Pdf fuzzy logic control of linear induction motor emre. An induction motor can be defined as the ac electric motor device in which a power source fed by the alternating current with the help of a primary winding. Simulation results have shown fem was a good method, but little test results exited. Linear induction motors are quite an engineering marvel, to convert a general motor for a special purpose with more or less similar working. This paper presents fuzzy logic control for a singlesided linear induction motor slim. A linear induction motor lim is a noncontacting, high speed, linear motor that operates on the same principal as a rotary, squirrel cage, induction motor. Ppt linear induction motor powerpoint presentation. Advantages and disadvantages of induction motor electrical4u. Pdf construction of three phase linear induction motor. In an induction motor, the electric current in the rotor needed to produce torque is obtained via electromagnetic induction from the rotating magnetic field of the stator winding. The induction motor is made up of the stator, or stationary windings, and the rotor. Zimmerman pulsed power sciences center sandia national laboratories, albuquerque, nm 87 185 abstract the seraphim segmented rail phased induction motor concept is a linear induction.
He built several models in the lab, and designed on paper a coilgun for a trip to the moon. Fuzzy logic control of linear induction motor emre ozkop adem sefa akp. Take a conventional rotary servo motor and unwrap it. Discusses constructions of linear electric motors and drives, areas of theoretical investigation and problems of practical application. Linear induction motors are suitable for applications that require rapid movement of large payloads. Linear induction motors can achieve speeds in excess of 1800 per second 45 ms and accelerations in the range of 34g. The linear motor training system is a useful teaching tool for instructors who wish to demonstrate the basic principles of magnetism as applied to the operation of linear induction motors. This is the basic linear induction motor working principle. Equivalent circuit of induction motor with rotatingtravelling magnetic field.
However, a slip ring is required to feed dc supply to the rotor in the case of a synchronous generator. Linear motors are electric induction motors that produce motion in a straight line rather than rotational motion. Here are the design notes from a welldocumented lim coilgun in 1937. A linear induction motor lim is a specific type of alternating current ac motor designed to produce motion in a straight line. Each primary is installed along the entire length of the launch structure, but is divided into sections. The rotor will constantly be turning to align its magnetic field with that of the stator field. Sizes vary from fractional horsepower to several thousand horsepower used for such applications as dieselelectric locomotives. Pdf the equipment and data acquisition system for testing linear induction motors lims has been described. The shape and operation of a linear induction motor can be visualized as depicted in the figure by making a radial cut in a rotating induction machine and flattening it out. Linear motors complement todays linear motion technologies. They may be obtained by cutting and unrolling the rotary induction machines to yield flat, singlesided topologies figure 5a, where the cage secondary may be used as such or replaced by. Linear induction motors are less efficient than permanent magnet linear motors, and thus produce more heat for a given continuous force output. Being a leader in linear motor design and manufacturing, baldor continually develops advanced products and innovations to meet a variety of linear motion applications. In this type of motor, the stator and rotor are called primary and secondary respectively.
Innovia metro stylized as innovia metro is the current name given to an automated rapid transit system manufactured by bombardier transportation. The rated single or 3phase ac voltage is applied to the linear induction motor. How an induction motor works by equations and physics. The basic idea of an electric motor is to generate two magnetic fields. Vivek brahmbhatt already has explained very nicely the construction of lim. Mec design and construction of a pulsed linear induction motor. In the last years, in the field of research on linear induction drives, a lot of efforts have been oriented to improve the dynamics performances of these.
Free download induction motor seminar ppt, pdf report. The technology is not new but merely designed in a. The method is very accurate and often has been used for validating the fem computer software. Stator poles rotate at the synchronous speed ns when fed with a three phase supply.
More in detail, from a doublesided linear induction motor. The linear induction motor science publishing group. American journal of electrical power and energy systems. The linear induction motor is designed for high speed operation. The premier electrothermic engineer and father of the induction heating industry, edwin finch northrup, foresaw the application of induction motor design to coilguns. Singlephase induction motor threephase induction motor singlephase induction motor there are probably more singlephase ac induction motors in use today than the total of all the other types put together. A linear induction motor has a polyphase energizing winding formed of groups of generally flat bobbintype windings arranged in two or more winding layers, the windings in each winding layer being generally coplanar with one another. An induction motor is based on the principle of induction of voltages and currents. The most important advantage of an induction motor is that its construction is quite simple in nature. As a result, they often require forced air or watercooling to achieve published specifications. It utilizes the method of fourier transform for developing closed form solution.
