magnetic field for various switching algorithms is carried out to reduce negative influence of the ?dead? zones of the first and second order. The features of the movement process of the secondary discrete part in the working chamber of the device are considered. The results of in the electromagnetic force change affecting a ferromagnetic working element are presented, and recommendations for the application of switching algorithms are given.
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Torrent, Marcel, and Balduí Blanqué. "Influence of Equivalent Circuit Resistances on Operating Parameters on Three-Phase Induction Motors with Powers up to 50 kW." Energies 14, no. 21 (November 1, 2021): 7130. http://dx.doi.org/10.3390/en14217130.
Повний текст джерелаАнотація:
This work shows the results obtained from studying the influence of equivalent circuit resistances on three-phase induction motors. The stator resistance, rotor resistance, and iron losses resistance affect the different motor operating variables (output power, current, speed, power factor, starting ratios, and maximum torque). These influences have been quantified, paying particular attention to the losses affected and their impact on efficiency. The study carried out does not apply optimization techniques. It evaluates the different influences of the equivalent circuit’s different resistances on its operation by evaluating applicable constructive modifications concerning available motors. The work has been limited to three-phase induction motors up to 50 kW and low voltage, with the nominal powers of the selected motors being 0.25 kW, 1.5 kW, 7.5 kW, 22 kW, and 45 kW. The tools used to carry out the study are analyzing the equivalent circuit and the simulation of the electromagnetic structure using a finite-element program. The variations proposed in each resistance for all the motors studied is not purely theoretical, as it is based on applying feasible constructive modifications, appropriately analyzed and simulated. These modifications are the variation of the conductor diameter in the stator coils, the change of the section of the rotor cage, and the selection of different ferromagnetic steel types.
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Tvorić, Stjepan, Miroslav Petrinić, Ante Elez, and Mario Brčić. "STATIC ECCENTRICITY FAULT DETECTION METHOD FOR ELECTRICAL ROTATING MACHINES BASED ON THE MAGNETIC FIELD ANALYSIS IN THE AIR GAP BY MEASURING COILS." Journal of Energy - Energija 69, no. 4 (December 30, 2020): 3–7. http://dx.doi.org/10.37798/202069451.
Повний текст джерелаАнотація:
Electrical rotating machines have a great economic significance as they enable conversion of energy between mechanical and electrical state. Reliability and operation safety of these machines can be greatly improved by implementation of continuous condition monitoring and supervisory systems. Especially important feature of such systems is the ability of early fault detection. For this reason, several methods for detection and diagnosis of the machine faults have been developed and designed. As fault detection methods can largely differ in the types of detectable faults, machine adoptability and price of the system, a novel method was developed that can be used for cost-effective detection of various faults of electrical machine. Machine fault detection technique presented in this paper is based on the measurement of magnetic field in the air gap. Numerous studies have proven that crucial information about the machine condition can be determined based on measurement and analysis of the magnetic field in the air gap. It has also been confirmed that analysis of the air gap magnetic field can be used to detect, diagnose and recognize various electrical faults in their very early stage. Proposed method of positioning and installation of the measuring coils on ferromagnetic core parts within the air gap region of the machine enables differentiation of various faults. Furthermore, different faults can be detected if measuring coils are placed on the stator teeth then when placed on the rotor side. The paper presents method on how to analyse and process the measured voltages acquired from measuring coils placed within the machine, especially in the case of rotor static eccentricity detection. The methodology is explained by means of finite element method (FEM) calculations and verified by measurements that were performed on the induction machine. FEM calculation model was used to predict measurement coil output of the induction motor for healthy and various faulty states (at different amounts of static eccentricity). These results were then confirmed by measurements performed in the laboratory on the induction traction motor that was specially modified to enable measurements of faulty operation states of the machine. Measurements comprised of several machine fault conditions broken one rotor bar, broken multiple rotor bars, broken rotor end ring and various levels of rotor static eccentricity.
Other methods used for faults detection are primarily based on the monitoring of quantities such as current and vibration and their harmonic analysis. This new system is based on the tracing the changes of induced voltage of the measuring coils installed on the stator teeth. Faults can be detected and differentiated based on RMS value of these voltages and the number of voltage spikes of voltage waveform i.e. without the need of harmonic analyses. If these coils are installed on the rotor it is possible to detect the stator winding faults in a similar manner.
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Zhang, Xiangyong, Haipeng Liu, Yunli He, Tingrui Peng, Bin Su, and Huiyuan Guan. "Analysis of the Influence of Ferromagnetic Material on the Output Characteristics of Halbach Array Energy-Harvesting Structure." Micromachines 12, no. 12 (December 11, 2021): 1541. http://dx.doi.org/10.3390/mi12121541.
