File Name: construction and working principle of linear induction motor .zip
A linear induction motor is a developed version of cylindrical induction motor. It is special type of induction motor which gives linear motion instead of rotational motion as in the case of a conventional induction motor.
Linear Induction Motor LIM is an asynchronous motor, working on the same principle an Induction Motor works, but is designed to produce the rectilinear motion, unlike the rotary movement produced by a motor; hence the word Linear Induction Motor.
The motor which works on the principle of electromagnetic induction is known as the induction motor. The electromagnetic induction is the phenomenon in which the electromotive force induces across the electrical conductor when it is placed in a rotating magnetic field. The stator and rotor are two essential parts of the motor.
Whereas in the year , the operating model was brought into development by Hermann Kemper, and the full-size operating version was introduced by Eric in the year Then after, this device was employed in many applications across many industries.
This article gives clearly explains Linear Induction Motor , its working principle, performance, design, construction, advantages and disadvantages and major applications. Let us dive into the concept. Linear Induction Motor is abbreviated as LIM and this is the enhanced version of the rotary induction motor where the output is linear translational motion in the place of rotating motion.
This device generates linear movement and force other than the rotating torque. The design and the functionality of the linear induction motor can be shown in the below figure by creating a radically shaped cut in the revolving induction and thus leveling the section. The output is a leveled stator or the upper side having iron-plated laminations where these carry three-phase multiple poles winding having conductors which are in 90 0 angles to the motion direction.
It also consists of squirrel enclosed type of winding whereas it is generally included with an endless aluminum or copper made sheet which is kept on solid plated iron support. Regardless of the device name, not all the linear induction motors generate linear movement, few of the device generate are utilized for delivering revolutions having great diameters and the utilization of the endless primary sections is more costly.
The fundamental construction and linear induction motor design almost correspond the same as three-phase induction motor, even though it does not appear like that of a normal induction motor. When a cut is formed in the stator section of the polyphase induction motor and placed on a flat surface, then this creates the primary section of the linear induction motor.
In the same way, when a cut os formed in the rotor section of the polyphase induction motor and placed on a flat surface, then this creates the secondary section of the linear induction motor.
This model has a primary section that is placed on another end of the secondary section. This design is used for enhancing the utilization of flux on both the primary and secondary sides. This is the construction of a linear induction motor. The below section provides a clear explanation of the working of linear induction motor. Here, when the primary section of the motor is energized by using a balanced three-phase power, then there will be flux movement all across the length of the primary section.
This linear movement of the magnetic field is equal to the revolving magnetic field in the stator section of the three-phase induction motor. With this, there will be the induction of electric current in the conductors of the secondary winding because of comparative movement in between the conductor and flux movement.
The current that is induced gets in connection with the flux movement to generate either linear thrust of force and this is shown by. When the primary section is made to be constant and the second section has movement, then the force pulls the secondary section in its direction itself and this results in the generation of necessary rectilinear movement.
When a power supply is provided to the system, the generated field will provide a linear moving field where the velocity is represented as per the above-mentioned equation. In correspondence to the same justification, in the condition of induction motor, the secondary runner does not hold the same speed as the speed value of the magnetic field. Because of this, there generates a slip. The end effect consists of efficiency and performance losses which are the consequence of magnetic energy that is carried away and dropped at the ending of the primary section through the relative motion of the primary and secondary sections.
Only with the secondary section, the functionality of the device seems to be the same as the rotary machine, required that it is nearly two poles apart but having a minimal primary reduction in the thrust which happens at low slip still it is either 8 or more poles longer.
With the existence of end effects, LIM devices do not hold the ability to run light, whereas the general kind of induction motors holds this ability to operate the motor having a closer synchronous field under minimal load circumstances. Opposing this, the end effect generates corresponding losses having linear motors. The drive that is caused by the LIM devices is almost the same as that of general induction motors.
These drive forces represent an approximately same characteristic curve the same as slip, even though modulated by the end effects. This is also termed as a Tractive effort. It is shown by. This takes place only in single-sided motors and this characteristic will not generally happen when an iron supporting plate is utilized for the secondary section because this creates an attraction that overcomes the lifting pressure.
Linear Induction Motors also exhibit a Transverse edge effect which is that the current paths that are in the same direction of movement develop losses and because of these paths, there will be a reduction in the effective thrust. As because of this transverse edge effect takes place. The performance of the linear induction motor can be known by the below-explained theory where the synchronous speed of the moving wave is represented by.
In the case of a rotary induction motor, the speed of the secondary section in the LIM is less than that of the synchronous speed and is given by. When there is a comparison between LIM and rotary induction motor, the linear induction motor needs an increased air gap and because of this, there will be increased magnetizing current and the factors like performance and power factor will be minimal.