Generally, induction motors are categorized based on the number of stator windings. Ac induction motor high performance linear induction motor baldor provides industry with the widest range of linear motors, linear stages and controls. So now what was the stator is now a forcer and the rotor becomes a coil or magnet rail. If a rotary induction motor is compared with the linear induction motor, the lim requires a larger air gap and hence, the magnetising current is greater and the power factor and efficiency of the motor are lower. The lims 3phase coil assembly can be directly connected to the ac line for single speed applications or to an adjustable frequency drive for variable speed control. Basically a special purpose motor that is in use to achieve rectilinear motion rather than rotational motion as in the case of conventional motors. In a conventional round rotor induction motor the behavior of the machine is only needed to be calculated ov er one pole pi tch. Innovia metro systems run on conventional metal rails and pull power from a third rail, but are powered by a linear induction motor that provides traction by pulling on a fourth rail placed between the running rails. Normally lim is used to make a motion frictionless absolutely. Singlesided linear induction motors slim 1 3 are electromagnetic devices of directly converting electrical energy into mechanical energy to realize linear motion without any mechanical converters, which have been applied in various industries. Making use of three phase systems, fundamental devices are used to produce.
The principle of the linear induction motor can be easily under. Dec 04, 2018 how does an induction motor work how it works 3 phase motor ac motor duration. A linear induction motor or lim is a special type of induction motor used to achieve rectilinear motion rather than rotational motion as in the case of conventional motors. One, two, and threedimensional solutions of the field equations have been obtained along with numerical solutions for the electromagnetic field in. The generating mode for induction motors is complicated by the need to excite the rotor, which begins with only residual magnetization. Linear induction motor working principle your electrical guide. Introduction linear induction motor lim, is basically an advanced version of motor that is in use to achieve rectilinear motion instead of rotational motion as in ordinary conventional motors. The result is a flat stator, or upper section, of iron laminations. Each aircored linear induction motor has a primary winding consisting of a linear array of coaxial circular coils, and a secondary which is a cylindrical conductive sleeve concentric with the primary. A linear induction motor lim is an advanced version of rotary induction motor which gives a linear translational motion instead of the rotational motion.
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. Like permanent magnet linear motors commonly designated as ironless and iron core types linear induction motors consist of a primary part analogous to the stator in a rotary induction motor and a secondary part analogous to the rotor in a rotary version. A linear induction motor provides linear force and motion rather than rotational torque. Ac voltage controllers are used as soft starters for smooth starting of induction motors. Characteristics of linear induction motor considering. Pdf experimental tests on linear induction motors researchgate. Instead of producing rotary torque from a cylindrical machine it produces linear force from a flat one. This book is a report on the results of particular research activities and is not intended as a comprehensive reference work. A lim operates under the same principles as its ac rotary motor counterpart, typically powered by a threephase voltage scheme with a.
Theory of linear induction motors by sakae yamamura. 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. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. This is quite an engineering marvel, to convert a general motor for a special purpose with more or.
It can also be used by students for determining the basic electrical characteristics of a linear induction motor and studying the dynamic behavior tractive force, acceleration, top speed of a linear. If done so, the rotor poles get magnetically coupled with the rotating stator poles, and thus the rotor starts rotating at the synchronous speed. Reasons are the same that are in the case of a cylindrical induction motor. Induction motors are the commonest type of motor and account for a very large proportion of heavy duty motors. Pdf fuzzy logic control of linear induction motor emre ozkop. In a traditional electric motor, the rotor rotating part spins inside the stator static part in a linear motor, the stator is unwrapped and laid out flat and the rotor moves. The performance of the proposed dtfc method is analyzed with considering endeffect.
Conversion to mechanical power by motors pumps, fans, hvac, refrigeration compressors. Difference between synchronous motor and induction motor. This is one of the best book dealing with the design and analysis of linear induction motor. The complete linear induction motor application tree is illustrated in figure1. What is a linear induction motor and how does it work. A polyphase linear induction motor comprising a primary member having magnetic material formed with a polyphase winding and, for cooperating with the primary member, a secondary member comprising electrically conductive material backed by further magnetic material is so arranged that the working flux passes in low reluctance paths lying substantially in planes directed transversely of the motor. The 3phase set of currents, each of equal magnitude and with a phase. The pulsed linear induction motor university of edinburgh. Linear induction motors are quite an engineering marvel, to convert a general motor for a special purpose with more or less similar working principle, thus enhancing its versatility of. Apr 29, 2018 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.