Повний текст джерелаАнотація:
Due to the particular arrangement of permanent magnets, a Halbach array has an significant effect of magnetism and magnetic self-shielding. It can stretch the magnetic lines on one side of the magnetic field to obtain an ideal sinusoidal unilateral magnetic field. It has a wide application range in the field of energy harvesting. In practical applications, magnetic induction intensity of each point in magnetic field is not only related to the induced current and conductor but also related to the permeability of the medium (also known as a magnetic medium) in the magnetic field. Permeability is the physical quantity that represents the magnetism of the magnetic medium, which indicates the resistance of magnetic flux or the ability of magnetic lines to be connected in the magnetic field after coil flows through current in space or in the core space. When the permeability is much greater than one, it is a ferromagnetic material. Adding a ferromagnetic material in a magnetic field can increase the magnetic induction intensity B. Iron sheet is a good magnetic material, and it is easy to magnetize to generate an additional magnetic field to strengthen the original magnetic field, and it is easy to obtain at low cost. In this paper, in order to explore the influence of ferromagnetic material on the magnetic field and energy harvesting efficiency of the Halbach array energy harvesting structure, iron sheets are installed on the periphery of the Halbach array rotor. Iron sheet has excellent magnetic permeability. Through simulation, angle between iron sheet and Halbach array, radian size of iron sheet itself and distance between iron sheet and Halbach array can all have different effects on the magnetic field of the Halbach array. It shows that adding iron sheets as a magnetic medium could indeed change the magnetic field distribution of the Halbach array and increase energy harvesting efficiency. In this paper, a Halbach array can be used to provide electrical power for passive wireless low-power devices.
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Brahim, LADGHEM CHIKOUCHE, Kamel Boughrara, Frédéric Dubas, Lazhar Roubache, and Rachid Ibtiouen. "Magnetic Field Calculation for Flat Permanent-Magnet Linear Machines Using a Hybrid Analytical Model." ENP Engineering Science Journal 1, no. 2 (December 31, 2021): 1–8. http://dx.doi.org/10.53907/enpesj.v1i2.36.
Повний текст джерелаАнотація:
This paper proposes an improved two-dimensional (2-D) hybrid analytical method (HAM) in Cartesian coordinates, based on the exact subdomain (SD) technique and the finite-difference method (FDM). It is applied to flat permanent-magnet (PM) linear machines with dual-rotor. The magnetic field solution is obtained by coupling an exact SD model, calculated in all regions having relative permeability equal to unity, with FDM in ferromagnetic regions. The analytical model and FDM are connected in both axes (x,y) of the (non-)periodicity direction (i.e., in the interface between the tooth regions and all its adjacent regions as slots and/or air-gap). To provide accuracy solutions, the current density distribution in slot regions is modeled by using Maxwell’s equations. It is found that, whatever the iron core magnetic parameters, the developed HAM gives accurate results for no- and on-load conditions. Finite-element analysis (FEA) demonstrates excellent results of the developed technique.
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Ladghem Chikouche, Brahim, Kamel Boughrara, Frédéric Dubas, and Rachid Ibtiouen. "Analytical magnetic field calculation for flat permanent-magnet linear machines with dual-rotor by using improved two-dimensional hybrid analytical method." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 40, no. 3 (August 12, 2021): 602–23. http://dx.doi.org/10.1108/compel-02-2021-0039.
Повний текст джерелаАнотація:
Purpose This paper aims to propose an improved two-dimensional hybrid analytical method (HAM) in Cartesian coordinates, based on the exact subdomain technique and the magnetic equivalent circuit (MEC). Design/methodology/approach The magnetic field solution is obtained by coupling an exact analytical model (AM), calculated in all regions having relative permeability equal to unity, with a MEC, using a nodal-mesh formulation (i.e. Kirchhoff’s current law) in ferromagnetic regions. The AM and MEC are connected in both axes (x, y) of the (non-)periodicity direction (i.e. in the interface between the tooth regions and all its adjacent regions as slots and/or air-gap). To provide accuracy solutions, the current density distribution in slot regions is modeled by using Maxwell’s equations instead of the MEC characterized by an equivalent magnetomotive force (MMF) located in slots, teeth and yokes. Findings It is found that whatever the iron core relative permeability, the developed HAM gives accurate results for no- and on-load conditions. The finite-element analysis demonstrates excellent results of the developed technique. Originality/value The main objective of this paper is to make a direct coupling between the AM and MEC in both directions (i.e. x- and y-edges). The current density distribution is modeled by using Maxwell’s equations instead of the MEC and characterized by an MMF.
