Analysis Of Linear Induction Motor Research Articles

Field Modeling and Thrust Analysis of Linear Induction Motor Considering Edge-End Effect and Core Saturation

Field Modeling and Thrust Analysis of Linear Induction Motor Considering Edge-End Effect and Core Saturation

A Novel MMF Distribution Model for 3-D Analysis of Linear Induction Motor With Asymmetric Cap-Secondary for Metro

This paper develops a novel magnetomotive forces (mmfs) distribution model along the transverse direction for the 3-D analysis of linear induction motor, and it investigates the influence of a laterally asymmetric cap-secondary on the thrust, vertical force, lateral force, and efficiency in a prototype single-sided linear induction motor for linear metro. First, the mmf distribution model and its working conditions are defined, and the model is transferred into a mathematical model. Second, the air-gap flux and secondary eddy current in a prototype linear motor with a cap-secondary are obtained by a 3-D space harmonic analytical method. Third, the thrust, vertical force, lateral force, and efficiency of the test motor are analyzed with various lateral deflection, and the power factor in secondary is also presented. Finally, these results are experimentally verified by measurements on the test rig of the linear motor, and the comprehensive effect on the operating performance can be accurately calculated by the mmf model.

Influences on performance in 3D analysis of linear induction motors with different transverse m.m.f. models in winding end‐regions

Since the three-dimensional (3D) analysis of linear induction motor (LIM) needs to consider the transverse end effect, the transverse magnetomotive force (m.m.f.) distribution model becomes significantly important. This study investigates the influences of different transverse m.m.f. models on operating characteristics of double-sided LIMs, and it also develops a novel m.m.f. model. First, four types of hypothetical distribution models are put into a 3D analytical method that considers the longitudinal and transverse end effects. Second, variations of the thrust, lateral and vertical forces with the models are comprehensively investigated in the possible operating regions. Besides, the calculated results are validated by finite elements method results and measurements in a prototype double-sided linear induction motor (DLIM). Finally, the model presented in this study can be considered as a kind of optimal model for analysing DLIMs, and comparisons with other models in each operating region are mentioned.

Design, Analysis of Linear Induction Motor based on Harmony Search Algorithm and Finite Element Method

Design, Analysis of Linear Induction Motor based on Harmony Search Algorithm and Finite Element Method

Experimental Analysis of Linear Induction Motor under Variable Voltage Variable Frequency (VVVF) Power Supply

This paper presents the complete analysis of Linear Induction Motor (LIM) under VVVF. The complete variation of LIM air gap flux under ‘blocked Linor’ condition and starting force is analyzed and presented when LIM is given VVVF supply. The analysis of this data is important in further understanding of the equivalent circuit parameters of LIM and to study the magnetic circuit of LIM. The variation of these parameters is important to know the LIM response at different frequencies. The simulation and application of different control strategies such as vector control thus becomes quite easy to apply and understand motor’s response under such strategy of control.

Performance Analysis of Linear Induction Motor of Electromagnetic Catapult

Based on the operating principle of linear induction motor (LIM), this paper has analyzed the performance of the LIM consisting of a long sectioned transverse flux stator and a short flat aluminum mover, proposed the basic requirements and working modes of this special type of a catapult, described the optimal design methods of the LIM and discussed in detail some important parameters affecting the operating performance, such as the slot width, pole pairs, and the thickness of the mover. Then, the optimal system design and the discussion of performance are carried out based on the T-type equivalent circuit model with the covered and uncovered sections. The phase current, phase voltage, power capacity, and height are 11359 A, 3000 V, 409 MVA, and 1.73 m, respectively. The launch profile is also derived from the model. To verify the electromagnetic compatibility of the LIM, the 3-D magnetic model is established. The results show that the magnetic fields fall to the earth's ambient level at 1 m above the stator, which cannot bring low-frequency electromagnetic interference to the environment.

