Main applications of these machines are in highspeed ground transportation, sliding doors, flexible manufacturing systems, robotic systems, etc. Linear motors lm enable linear movements at high speeds with great accuracy. The objective of this work is to control the position of a field oriented induction motor for a given reference input signal. They are available in a wide range of power ratings. Therefore, by varying the voltage and frequency by the same ratio, flux and hence, the torque can be kept constant throughout the speed range. In general, the induction motor is cheaper and easier to maintain compared to other alternatives. Speed control of fstp inverter fed induction motor drive. Abstract today induction motor requires a variable speed control to serve wide range of applications. The linear induction motor is designed for high speed operation. Characteristics of linear induction motor considering. The value of s for a medium sized motor may vary from 1 on no load to 3% on full load. Normally lim is used to make a motion frictionless absolutely. The achieving of variable speed of an induction motor drive is a challenging task because of non linear behavior of the motor speed.
Pdf this paper proposes a novel robust adaptive speed position tracking. The induction motor is therefore a machine of substantially constant speed. Furthermore, the constant thrust control in switch areas is analyzed and the future research work is discussed. An innovative workbench for dynamic tests was developed to measure the parameters of interest. The induction motor is made up of the stator, or stationary windings, and the rotor. Power electronics and motion control conference ipemcecce. Analysis, design and control aspects of linear machines. Asynchronous motors are the most widely used electrical motors due to their reliability, low cost, ruggedness and robustness.
Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Abstract control of induction motor im is well known to be difficult owing to the fact the mathematical models of im are highly nonlinear and time variant. Curren t w a v eforms pro duced b y the system in practice and theoretical sim ulation are compared to eac h other, in addition qualitativ ely observing an y motion of the armature coil. Linear parameter varying control of induction motors. Hence, the synchronous speed changes with change in supply frequency. However,that constitutes a theoretical challenge, knowing that the model of the induction motor is. Due to this reason, earlier dc motors were applied in most of the electrical drives. The current equations of the induction motor have a particular structure, which allows them to be written on a complex form. For the same reason as in the case of an induction motor, the secondary or runner cannot catch the speed of the magnetic field.
High speeds, the maximum speed of a linear motor is limited only by the bus voltage and the speed of the control electronics. I would just like to add some practical applications of lim. Mec design and construction of a pulsed linear induction motor. However, asynchronous motors do not inherently have the capability of variable speed operation. Ac induction motor speed torque characteristic squirrelcage ac induction motors are popular for their simple construction, low cost per horsepower and low maintenance they contain no brushes, as do dc motors. It can control the speed of an induction motor over a range from as little as 5% of base speed up to about twice base speed. Induction motor seminar ppt, pdf report study mafia.
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. Linear induction motor motion control h2w technologies. The achieving of variable speed of an induction motor drive is a challenging task because of nonlinear behavior of the motor speed. How an induction motor works by equations and physics. The following equations are important in determining the power from the panel 8. Thrust control of traction linear induction motors in. Request pdf speed control of linear induction motor with thrust and stator flux ripple. Simulation results have shown the algorithm had good performances. Main applications of these machines are in highspeed ground transportation. The pulsed linear induction motor university of edinburgh. In 2, an equivalentcircuit model for a highspeed industrial transportation. Jun 30, 2015 a three phase induction motor is basically a constant speed motor.
Multiple simultaneous specifications control highspeed ac. Therefore the efficiency of three phase induction motor is reduced by this method of speed control. 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. Speed control of induction motor using pushpull converter and three phase svpwm inverter dr. Ceitec central european institute of technology, brno university of technology, purkynova 123, brno, czech republic email. Constant cooling by integrated forced ventilation independent of motor speed provides high continuous torque capability at low speed in servodrive applications machine tools. But the recent developments in speed control methods of the asynchronous motor have led. Induction motor equations engn1931f spring 2017 2 let. This means that there is no need for slip rings and brushes. By varying the frequency, the speed of the motor can be varied. What is a linear induction motor and how does it work.