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Jamolov, Umid, and Giovanni Maizza. "Integral Methodology for the Multiphysics Design of an Automotive Eddy Current Damper." Energies 15, no. 3 (February 4, 2022): 1147. http://dx.doi.org/10.3390/en15031147.
Повний текст джерелаАнотація:
The present work reports an integrated (experimental and numerical) methodology that combines the development of a finite element multiphysics model with an experimental strategy to optimally design an eddy current damper for automotive suspensions. The multiphysics model couples the whole set of time-dependent electromagnetic, thermal, mechanical, and fluid–wall interaction (CFD) partial differential equations. The developed FE model was validated against both literature model predictions and in-house experimental data. The electromagnetic model takes into account the magnetic material characteristics of the ferromagnetic material and iron poles. Loss separation and the Jiles–Atherton hysteresis models were invoked to determine the heat generated in the soft iron parts. The computation of the fluid–wall interaction phenomena in the air gap allowed for the prediction of the temperature field across the solid materials, including the magnets. The design of the EC damper addresses the effects of the geometries of the stator and rotor, as they are the most critical geometries for maximizing the functions of an eddy current damper. The magneto-thermal simulations suggested that the heating of the permanent magnets remains within a safe region over the investigated operational frequency range of the eddy current damper.
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Ladghem Chikouche, Brahim, Kamel Boughrara, Frédéric Dubas, and Rachid Ibtiouen. "Two-dimensional hybrid model for magnetic field calculation in electrical machines: exact subdomain technique and magnetic equivalent circuit." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 40, no. 3 (June 15, 2021): 535–60. http://dx.doi.org/10.1108/compel-01-2021-0008.
Повний текст джерелаАнотація:
Purpose The purpose of this paper is to propose a two-dimensional (2-D) hybrid analytical model (HAM) in polar coordinates, combining a 2-D exact subdomain (SD) technique and magnetic equivalent circuit (MEC), for the magnetic field calculation in electrical machines at no-load and on-load conditions. Design/methodology/approach In this paper, the proposed technique is applied to dual-rotor permanent magnet (PM) synchronous machines. The magnetic field is computed by coupling an exact analytical model (AM), based on the formal resolution of Maxwell’s equations applied in subdomains, in regions at unitary relative permeability with a MEC, using a nodal-mesh formulation (i.e. Kirchhoff's current law), in ferromagnetic regions. The AM and MEC are connected in both directions (i.e. r- and theta-edges) of the (non-)periodicity direction (i.e. in the interface between teeth regions and all its adjacent regions as slots and/or air-gap). To provide accurate solutions, the current density distribution in slot regions is modeled by using Maxwell’s equations instead to MEC and characterized by an equivalent magnetomotive force (MMF) located in the slots, teeth and yoke. Findings It is found that whatever the iron core relative permeability, the developed HAM gives accurate results for both no-load and on-load conditions. Finite element analysis demonstrates the excellent results of the developed technique. Originality/value The main objective of this paper is to achieve a direct coupling between the AM and MEC in both directions (i.e. r- and theta-edges). The current density distribution is modeled by using Maxwell’s equations instead to MEC and characterized by an MMF.
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Antonov, Yuri F. "Calculation, design and manufacture of heteropolar magnetic levitation and linear drive systems of maglev transport." Transportation Systems and Technology 7, no. 2 (July 1, 2021): 119–29. http://dx.doi.org/10.17816/transsyst202172119-129.
Повний текст джерелаАнотація:
Background: The methods of calculation and elements of the technology for creating heteropolar magnetic systems of levitation, lateral stabilization and a rotor-runner of a traction linear synchronous motor for the development of the transport technology "Russian Maglev" in order to achieve an increased levitation gap of 0.2 m, reduce the threshold speed of the exit vehicle in levitation mode up to 10 km/h.
Aim: to develop methods for calculating and designing heteropolar poles from elementary permanent magnets, coils of the same type based on composite low-temperature superconductors and high-temperature tape superconductors of the second generation and a step-by-step technology for their production.
Tasks:
Creation of an on-board magnetic system of levitation and lateral stabilization, allowing to provide a levitation gap of 0.2 m, a threshold value of vehicle speed of 10 km/h when transition to levitation mode, to reduce stray magnetic fields to the level of the natural field of terrestrial magnetism of 50 T;
Creation of a rotor-runner of a linear synchronous motor with an ironless stator with a power of 10 MW.