Evaluation of electromagnetic characteristics for linear induction motor using finite element method

It is important to evaluate the electrical & magnetic characteristics of linear induction motor to improve its design for best performance. Computer simulation using the finite element technique is very useful for achieving the objective. This attempt has been made to get the simulation analysis of linear induction motor which includes flux distribution, surface current density & magnetic vector potential etc. finite element method is used here to evaluate the electromagnetic behavior of the object by changing primary core material to get the comparative performance analysis with different materials used. The simulation work has been carried out using Ansoft’s Maxwell software Package.

Surface charge analysis in eddy current problems

AbstractTo estimate the characteristics of electric machines that have conductors of complicated shape, it is effective to analyze the surface charge related to eddy current phenomena. However, the eddy current field is generally treated as a quasi‐static field in which the displacement current is neglected and the electric field is not defined in the nonconductive region in the calculation process. Therefore, when we use only the A–ϕ finite element method (FEM) as a field analysis method, it is difficult to calculate the surface charge directly at the interface between conductive and nonconductive regions. In this paper, with this background, we propose a novel method of analysis of the surface charge based on both the A–ϕ FEM with edge elements and the integral equation. This approach enables us to precisely calculate the surface charge. Some numerical results that demonstrate the validity of the proposed method are also presented, such as the surface charge analysis of linear induction motors for evaluating the relationships among the surface charge, eddy current, and conductor shape. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(1): 59–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10173

Standstill Thrust Characteristics Analysis of Linear Induction Motor with Two Armatures Using 3-D Finite Element Method

Standstill Thrust Characteristics Analysis of Linear Induction Motor with Two Armatures Using 3-D Finite Element Method

Surface Charge Analysis in Eddy Current Problems

To estimate characteristics of electric machines that have conductors with complex form, it is effective to analyze the surface charge concerned with eddy current phenomena. However, the eddy current field is generally treated as quasi-static field in which the displacement current is neglected and the electric field is not defined in the non-conductive region in the calculating process. Therefore, when we adopt only the A-φ FE method as a field analysis method, it is difficult to directly calculate the surface charge at the interface between conductive and non-conductive regions. In this paper, with this background, we propose a novel analysis method of the surface charge based both on the A-φ formulation of 3D edge FE method and on the integral equation. This approach enables us to precisely calculate the surface charge. Some numerical results, which demonstrate the validity of the proposed method, are also presented, e. g., the surface charge analysis of linear induction motors for evaluating the relationships among the surface charge, eddy current, and conductor shape.

3-D finite element analysis of a linear induction motor

This paper presents the thrust characteristics analysis of linear induction motors (LIMs) using the 3-D finite element method (3-D FEM) with edge elements taking into account eddy currents. LIMs have advantages of simple structure, easy maintenance, less environmental pollution and so on. Therefore, they are widely used for high speed transport systems in clean rooms and hospitals. However, it is difficult to analyze the thrust characteristics of LIMs numerically because of the three dimensional shape. In this paper, we calculate the thrust of a LIM using the 3-D FEM. It is clarified that the validity of the 3-D FEM by comparison of the calculated and measured results.

End effect analysis of linear induction motor based on the wavelet transform technique

The performance of LIM is degraded due to the influence of the end effects. LIM is analyzed using the Fourier series expansion to throw light on this problem. However, when we want to obtain the high-accuracy in this technique, the number of times for calculation is increased. In the case of the wavelet transform technique, as the wavelet coefficients converge rapidly to zero, this technique has been applied to analyze the end effects of LIM. In this paper, we investigated the method for determining mother wavelet.

Characteristics analysis of linear induction motor with two types of secondary structure based on electromagnetic field and electric circuit analysis

In this study, we attempt to analyze characteristics of single-sided Linear Induction Motor with a short primary member and a complicated secondary structure, which consists of solid-plate conductor section and a winding one. For this purpose, electromagnetic field analysis by 3-D FEM is combined with electric circuit analysis and motion equation. Here, electric circuit analysis involves the primary and secondary windings. Focusing on the distributions of secondary induced current and thrust force, we discuss various transient phenomena that develop at the boundary between different secondary structures. Finally, to suppress the aggravation of characteristic caused by the secondary structural transition, we improve the boundary.

