Characteristics Of Linear Induction Motor Research Articles

Methodology for calculating the characteristics of linear induction motors for low-speed process equipment

An analysis of the drive characteristics of technological machines and mechanisms of agricultural production showed that their working bodies in 56.3% of cases have rotational motion, and in 43.7% they have translational motion. Special electromechanical and electromagnetic converters - an electric drive with a linear asynchronous motor - are very promising for driving the working bodies of technological equipment that perform translational and oscillatory motion, as well as rotational motion with a rotation speed of up to 500 min−1. A linear asynchronous electric drive makes it possible to implement technologically specified drive characteristics, integrate the power parts of an electric motor with a working body with the exception of mechanical converters, while reducing material and energy consumption, increasing operational reliability of process equipment as a whole. The choice of the optimal winding scheme and the design of the magnetic circuit of the inductor, the material of the secondary element increases the energy and traction performance of the linear induction motor. The study and modeling of electromagnetic processes and the optimization of geometric dimensions, winding data of the inductor and electrical parameters can be effectively carried out on a mathematical model of a linear induction motor by a numerical method, represented by a system of three matrix equations describing the states of the magnetic and electrical circuits of the machine, detailed to the level of tooth division and winding section.

ПРИМЕНЕНИЕ ЛИНЕЙНЫХ АСИНХРОННЫХ ДВИГАТЕЛЕЙ ДЛЯ ВЫСОКОСКОРОСТНОГО НАЗЕМНОГО ТРАНСПОРТА

Magnetic suspension in high-speed ground transport systems is an alternative to the rail wheel. The successful solution to the development of high-speed ground transport is largely determined by the creation of operationally efficient linear motors, the main task of which is to convert electrical energy into mechanical energy and create tractive force to ensure the movement of the crew according to a given program in the range of operating speeds. The article investigates linear asynchronous motors with longitudinal closure of magnetic flux of single-ended design. As a result of investigation of physical processes in linear motors caused by edge problems it was found that the cause of the transverse edge effect is the finite width dimensions of the reactive bus, the change of which causes closure of eddy currents within the active area of inductor, leads to weakening of magnetic field in the central zone and to reduction of tractive force. The discrepancy between the calculated and experimental indicators of physical processes in linear asynchro- nous motors due to significant idealization of mathematical models led to the development of a three-dimensional theory, brought to the calculation programs. The developed calculation program of electromechanical characteristics of linear induction motors with inductor and reactive bus layout, as well as their geometrical and physical parameters allows to determine the necessary integral motor characteristics in the form of a levitation function.

Improved vector control strategy of linear induction motors for electromagnetic launch

Due to the change of parameters caused by the dynamic longitudinal end effect, the operation characteristics of linear induction motors (LIMs) applied in an electromagnetic launch field are different from that of ordinary LIM. Due to the continuous increase of the LIM port voltage under high acceleration, the phase voltage is close to the inverter output limit. The conventional indirect field-oriented control (IFOC) strategies of LIM based on the flux attenuation compensation or maximum thrust control cannot solve the problem well. Based on the LIM mathematical model, this study analyses the output thrust characteristics of the LIM and discusses different control methods. This study presents an improved vector control strategy. By dynamically adjusting the value of ‘ k ’ based on the moving speed of the LIM, the maximum thrust output is maintained at medium and low speeds, and the voltage rise of a motor port is restrained at high speed. The effectiveness of the proposed control method is verified by simulation and experiment. The method proposed in this study is helpful to broaden the application of the LIM in the higher speed field.

Distribution of Static Magnetic Field Characteristics of Linear Induction Motor

In this paper, theoretical and practical design of low speed single side linear induction motor of secondary as reaction rail is proposed. At no load condition, a DC voltage is injected to the stator winding to one of the phase to analyse the static magnetic field across the mean length and also to the other phases dc voltage is injected and analysed that the magnetic flux shift spatially that makes the flux travels from one end of the primary to the other end. For increasing input dc current the magnetic flux density also increases by its square. By applying ac voltage, the output speed, thrust characteristics are measured. The static magnetic field and output characteristics of linear induction motor had analysed through experimental calculations.

컨테이너 검색기 이송대차 추진용 선형 유도전동기의 2차측 리액션플레이트 재질에 따른 특성 연구

This paper presents the analysis of the analysis of thrust characteristics of linear induction motors(LIMs) according to secondary reaction plate. LIMs are well known as high speed transport systems, which can obtain thrust directly without gears and links, or auxiliary mechanisms. A simple structure, easy maintenance, and less environmental pollution are advantages of LIMs. In transport systems using LIMs, the secondary reaction plate is an important design factor, because it has considerable impact on the cost of the railway as well as the performance of the LIMs. This paper deals analyzed the characteristics of linear induction motor used for moving the vehicle of container scanner. Thrust, efficiency and load characteristic were interpreted with FEM regarding two models whose material of secondary reaction plate was copper and aluminum. It suggested the interpretation of thrust, efficiency and power factor characteristic along slip and compared the operation ability of linear induction motor through characteristics analysis along the load.