Methods: outlines the main calculation methodologies: "analysis" and "synthesis". The "analysis" methodology is adopted in solving the "direct" calculation problem, when the configuration of the magnetic system is set and the magnetic field in the working area is calculated, and, if necessary, the stray magnetic fields. This methodology can be effectively applied if there is experience in creating magnetic systems. Otherwise, the "synthesis" methodology is applied, which is used in solving the "inverse" calculation problem, in which the picture of the distribution of the magnetic field in the working zone is set and the configuration of the magnetic system is found (synthesized).
Results of the study performed:
The parameters and characteristics of high-energy permanent magnets made of rare-earth metals, low-temperature and high-temperature superconducting winding materials have been analyzed, the choice of permanent magnets and superconducting winding material has been made;
Calculations of the magnetic system of permanent magnets in the "Halbach assembly" and in the traditional assembly in a toothed ferromagnetic core have been carried out;
Calculations of a track coil with a rectangular cross-section of the winding are performed;
Methods for calculating and optimizing superconducting magnetic systems from a set of similar track modules have been developed;
Conclusions: The results of the performed fundamental research will allow starting the calculation, design and construction of conveyor-main passenger and freight lines of maglev transport, as well as urban public transport.
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Kolychev, S., and A. Sianov. "EXPERIMENTAL STUDY OF THE STATIC CHARACTERISTICS OF THE SYNCHRONOUS MACHINE IN THE MODE OF DYNAMIC BRAKING WITH INDUCTION RESISTANCE IN THE WINDING OF THE STATOR." Collection of scholarly papers of Dniprovsk State Technical University (Technical Sciences) 2, no. 37 (April 23, 2021): 22–27. http://dx.doi.org/10.31319/2519-2884.37.2020.5.
Повний текст джерелаАнотація:
The article discusses the results of a study of the static electromechanical characteristics of a synchronous machine (SM) when prototypes of induction resistances (IR) with improved parameters are included in its stator circuits.
Widespread in practice, dynamic braking (DB) of synchronous machines provides for the dissipation of the kinetic energy of the rotor in the resistance boxes included in the stator winding. In the process of stopping, to maintain the constancy of the average braking torque of the SM, a bulky relay-contactor shunt circuit for stator resistances is used. At low speeds, regulation of the excitation current of the SM or its forcing can also be applied. However, it is not possible to eliminate significant fluctuations in the electromagnetic moment in this way.
To optimize the SM DB process, instead of resistance boxes, it was proposed to include a three-phase induction resistance in the stator winding, the value of which automatically decreases along with the stator current frequency. This approach allows you to drastically reduce the number of contact equipment and ensure smooth braking of the machine with electromagnetic moment fluctuations within narrow limits. Known IR designs are designed for asynchronous motors with a phase rotor and satisfy the requirements of the given quality factor of their starting characteristics, but cannot ensure the constancy of the torque on the SM shaft in the DB mode.
Therefore, the objective of the work is to improve the design of the IR and obtain the necessary inhibitory mechanical characteristics of the SM using experimental studies.
The work provides a pilot plant diagram and a drawing explaining the design features of the IR.
The studies were performed for a synchronous machine, type МСА-72 / 4А, equipped with a thyristor exciter and a speed sensor. In three phases of the SM stator, IRs connected by a "star" were turned on. The experiments were carried out in the direction of obtaining the necessary braking characteristics of the SM by varying the design of the internal elements of the IR.
The figures show the mechanical characteristics of the SM obtained in the process of studying the effect on them of the thickness of the inner steel rings and massive ferromagnetic disks at three values of the fixed excitation current.
The research results show that the desired form of the mentioned characteristics of the SM is achieved only when using massive internal elements in the design of the IR. A separate figure shows the curves of changes in some values of the SM load, which will facilitate the development of methods for calculating the DB mode of the machine for the optimal design of the IR.
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Dewantara, Bima Dicky Anugrah, and Saiful Manan. "RANCANG BANGUN EXTERNAL ELECTROMAGNETIC RETARDERS SYSTEM PADA MOTOR 1 PHASA." Gema Teknologi 18, no. 4 (April 30, 2016): 1. http://dx.doi.org/10.14710/gt.v18i4.21908.