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 conventional induction motor. Main applications of these machines are in high speed ground transportation, sliding doors, flexible manufacturing systems, robotic systems, etc. Synchronous speed of the rotating magnetic field of an induction motor is given by, where, f frequency of the supply and p number of stator poles. Closed loop vf speed control method the basis of constant vf speed control of induction motor is to apply a variable magnitude and variable frequency voltage to the 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. A properly designed variable frequency induction motor drive can be very flexible. This paper presents a field oriented control scheme of the linear induction motor lim in order to achieve high performance of the machine.
This slip power loss can be recovered and supplied back to improve the overall. This work addresses the design of a speed control scheme based on total slidingmode control tsmc theory for a. In order to overcome this, a new method was developed is known as artificial neural network. This method is applicable to squirrel cage induction motor only. A linear induction motor lim is a specific type of alternating current ac, multiplephase machine that provides force and movement in a linear direction. This is used for nonlinear control system because of its ability of modeling a non. Analytical equations and finite element methods fem are used. In the present paper, the mover speed control of a linear induction motor lim using a sliding mode control design is proposed, considering the end effects. Linear motors complement todays linear motion technologies. Introduction linear induction motor has been applied in urban transportation system widely, mainly because of its low. Characteristically, linear induction motors have a finite primary or secondary length, which generates endeffects. Barwell, application of linear induc tion motors to highspeed transport systems, proc. Sliding mode speed regulation of linear induction motors based on direct thrust control with. The most commonly used controller for the speed control of.
The team is proposing to control the speed of the simulated linear track under magnetic levitation conditions. Numerous applications of lims can be found in industry today, one of the most interesting being high speed magnetic levitation railway systems. Efficiency of the lim under varying air gap size and motor speed. An843, speed control of 3phase induction motor using. The speed of induction motor can be varied by changing supply voltage. A three phase induction motor is basically a constant speed motor. Pdf fuzzy logic control of linear induction motor emre ozkop. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. The pulsed linear induction motor concept for highspeed trains b. Performance analysis of the linear induction motor for the. For a 4 pole, 50 hz induction motor, the variation in speed from noload to full load could be 1485 to 1455 rpm.
Chapter 3 induction motor and different speed control methods page no 3. By using variable frequency control, it is possible to adjust the speed of the motor either above or below base speed. Jan 09, 2017 this method is applicable to squirrel cage induction motor only. Actual speed of an induction motor is given as n ns 1 s. Typical speeds for linear motors are 3 meters per second with 1 micron resolution and over 5 meters per second, 200ips, with coarser resolution. Pdf robust adaptive control of linear induction motors with. Speed control of induction motor 7 ways to control. Torquespeed characteristics of a 3oim with constant vf ratio. Abstract direct torque control is considered one of theas most efficient techniques for speed andor position tracking control of induction motor drives. Speed tracking of a linear induction motorenumerative nonlinear model predictive control jean thomas and anders hansson linkoping university post print n. An843, speed control of 3phase induction motor using pic18 mcus. Optimalairgap control of a linear induction motor for korean railway transit 1h.
Performance analysis of the linear induction motor for the deepunderground highspeed gtx 202 maximum speed should be around 34. Linear induction motors canbe considered as the rotary induction motor sectioned axially and. Vivek brahmbhatt already has explained very nicely the construction of lim. In this type of motor, the stator and rotor are called primary and secondary respectively. Speed tracking of a linear induction motorenumerative. The performance abilities of the motor will be tested in the department of electrical and computer.
The proposed solution for the normal force issue consists of a linear induction motor lim optimized for urban sml vehicles. This slip must be present, even when operating in a fieldoriented control regime. Modeling of linear induction machines for analysis and control institution. Design, construct, and test a linear induction motor lim powered by a threephase voltage input rotate a simulated linear track and cannot exceed 1,200 rpm monitor speed, output power, and input frequency controllable output speed 7 5. 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. S l r the flux in the singleturn coil on the rotor surface is.
Induction and synchronous machines differ in the way secondary is excited. Control of induction motors by using programmable logic. Free download induction motor seminar ppt, pdf report. Department of control and instrumentation, faculty. Figure 3 shows the relation between the voltage and. However, induction motors do not inherently have the capability of variable speed of operation. 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. Induction motors are widely used electrical motors due to their reliability, low cost and robustness. The rotor in an induction motor is not externally excited. The small blower motor is an induction machine that runs continuously, thereby allowing the main motor to maintain full torque at low speed without overheating.