Characteristic Analysis of a Linear Induction Motor for 200-km/h Maglev

As a result of the current population concentrations in urban centers, demand for intercity transportation is increasing rapidly. Railway transportation is becoming popular as an intercity transportation because of its timely service, travel speeds and transport efficiency. Among the many railway systems, the innovative and environmentally friendly maglev system has been rated very highly as the next-generation intercity railway system. Linear induction motors are widely used for the propulsion of maglev trains because of their light weight and low construction costs. The urban maglev that was recently completed in Incheon airport site employs a 110km/h class linear induction motor. However, this system was designed to meet requirements for inner-city operations and is not suitable as an intercity transportation system, which requires medium to high speeds. Therefore, this study deals with the characteristics and designs of linear induction motors used for the propulsion of maglev trains that can be used as intercity trains. Rail car specifications for highspeed trains have been presented, and the characteristics of linear induction motors that can be used for the propulsion of these trains have been derived using the finite element method (FEM).

Characteristics of Linear Induction Motor Considering Material of Reaction Plate Change

In this paper, a method of calculating the parameters of equivalent circuit model of linear induction motor(LIM) is proposed based on numerical analysis and finite element method(FEM). The method is proved accurately through the traditional removed and locked tests. Material change of reaction plate’s effect on how equivalent circuit’s parameters change and the influence on thrust and vertical force are analyzed through this method. The co-simulation of Maxwell and SIMULINK is analyzed. A control algorithm to compensate the effect of material change is presented. The compensation is based on equivalent circuit parameters variation and indirect vector control. Simulation results have shown the algorithm had good performances.

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.

Study on the Braking Characteristics of Linear Induction Motors

This paper presents the research results of the braking characteristics of linear induction motors. The spectrum analysis method of the magnetic fields is used. There were derived the expressions of the elementary components of the continuous spectrum amplitudes of the braking current volumic density and primary magnetic field as well as their characteristics were investigated. The assessment of the elementary components of higher frequency allows the increase of accuracy when calculating the characteristics of braking. For the simulation of the magnetic field of the dynamic braking there was applied the software package Maxwell. The received results indicates that there exist the transversal and longitudinal edge effects which influence the characteristics of braking. Ill. 7, bibl. 5 (in English; abstracts in English and Lithuanian).DOI: http://dx.doi.org/10.5755/j01.eee.118.2.1172

Measurement of Drive Characteristics of Linear Induction Motor with Experimental Equipment Implemented Disc-shaped Secondary Side

The ordinary experimental equipment has a long stroke or a large cylindrical rotating secondary side in order to measure the drive characteristics of Linear Induction Motor (LIM). In this paper, we propose the measurement method of the drive characteristics of LIM with the experimental equipment implemented a disc-shaped secondary side. This method makes the experimental equipment smaller in size. It has been shown that the drive characteristics of LIM can be successfully measured.

Investigation of Linear Induction Motor According to Secondary Conductor Structure

This paper presents the analysis of single-sided linear induction motors (SLIMs) for application in various systems demanding direct linear motion. In order to investigate the characteristics of linear induction motors according to secondary conductor structures, five types of secondary slot shape structures, usually used in rotary motors, were set up. The equivalent circuit of a SLIM is proposed and the equivalent parameters are computed. In addition, the characteristics such as the air-gap flux density, thrust, normal force, force ripple, speed response, etc., are analyzed by 2-D FEM with an external circuit, and the results are compared.

Obtaining the operating characteristics of linear induction motors: a new approach

We modified, by means of the finite-element method (FEM), the model suggested by Duncan (Proc. IEE, pt. B, vol. 130, no. 1, 1983) for simulation of linear induction motors. The modified model covers the special phenomena in linear motors such as transverse edge effect, longitudinal end effect, and saturation of back iron. The modified model first computes the level of saturation by simple equations and an iterative method. Then, using the FEM, it computes the equivalent circuit parameters. Finally, it uses the Duncan model to account for the end effect. The modified model thus can be used to design linear induction motors. Furthermore, the change in equivalent circuit parameters at different operating conditions can be taken into account. A comparison of the simulation results based on the proposed model with experimental measurements shows the high accuracy of the model.

Comparison of the Characteristice of Linear Induction Motors with Various Secondary-Side Conductors on the Basis of the Simple Calculation Method Using DC Decay Test

This paper presents a method to calculate the characteristics of linear induction motors by a simple standstill testing method using a small-capacity DC power supply unit, tentatively called the DC decay testing method. This method can determine by a single test the accurate impedance of linear induction motors from the vicinity of commercial frequencies to less than 0.1Hz. The characteristics at each slip are predicted using the two-reaction theory. Comparisons of measured and calculated results for starting thrusts and starting currents demonstrate the validity of the proposed testing method. In addition, we evaluate how conditions (i.e., gap, structure and material) of the secondary-side conductor affect the linear induction motor's performance, i.e., thrust, current and impedance characteristics as calculated by the proposed testing method. This method is suited to calculating the performance of linear induction motors because it does not require no-load tests, which is difficult to carry out for linear induction motor for control use, or locked tests, where the mover must be braked.

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.

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.

Dynamic characteristics of linear induction motor for urban transit under constant V/f drive

Dynamic characteristics of linear induction motor for urban transit under constant V/f drive

Dynamic characteristics of linear induction motor for urban transit under constant V/f drive.

Dynamic characteristics of linear induction motor for urban transit under constant V/f drive.

Experimental study on characteristics of linear induction motor for urban transit.

Experimental study on characteristics of linear induction motor for urban transit.

Calculation of a device for recording characteristics of linear induction motors

Calculation of a device for recording characteristics of linear induction motors

Influence of End-effect on Characteristics of Linear Induction Motor

Influence of End-effect on Characteristics of Linear Induction Motor