Повний текст джерелаАнотація:
Bima Dicky Anugrah Dewantara, Saiful Manan, in this paper explain that Electromagnetic retarders are generally known as electromagnetic inhibitors or brakes, the braking system eliminates most braking mechanics, thereby reducing conventional braking systems. Safety requirements and safety systems are developed and become a focal point of an equipment. Electromagnetic brakes are a safety component with a control system that is easy to control. With this electromagnetic brake, it will reduce maintenance costs, because it only requires a factor of electricity to be able to move it. The braking system uses electromagnetic forces to slow down a movement, which is generally a shaft motion. A dish with non-ferromagnetic metal material is attached to a rotating shaft. The disk is flanked by the side of the stator in the form of an electromagnetic coil system that can generate a magnetic field from electricity. Electric current generates a magnetic field in the coil. And the metal plate that cuts the magnetic field will cause eddy currents on the disk itself. This eddy current will generate a magnetic field whose direction is opposite to the previous magnetic field, thus inhibiting the rotary motion of the shaft. In designing, experimenting and making an External Electromagnetic Retarders System Design on 1 Phase Motor, use the NE 555 IC as the control duty cycle. So that the relationship between braking current and braking time is inversely proportional if the higher the current, the shorter the time it takes for the rotor to stop. And the relationship between braking current and motor current is directly proportional, by increasing the braking current will increase the load on the motor causing the motor current to increase. Keywords: Electromagnetic Retarders, Electromagnetic Brakes, Eddy Flow EffectReferencesTipler, P. 2008. Physics for Scientist volume 2. New York : WH Freeman and Company..Ishaq, M. 2007. Fisika Dasar Elektisitas dan Magnetisme. Yogyakarta: Graha Ilmu.Millman, Halkias, M.Barmawi, dan M.O.Tjia. 1971. Integrated Electronics:Analog and Digital Circuits and Systems. Jakarta : Erlangga.Ramdhani, Mohamad. 2008. Rangkaian Listrik. Jakarta : Erlangga.Bishop, Owen. 2004. Dasar-Dasar Elektronika. Jakarta : Erlangga.Halliday, David. Robert Resnick. 1978. Fisika Jilid II Edisi Ketiga. Jakarta : Erlangga
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Kostyrev, M. L., and Yu I. Lyutakhin. "Electromagnetic system of induction torque motors with ball hollow ferromagnetic rotors." Russian Electrical Engineering 80, no. 1 (January 2009): 41–44. http://dx.doi.org/10.3103/s1068371209010088.
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Potapov, L. A., and S. Yu Babak. "A comparison of electromagnetic brakes with disk and hollow ferromagnetic rotors." Russian Electrical Engineering 84, no. 2 (February 2013): 113–16. http://dx.doi.org/10.3103/s1068371213020107.
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Krzymień, Wiesław. "Mechanical Properties of the Package of Ferromagnetic Sheets." Transactions on Aerospace Research 2017, no. 1 (March 1, 2017): 54–62. http://dx.doi.org/10.2478/tar-2017-0006.
Повний текст джерелаАнотація:
Abstract The paper presents the measurement method and results as well as the results of comparative calculations aimed at determination of material data for the package of ferromagnetic sheets insulated with epoxy lacquer. During the test, the package of sheets was treated as a 3D orthotropic material. The values of Young’s and Kirchhoff’s moduli for a pre-compressed package of sheets, in accordance with the used manufacturing technology of the medium and high power electric motors’ rotors, were detennined. The carried out FEM comparative calculations confirmed that the determined mechanical parameters of the package of sheets as a 3D orthotropic material, i.e. Young’s and Kirchhoff’s moduli, for the compressive stress range of 1.0÷2.5 MPa, are included in the linear range. It was assumed that the determined mechanical properties of the package of sheets are necessary at the design stage for FEM simulation calculations of the electric motors’ vibration and strength properties. As a result of the tests, it was found that they should be repeated in order to determine the properties of other sheets or those coated with different insulating lacquer.
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Belyaev, E. F., and E. O. Kudryavtsev. "Mathematical model of induction capacitor motors with solid ferromagnetic rotors of composite material." Russian Electrical Engineering 81, no. 6 (June 2010): 277–81. http://dx.doi.org/10.3103/s1068371210060015.
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Tang, Xiaoning, Dawei Zhang, Zhenbo Li, and Jiapin Chen. "An Omni-Directional Wall-Climbing Microrobot with Magnetic Wheels Directly Integrated with Electromagnetic Micromotors." International Journal of Advanced Robotic Systems 9, no. 1 (January 1, 2012): 16. http://dx.doi.org/10.5772/45663.
