scholarly journals LINEAR ELECTRIC MOTOR WITH PM EXCITATION FOR A FREIGHT MAGNETOLEVITATION PLATFORM

2015 ◽  
Vol 1 (1) ◽  
pp. 77-90 ◽  
Author(s):  
Alexei S ADALEV ◽  
Vladimir G KUCHINSKII

The paper presents the design of a traction electric drive based on a linear synchronous motor with permanent magnets (PM) excitation. The electric drive is a part of the demonstration mock-up and is intended for the linear movement of a freight platform that is suspended in the air by means of the magnetic field. The drive performs a smooth movement of the platform with a required speed, platform stop, and changing of the direction of the movement. The motor inductor with permanent magnets is fixed on the platform whereas the motor stator is placed on the ground being supplied with power through а semiconductor converter. The stator consists of the independent modules that are sequentially connected to the converter as the inductor moves. Commutation of the modules and commutation the windings inside the active module is performed by the signals from some optical sensors attached to the inductor. Modular design of the motor stator and sectional feeding of its windings from the same converter allow to create a levitation mock-up with an arbitrary length of the motion path. At that all the technical solutions adopted in the drive design are directed to reducing of the drive production cost.

Vestnik IGEU ◽  
2020 ◽  
pp. 31-45
Author(s):  
T.H. Abuziarov ◽  
A.S. Plehov ◽  
A.B. Dar’enkov ◽  
A.I. Ermolaev

When designing electric drives based on brushless DC motors with permanent magnets (BLDC), which have low level torque pulsations, the problem of modelling non-standard topological solutions appears. The known models of BLDC motors are either based on the assumptions about the symmetry of the stator pa-rameters of the electric motor and/or the ideal form of the phase back-EMF waveform, which reduce the accuracy of evaluating the effectiveness of the proposed solutions or prove unusable for modelling an operation of the electric motor with a non-standard semiconductor converter. It is necessary to develop a mathematical model of the BLDC motor-based electric drive that takes into account the structural features of the electric motor and allows for semiconductor converter configuration variability. The model is designed in the Matlab Simulink environment. The verification is carried out by comparing the modelling results with experimental data obtained previously by other researchers. The proposed method for generating phase back-EMF in the BLDC motor model provides the possibility for the user to set the EMF form templates independent for each phase. The proposed method for stator circuit simulating provides the user with access to each of the stator windings leads as well as with the possibility of asymmetric determination of each parameter of the electric motor. Upon verification, it has been shown that the difference in the control points between the simulated and experimental speed-torque curves does not exceed 3,5 %. The developed model allows analyzing the static and dynamic characteristics of operation modes of non-standard topology BLDC motor-based electric drives taking into account the stator pa-rameters asymmetry and the real phase back-EMF waveform. The specified features of the model allow exploring the operation of the designed electric drive, taking into account the BLDC motor and converter design. The model can be applied when checking atypical design decisions and when changing the set parameters of the electric drive and restrictions on working conditions and target functions to refine the control system algorithms and automate the search for optimal parameters of the motor and the semiconductor converter.


Author(s):  
Igor' Polyuschenkov

The materials on the development of asynchronous electric drive with scalar control are given. The technical solutions associated with the design of software and hardware parts of the microprocessor control system are described. When developed, tools of model-based programming technique are used.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Kyungshik Lee ◽  
Chongdu Cho

The feasibility of a noncontact sensor is investigated. This type of sensor can potentially be used for torque measurement in a speed-variable power transmission system. Torque can be read by examining the phase difference between two induction signals from respective magnetic sensors that detect the magnetic field intensity of permanent magnets mounted on the surface of a shaft in rotation. A real-time measuring algorithm that includes filtering and calibration is adopted to measure the torque magnitude. It is shown that this new torque sensor can perform well under rotation speeds ranging from 300 rpm to 500 rpm. As an interim report rather than a complete development, this work demonstrates the feasibility of noncontact torque measurement by monitoring a magnetic field. The result shows an error of less than 2% within the full test range, which is a sufficient competitive performance for commercial sensors. The price is very low compared to competitors in the marketplace, and the device does not require special handling of the shaft of the surface.


2012 ◽  
Vol 721 ◽  
pp. 255-260
Author(s):  
Koichi Oka ◽  
Feng Sun ◽  
Akira Tsurumi ◽  
Gota Nakamura

This paper describes an analysis of torque characteristics of a noncontact spinning system using linearly actuated magnets. This noncontact spinning system spins the suspended object (here is an iron ball) without contact by the remanent magnetization and the linear movement of four permanent magnets. In this paper, the remanent magnetization point is modeled, and the rotational torque of this mechanism is calculated by IEM (Integral Element Method) analysis. The rotational torque is also measured using a measurement device with strain gauges. According to the IEM analysis results and the experimental results, the rotational torque characteristics of the noncontact spinning system are discussed.


2013 ◽  
Vol 10 (1) ◽  
pp. 73-84
Author(s):  
Baghdad Science Journal

Permanent magnets of different intensities were used to investigate the effect of a magnetic field in the process of preventing deposits of calcium carbonate. The magnets were fixed on the water line from the tap outside. Then heating a sample of this water in flasks and measuring the amount of sediment in a manner weighted differences. These experiments comprise to the change of the velocity of water flow, which amounted to (0.5, 0.75, 1) m/sec through the magnetic fields that are of magnetic strength (2200, 6000, 9250, 11000) Gauss, and conduct measurements, tests and compare them with those obtained from the use of ordinary water.The results showed the effectiveness of magnetic treatment in reducing the rate of deposition of calcium carbonate where up to 60% after treatment, and this percentage is increasing with increasing magnetic field strength where up to 85% when the intensity of the magnetic field 9250 and 11000 Gauss at the velocity of the water flow of 0.75 m/sec. This percentage of reducing was investigated with increasing the velocity of flow of water through a magnetic field. Also the results showed an increase in total dissolved solids (TDS) as well as electrical conductivity and a decrease in the value of surface tension as a result of magnetic treatment.Observation with the photograph pictures of the distillation apparatus oriented in several laboratories, that the amount of sediment formed a thick layer in the device-free magnetic treatment, but it was not dense and in the few quantity in the apparatus treated with magnetic intensity (8000, 9250) Gauss.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 630
Author(s):  
Tomasz Chady ◽  
Ryszard D. Łukaszuk ◽  
Krzysztof Gorący ◽  
Marek J. Żwir

This paper proposes and experimentally investigates a novel nondestructive testing method for ferromagnetic elements monitoring, the Magnetic Recording Method (MRM). In this method, the inspected element must be magnetized in a strictly defined manner before operation. This can be achieved using an array of permanent magnets arranged to produce a quasi-sinusoidal magnetization path. The magnetic field caused by the original residual magnetization of the element is measured and stored for future reference. After the operation or loading, the magnetic field measurement is repeated. Analysis of relative changes in the magnetic field (for selected components) allows identifying applied stress. The proposed research methodology aims to provide information on the steel structure condition unambiguously and accurately. An interpretation of the results without referring to the original magnetization is also possible but could be less accurate. The method can be used as a standard technique for NDT (Non-Destructive Testing) or in structural health monitoring (SHM) systems.


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