Performance analysis of a new electroplating line configuration with a linear induction motor based material mover

A high-performance linear induction motor (LIM) can be used to increase material transfer speeds by an order of magnitude over conventional equipment. In this paper, we develop queueing network models for performance analysis of LIM based material mover in a new configuration for electroplating lines.

Linear Drive Systems and their Related Technologies. Three-Dimensional Finite Element Analysis of Linear Induction Motors with a skewed ladder-type secondary.

The slot harmonics produce a cogging torque and a crawling in a linear induction motor (LIM) with a ladder type rotor. To avoid those defects, we sometimes adopt the V-skewed rotor (or stator) which rise no lateral force. In this paper, we investigate the skew effect by the three-dimensional finite element analysis with A-φ method and specify significant points for adopting skewed slots.Based on the above approach, we evaluate the skew effect in the LIM, comparing it with the experimental data to confirm the validity of the analysis. The follows are confirmed: (1) the improvement of the cogging torque by introducing V-skewed rotor; (2) the decrease in the thrust force and increase in the sucking force as making the skew angle bigger, and the abnormal temperature rising in V-skewed rotor; (3) the decrease of the abnormal temperature rising by optimizing the shape of rotor; (4) the validity of the skewed stator for short stator machines. And we propose a method that put two stators skewed in the opposite direction to each other for the double-sided LIM.

Comparison of the use of simple space transient and finite element analysis for linear induction motor calculation

The paper is concerned with the analysis of linear induction motors. It compares the use of an early simple space transient analysis with finite element modelling using the A/spl psi/ method for 3D problems and the Minkowski transformation for moving conductor regions. Special attention was paid to the effect of the geometry of the trailing edge of the machine.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Analysis of Linear Induction Motors with the Control Volume Technique.

Two-dimensional time dependent field calculation is mathematically formulated, using the “Control Volume Technique” for investigating the electromagnetic characteristics of linear induction motors (LIMs). The velocity term in the magnetic potential equation has been introduced using the identified technique. This modification was necessary in order to avoid possible mathematical instabilities during computations execution due to the presence of the velocity term in the diffusion equation. In the present analysis, end-effects were eliminated using periodical boundary conditions in the numerical solutions. It is revealed that, even with the absence of end-effects, the thrust-slip frequency characteristics are dependent on the secondary speed of the linear induction motor under investigation.

An upwind Galerkin finite element analysis of linear induction motors

An upwind Galerkin finite-element method (GFEM) for electromagnetic problems in moving media is proposed. In the conventional GFEM, when the cell Peclet number becomes greater than the critical value of 2, many undesirable flux loops due to oscillatory solutions appear in the flux plots. It is shown that the upwind GFEM can stabilize such oscillations successfully. Although the extra-fine subdivision of elements makes it possible to suppress such oscillations without upwinding, the 13 mm length of a mesh in the present model must be subdivided into 2.43 mu m in order that the Peclet number in the back iron shall not exceed the critical value of 2 or there will be a need for enormous computation time and memories. For this reason, the present GFEM is the most promising numerical method for convective diffusion equation solvers with larger cell Peclet number.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Simplified two-dimensional analysis of linear induction motors

A method for simplified computing the performance of linear induction motor is presented. This analysis is derived from the two-dimensional electromagnetic analysis using the space harmonic technique based on the Fourier series expansion. The resultant method would be a interface between the Fourier series and Fourier transforms, and can make a substantial abbreviation in the calculation without spoiling the accuracy, taking directly into account of the end effect, the skin effect and the primary winding arrangement.

Motional eddy currents in a nonmagnetic conducting laminate backed with an iron substrate

This paper discusses the eddy currents induced in a nonmagnetic conducting laminate on an iron substrate. These results are applicable to the analysis of linear induction motors, ordinary induction machines with sleeve rotors, and eddy current couplings. Under appropriate assumptions it is shown that the boundary conditions and Ampere’s circuital law reduce the problem to eight linear simultaneous equations. Simple algebraic expressions for the current density and power dissipation in the laminate are obtained in terms of the solutions of the above simultaneous equations. Numerical results for typical situations are presented, and a brief discussion of the experimental verification of the analysis is presented.