Повний текст джерелаАнотація:
This paper presents an omni-directional wall-climbing microrobot with magnetic wheels. The integral design with an actuator and adhesive is realized by integrating stators and rotors of an MEMS-based electromagnetic micromotor with a magnetic wheel. The omni-directional wall-climbing mechanism is designed by a set of steering gears and three standard magnetic wheels. The required torque and magnetic force for microrobot movement are derived by its static analysis. The size of the magnetic wheel is optimized, with consideration of its own design constraints, by ANSOFT and Pro/Engineer simulation so as to reduce unnecessary torque consumption under the same designed load. Related experiments demonstrate that the microrobot (diameter: 26mm; height: 16.4; mass: 7.2g; load capacity: 3g) we have developed has a good wall-climbing ability and flexible mobility, and it can perform visual detection in a ferromagnetic environment.
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Titov, D. "ROTOR OPERATION IN THE VORTEX LAYER DEVICE." Bulletin of Belgorod State Technological University named after. V. G. Shukhov, March 13, 2020, 114–20. http://dx.doi.org/10.34031/2071-7318-2020-5-3-114-120.
Повний текст джерелаАнотація:
Vortex layer devices can be means of intensification of most processes. It is particularly effective to use these devices to produce rubber products, to accelerate chemical processes, to prepare raw materials in metallurgy, to use them in ore processing processes, to solve environmental problems in wastewater treatment and in many other areas. Such widespread use is possible due to the properties of the vortex layer, which, in addition to mechanical impact, also provides electrochemical effects. The efficiency of traditional devices of this class can be improved by using a new design. This design is characterized by the presence of a rotor in the working area, which actively affects electromagnetic processes. This article is devoted to the study of the rotor operation in the vortex layer device. The research is of a practical nature and consists in studying the operation of an experimental installation. The design of this installation makes it possible to identify patterns in the designated area of research. This is achieved by using easily removable rotors of different diameters, which allow getting a gap between the rotor and the inductor of different sizes. Also, the design of the experimental installation allows to enter a different number of ferromagnetic elements into the active zone. The main evaluation criterion for the study is the coefficient of energy use by the rotor. Estimating the absolute value of this coefficient, a conclusion is drawn about the futility of classical devices for mechanical impact on the product. The results of the study are to determine the dependence of the operating parameters on the gap between the rotor and the inductor, as well as the number of ferromagnetic elements in the device under study.
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Zhang, Wenzhong, Xutian Zou, and Junfeng Sun. "Influence of Electromagnetic Characteristics of Shaft Material on the Performance of Induction Motor." International Journal of Emerging Electric Power Systems 20, no. 5 (October 22, 2019). http://dx.doi.org/10.1515/ijeeps-2019-0080.
Повний текст джерелаАнотація:
Abstract Shaft is an important part of rotor, whose electromagnetic characteristics have an impact on the performance of the motor, especially when large diameter shaft and thin rotor yoke are adopted in the two-pole induction motor. Taking a 3 kW two-pole three-phase induction motor as an example, the two-dimensional electromagnetic field model of the motor is established by using finite element method. Firstly, by analyzing the difference of current, power factor, loss and magnetic field distribution of the motor with different shafts that are made from ferromagnetic and non-ferromagnetic materials. It is determined that the different magnetic saturation degree of rotor yoke is the key factor affecting the performance of motor when different shaft materials are used. Secondly, it is verified that the traditional analytic design method has the inaccurate design problem of the rotor yoke height due to neglecting the specific electromagnetic characteristics of shaft material. Finally, by comparing the differences of motor performance when several common magnetic shaft materials are used in motor shafts, the advantages of various shaft materials in improving motor performance are found. The presented results give guidelines to selecting shaft materials to improve motor performance.
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Zablodskiy, Nikolai, Vladyslav Pliuhin, Stanislav Fligl, and J. Lettl. "Dynamic Simulation of the Double-Stator Induction Electromechanical Converter with Ferromagnetic Rotor." SSRN Electronic Journal, 2013. http://dx.doi.org/10.2139/ssrn.3201921.
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Повстень, B. A., and Д. Аузеллаг. "Asynchronous short circuited motor with rods of rotor, divisible by large ferromagnetic plates." Proceedings of the National Aviation University 2, no. 1 (May 12, 1999). http://dx.doi.org/10.18372/2306-1472.2.9320.
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Xu, Yong, and Zhaohui Li. "Computational Model for Investigating the Influence of Unbalanced Magnetic Pull on the Radial Vibration of Large Hydro-Turbine Generators." Journal of Vibration and Acoustics 134, no. 5 (June 8, 2012). http://dx.doi.org/10.1115/1.4006648.