Design of a single sided linear induction motor slim using a user interactive computer program a thesis presented to the faculty of the graduate school university of missouricolumbia in partial fulfillment of the requirements for the degree master of science by sarveswara prasad bhamidi dr. Standard lims can produce forces in the range of 720lbs 3200n at a 3% duty cycle. Based on vfd settings, a unique voltage and frequency is applied to the linear induction motor. Equivalent circuit of an induction motor enables the performance characteristics which are evaluated for steady state conditions. Soft starters are used for induction motor drives having fan, pump and. The aim this researc h pro ject is to dev elop a linear induction motor system capable of op erating at 400 v olts with an initial energy of 25 j to in v estigate the lo w feasibilit y op erating concept and erify design pro cedure used in. A lim operates under the same principles as its ac rotary motor counterpart, typically powered by a threephase voltage scheme with a force that is produced by a moving magnetic field 1.
Induction motor seminar ppt, pdf report study mafia. The voltage and current is induced in the rotor circuit from the stator circuit for the operation. Characteristically, linear induction motors have a finite primary or secondary length, which generates endeffects. With this design, the load is connected directly to the motor. The rotor of an induction motor can be a squirrel cage rotor or wound. The linear induction motor is one of the most promising propulsion systems for superhighspeed ground transportation. The pulsed linear induction motor concept for highspeed trains b. Baldor linear motors and stages steven engineering. Linear induction motor background alternating current ac electric motor powered by a three phase voltage scheme force and motion are produced by a linearly moving magnetic field used in industry for linear motion and to turn large diameter wheels 6 4.
Induction motors with rotor helical motion 253 difference is in the rotor slip, which for rotary linear motor depends on both rotary and linear rotor speeds. 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. The lim operator shall consist of a control unit, one or more linear induction motors and reaction fin sections. In general, the induction motor is cheaper and easier to maintain compared to other alternatives. The rotor takes the form of a moving platform known as the secondary. In this paper the speed control method of lim, which lead to optimal control characteristic of motor such as thrust, flux and current, is proposed.
May 31, 2019 a linear induction motor or lim is a special type of induction motor used to achieve rectilinear motion rather than rotational motion as in the case of conventional motors. Pdf this paper explores the construction process of a linear induction motor lim, the basic concepts behind key aspects of linear induction machines. In this thesis, the analysis of the dynamic response of a linear induction motor as an electromechanical system is done, accounting for all the governing equations implied in the process which are used to develop the corresponding simulation models. A linear induction motor is a type of linear motor based on a rotary ac induction motor. Similarly to the conventional rotary motors, the secondary resistance can be split into two.
Such an induction motor with integrated brake is shown on figure 1. How an induction motor works by equations and physics introduction. May 22, 2017 used in many industrial and hightech fabrication applications, linear motors are an invaluable part for the fastest and most efficient processes. Each winding group is formed of two or more of the windings one within the other. Bombardier transportation is a world leader in applying linear induction motor lim technology to urban transit systems. I would just like to add some practical applications of lim.
Linear induction motors are quite an engineering marvel, to convert a general motor for a special purpose with more or less similar working principle, thus enhancing its. Nov 11, 2011 the linear induction motor is designed for high speed operation. 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. Linear induction motor induction launc hers feasible within the scop e of a small undergraduate pro ject. Theory of linear induction motors 2nd edition nasaads. In the rotary induction motor the stator and the rotor area are same whereas in the lim the one of the two is shorter than the other. The linear induction motor will start from zero speed and accelerate to the rated velocity based on frequency and mechanical load. Linear induction motors fall into the category of special electrical machines in which the electric energy is converted directly into mechanical energy of translatory. The rotor needs to be rotated at a speed near to the synchronous speed during starting. Jul 15, 2019 a linear motor is effectively an ac induction motor that has been cut open and unwrapped. Linear induction motor a linear induction motor lim is an advanced version of rotary induction motor which gives a linear translational motion instead of the rotational motion. Like cylindrical induction motor, lim also runs at speed less than synchronous speed. The rated single or 3phase ac voltage is applied to the vfd.
In traditional designs of 60 hz linefed induction machines, skin effect is represented by correction coefficients k r and k x for bar resistance and slot leakage inductance. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Characteristically, linear induction motors have a finite primary or secondary length, which generates endeffects, whereas a conventional induction motor is arranged. The construction of the stator is similar in both synchronous motors as well as induction motors. Power lab project application of three phase linear induction motor duration. Electric motor electric motor linear induction motors. The development of the technology started in 1975 and resulted in the implementation of five transit systems with the lim on board with a. Please practice handwashing and social distancing, and check out our resources for adapting to these times.
An induction motor can be used as an induction generator, or it can be unrolled to form a linear induction motor which can directly generate linear motion. Nov 03, 2019 an induction motor also known as an asynchronous motor is a commonly used ac electric motor. Pdf linear induction motor at present time semantic scholar. They are capable of speeds up to 1800 insec 45 ms and are typically used in applications where accurate positioning is not required.
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