In the case of RIM, the area of the stator and rotor sections is similar, whereas in LIM one is shorter than the other section. At constant speed, the shorter section will have continuous passage than that of the other. On the whole, this is all about the concept of Linear Induction Motors. This article has provided a clear explanation of linear induction motor principles, design, working, uses, benefits, and drawbacks.
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A Linear Induction Motor LIM is an advanced version of rotary induction motor which gives a linear translational motion instead of the rotational motion. The stator is cut axially and spread out flat. In this type of motor, the stator and rotor are called primary and secondary respectively. The secondary of the linear induction motor consists of a flat aluminium conductor with a ferromagnetic core. If the stator is cut along the line ab and spread out flat the figure formed is shown below. This portion forms primary of the LIM. If a three phase supply is connected to the stator of an induction motor, a rotating flux is produced.
The simplest form of construction of a Linear Motor is as simple as a three phase induction motor. It has three phase winding housed in slots in a field system. It is simply the primary winding on a stator in case of an induction motor. The "stator" is laid out in the form of a track of flat coils made from aluminum or copper and is known as the "primary" of a linear motor. The "rotor" takes the form of a. In this type of motor, the stator and rotor are called primary and secondary respectively. The secondary of the linear induction motor consists of a flat Aluminium conductor with a ferromagnetic core.
PDF | This paper explores the construction process of a linear induction motor (LIM), the basic working principle of a LIM, enabling handling of mathematical.
Whereas in the year , the operating model was brought into development by Hermann Kemper, and the full-size operating version was introduced by Eric in the year Then after, this device was employed in many applications across many industries. This article gives clearly explains Linear Induction Motor , its working principle, performance, design, construction, advantages and disadvantages and major applications.
Induction motor construction Figure.
A linear induction motor LIM is an alternating current AC , asynchronous linear motor that works by the same general principles as other induction motors but is typically designed to directly produce motion in a straight line. Characteristically, linear induction motors have a finite primary or secondary length, which generates end-effects, whereas a conventional induction motor is arranged in an endless loop. Despite their name, not all linear induction motors produce linear motion; some linear induction motors are employed for generating rotations of large diameters where the use of a continuous primary would be very expensive. As with rotary motors, linear motors frequently run on a three-phase power supply and can support very high speeds. However, there are end-effects that reduce the motor's force, and it is often not possible to fit a gearbox to trade off force and speed.
Наконец-то. ГЛАВА 77 Стратмор остановился на площадке у своего кабинета, держа перед собой пистолет. Сьюзан шла следом за ним, размышляя, по-прежнему ли Хейл прячется в Третьем узле. Свет от монитора Стратмора отбрасывал на них жутковатую тень. Сьюзан старалась держаться поближе к шефу на небольшой платформе с металлическими поручнями. По мере того как они удалялись от двери, свет становился все более тусклым, и вскоре они оказались в полной темноте.
- Подождите. Я же просил меня подбросить. ГЛАВА 59 Сьюзан протянула руку, и коммандер Стратмор помог ей подняться по лестнице в помещение шифровалки. А перед глазами у нее стоял образ Фила Чатрукьяна, его искалеченного и обгоревшего тела, распростертого на генераторах, а из головы не выходила мысль о Хейле, притаившемся в лабиринтах шифровалки.
Решайте! - крикнул Хейл и потащил Сьюзан к лестнице. Стратмор его не слушал. Если спасение Сьюзан равнозначно крушению его планов, то так тому и быть: потерять ее значило потерять все, а такую цену он отказывался платить. Хейл заломил руку Сьюзан за спину, и голова ее наклонилась. - Даю вам последний шанс, приятель.
Сьюзан ни слова не сказала об истинной причине своей беседы с Дэвидом Беккером - о том, что она собиралась предложить ему место в Отделе азиатской криптографии. Судя по той увлеченности, с которой молодой профессор говорил о преподавательской работе, из университета он не уйдет. Сьюзан решила не заводить деловых разговоров, чтобы не портить настроение ни ему ни. Она снова почувствовала себя школьницей. Это чувство было очень приятно, ничто не должно было его омрачить.
Он, конечно, с легкостью мог набрать код лифта и отправить Сьюзан домой, но она нужна ему .
PDF This paper explores the construction process of a linear induction motor LIM , the basic concepts behind key aspects of linear induction machines construction and the testing process of a working prototype.Mismuleti1984 06.05.2021 at 13:48
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The basic design and construction of a linear induction motor is similar to a three phase induction motor, although it does not look like a.