Повний текст джерелаАнотація:
A radial unbalanced magnetic pull (UMP) can be produced by an eccentric rotor and leads vibrations in large hydro-turbine generators. The influence of nonlinear UMP on the radial vibration of a large hydro-turbine generator is analyzed in this paper. The UMP is determined as a function of eccentricities and field currents by means of a simple analytical method instead of the finite element (FE) method. The analytical method employs the no-load characteristic curve of an electrical machine and saturation effects of the ferromagnetic materials are taken into consideration. FE rotor model of a large hydro-turbine generator unit, taking account of guide bearings, thrust bearing and periodic forces, is developed to investigate the influence of UMP on radial vibrations. The FE rotor model and the analytical method for UMP constitute the computational model. UMP is calculated under different rotor eccentricities and field currents by the proposed method. Comparing with other analytical methods, the effectiveness of the proposed method is verified. Dynamic responses of the FE model under different analytical methods for UMP are calculated to investigate the difference in vibration between different analytical methods. A simulated excitation test is performed and a comparative analysis between the calculated results and the field data is provided. The computational model is proved to be reasonable according to the analysis.
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McBain, J. "AN ELECTRO-MECHANICAL CONTROLLABLE-PITCH PROPELLER." Propellers & Impellers: Research, Design, Construction and Application, March 28, 2019. http://dx.doi.org/10.3940/rina.pro.2019.09.
Повний текст джерелаАнотація:
An electro-mechanical replacement for hydraulically-actuated controllable pitch propellers is described. The proposed mechanism applies a thread to the rotating shaft driven by the ship’s prime mover onto which a ferromagnetic nut is threadedly mated and spun by a stator-born electromagnet; the axial motion of the nut is used to manipulate the pitch of the rotatable blades. The design completely removes any mechanical coupling between the rotor and stator systems. An argument for the mechanism’s efficiency, ease of maintenance, and reduction of weight is provided in the form of reasoning by analogy for the already well studied differentiation between hydraulic and electric cylinders. Efficiency gains of 2-3 times, a doubling of mean-time-between failure, and a reduction of weight by 10% are inferred.
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Красношапка, М. Д., В. Н. Казак, and Т. А. Мазур. "Automatic control of process of design of the asynchronous muff with ferromagnetic cartridge on the secondary rotor." Problems of Informatization and Management 1, no. 25 (March 1, 2009). http://dx.doi.org/10.18372/2073-4751.1.6951.
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Zhao, Haisen, Chengyang Chu, Hassan H. Eldeeb, Yang Zhan, Guorui Xu, and Osama A. Mohammed. "Optimal Design of High-speed Solid Rotor Cage Induction Motors Considering Ferromagnetic Materials Behavior and Manufacturing Process." IEEE Transactions on Industry Applications, 2020, 1. http://dx.doi.org/10.1109/tia.2020.2984479.
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Jiang, Weilun, Yuzhi Liu, Avraham Klein, Yuxuan Wang, Kai Sun, Andrey V. Chubukov, and Zi Yang Meng. "Monte Carlo study of the pseudogap and superconductivity emerging from quantum magnetic fluctuations." Nature Communications 13, no. 1 (May 12, 2022). http://dx.doi.org/10.1038/s41467-022-30302-x.
Повний текст джерелаАнотація:
AbstractThe origin of the pseudogap behavior, found in many high-Tc superconductors, remains one of the greatest puzzles in condensed matter physics. One possible mechanism is fermionic incoherence, which near a quantum critical point allows pair formation but suppresses superconductivity. Employing quantum Monte Carlo simulations of a model of itinerant fermions coupled to ferromagnetic spin fluctuations, represented by a quantum rotor, we report numerical evidence of pseudogap behavior, emerging from pairing fluctuations in a quantum-critical non-Fermi liquid. Specifically, we observe enhanced pairing fluctuations and a partial gap opening in the fermionic spectrum. However, the system remains non-superconducting until reaching a much lower temperature. In the pseudogap regime the system displays a “gap-filling" rather than “gap-closing" behavior, similar to the one observed in cuprate superconductors. Our results present direct evidence of the pseudogap state, driven by superconducting fluctuations.
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Белова, Maryana Belova, Жданкин, Georgiy Zhdankin, Новикова, and Galina Novikova. "CREATION OF MICROWAVE INSTALLATION OF CONTAINER TYPE FOR HEAT TREATMENT OF BLOOD AND FAT-CONTAINING RAW MATERIALS." Vestnik of Kazan State Agrarian University, May 31, 2017, 74–78. http://dx.doi.org/10.12737/article_592fc7d6407e48.58575824.
Повний текст джерелаАнотація:
A microwave installation was created to boil waste products of poultry and animal slaughtering in a periodic mode. It consists of a horizontal cylindrical screening body. Inside it a perforated disc-rotor from non-ferromagnetic material, rotating the motor is installed. The cylindrical resonators are rigidly fixed on the periphery of the disc-rotor. Inside each resonator the removable dielectric heat resistant containers are mounted by clamps, which covers are perforated. The inner surface of the containers is covered with a silicone material. Microwave generator units are installed on the cover of shielded enclosure, opening with handles by hinges. At the base of the body there is a drain connection. To justify structurally and technological parameters of microwave installation we analyzed the changes in the electrical parameters of the muscle tissue, skin, bone, fat, depending on the frequency of electromagnetic fields exposure. The permittivity changes of raw materials, wavelength in the feed, penetration depth of electromagnetic radiation in the feedstock were also analyzed. The effect volume heating of inedible waste in the electromagnetic field is achieved due to penetration of the field into the feed to a considerable depth. At a certain depth of penetration it becomes possible to prove the form of processed raw material in resonator depending upon the requirements of the process and electromagnetic field parameters. The temperature and conductivity of the material greatly influence to the penetration depth.
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Tong, Wenming, Lu Sun, Mingjun Hou, Shengnan Wu, and Renyuan Tang. "Analytical Modeling for Rotor Eddy Current Loss of a Surface-Mounted PMSM with both Non-Ferromagnetic Conductive Retaining Sleeve and Shielding Cylinder." IEEE Transactions on Energy Conversion, 2021, 1. http://dx.doi.org/10.1109/tec.2021.3114095.
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КАШИН, Я. М., Л. Е. КОПЕЛЕВИЧ, А. В. САМОРОДОВ, and Е. А. МАРАХОВСКИЙ. "SIMULATION OF EMERGENCY MODES OF SEPARATOR UNIT." Известия вузов. Пищевая технология, no. 1(379) (March 28, 2021). http://dx.doi.org/10.26297/0579-3009.2021.1.15.
Повний текст джерелаАнотація:
Предложена конструкция сепараторной установки, отличающаяся от существующих тем, что ее основание выполнено с кольцевыми канавками полукруглого сечения, посредством которых ротор-барабан установлен с возможностью вращения на неферромагнитные шарики. Кроме того, подогрев сепарируемого продукта в установке осуществлен с использованием неизбежного тепловыделения в обмотках установки путем пропускания сепарируемого продукта по трубкам, которыми обвиты лобовые части обмоток установки. Для исследования аварийных режимов этой установки (обрывов фаз, короткого замыкания) и получения ее динамических характеристик разработана математическая модель в виде системы дифференциальных уравнений, описывающей взаимосвязи между ее параметрами (сопротивления обмоток статора и ротора, число витков в них) и параметрами переходных процессов (ударные токи, длительность переходного процесса). Смоделирована работа сепараторной установки при обрыве одного фазного провода с помощью пакета прикладных программ Simulink – Simulation and model-based design (MATLAB). Разработанная модель позволила оценить влияние параметров статора и ротора установки на переходный процесс в аварийных режимах и учесть это влияние на этапе проектирования. Преимущества предлагаемой установки – повышенная надежность, улучшенные энергетические и массогабаритные показатели. The design of the separator unit is proposed, which differs from the existing ones in that its base is made with circular grooves of semicircular cross-section, through which the rotor-drum is mounted with the possibility of rotation on non-ferromagnetic balls. In addition, the heating of the separated product in the installation is carried out using the unavoidable heat generation in the windings of the installation by passing the separated product through the tubes that are wrapped around the front parts of the windings of the installation. A mathematical model in the form of a system of differential equations describing the relationship between its parameters (the resistance of the stator and rotor windings, the number of turns in them) and the parameters of transients (shock currents, the duration of the transient process) has been developed to study the emergency modes of this installation (phase breaks, short circuits) and to obtain its dynamic characteristics. The operation of the separator unit in the event of a single phase wire breakage is modeled using the Simulink is a Simulation and Model-Based Design (MATLAB) application software package. The developed model allowed us to estimate the influence of the stator and rotor parameters of the plant on the transient process in emergency modes and to take this influence into account at the design stage. The advantages of the proposed installation are increased reliability, improved energy and weight and size indicators.
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Boness, T., K. Kudo, and T. S. Monteiro. "Doubly excited ferromagnetic spin chain as a pair of coupled kicked rotors." Physical Review E 81, no. 4 (April 2, 2010). http://dx.doi.org/10.1103/physreve.81.046201.
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