Most linear motors are used in the machine construction industry and for production automation purposes. In this leaflet the following information can be found. Ac induction motor speedtorque characteristic squirrelcage ac induction motors are popular for their simple construction, low cost per horsepower and low maintenance they contain no brushes, as do dc motors. Power is nothing without control and whether it is for a roller coaster, a public transportation system or an industrial use, projects that require linear motion often have diverse and in many cases complex control requirements. Introduction linear electric motors lems belong to the group of special electrical machines. The torque developed in this method is proportional to the square of the supply voltage. Moreover when it comes to speed, accuracy and efficiency.
Index termslinear induction motor, equivalent circuit parameters, finite element method, vector control, material of reaction plate i. For singlesided assemblies, the reaction plate consists of 18in. This master thesis is completed at electrical machines and motion control, abb. A linear induction motor lim is an alternating current ac, asynchronous linear motor that. In a linear induction motor lim, the primary inverter is directly controlled by the inverter switching winding corresponds to the stator winding of a rotary states selected using switching table. Linear induction motors can be manufactured in a wide range of force outputs, speeds, and footprints. First, the indirect fieldoriented control lim is derived, considering the end effects. For a slip of s, the speed of the secondary in a linear motor is given by. This is used for non linear control system because of its ability of modeling a non.
With an aim of reducing the cost of the control for the induction motor, several algorithms of estimate of rotor. Electric motor electric motor linear induction motors. However, this control scheme has several drawbacks. This paper present the speed control of single phase induction motor using arduino with the controlling objectives pwm and spwm. The result is a flat stator, or upper section, of iron laminations. Before discussing the methods to control the speed of three phase induction motor one should know the basic formulas of speed and torque of three phase. 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.
The thrust velocity curve of the linear induction motor is similar to that of the speed torque curve of the rotary induction motor. B when citing this work, cite the original article. Sensorless speed non linear control of induction motor. The linear force is given by the equation shown below. This makes constant vf the most common speed control of an induction motor. Control inputs will include the presence of hills, curves, merge areas, and other traffic ahead or behind. It is widely used in industry due to low cost and rugged construction. Vehicle propulsion using continuous track linear induction motors. Speed control of fstp inverter fed induction motor drive with.
Optimalairgap control of a linear induction motor for. A linear induction motor provides linear force and motion rather than rotational torque. Various induction motor speed control methods advantages. A properly designed variable frequency inductionmotor drive can be very flexible. This project examines the use of linear induction motors lims as the primary propulsion. Linear induction machines featuring secondary conductive coating pdf. Speed control of vector controlled induction motors using. Park korea railroad research institute, uiwang, korea1. 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. Exp erimen tal system used to test the pulsed linear induction launc her concept. Where f s is the supply frequency in hz, v s is the velocity of the linear traveling field in meter per second, and t is the linear pole pitch i.
Dongguk university, seoul, korea2 abstract there have been many researches to develop linear induction motors for railway systems for last. It is possible to combine the advantages of matrix. Thrust control of traction linear induction motors in switch. Speed control of three phase induction motor electrical4u. L r s and be the angular velocities of the magnetic field line frequency, rotor, and slip respectively. Photo courtesy of control techniques the main power circuit consists of a sixthyristor bridge circuit as discussed in chapter 2, which rectifies the incoming a. We must observe care a choice of linear k induction motor lim control. Soft starters are used for induction motor drives having fan, pump and blowers types load where load torque is directly proportional to square of speed. Also the implementation of a hardware and software for speed control and protection with the result obtained from the test on induction motor performance is provided and this idea presents a design and implementation of a monitoring and control system for the three phase induction motor based on programmable logic controller plc. The pulsed linear induction motor concept for high speed trains b. Hybrid models combine the benefits of the magnetic equivalent circuit mec method 12. Where s is the slip of the linear induction motor and is given as.
Speed control of linear induction motor with thrust and stator flux. Sensorless field oriented control of 3phase induction. Dec 17, 2019 when the speed control of three phase induction motor is done by adding resistance in rotor circuit, some part of power called, the slip power is lost as i 2 r losses. Force engineering ltd linear induction motor control. The advent of vector control techniques has solved induction motor control problems. A three phase induction motor is basically a constant speed motor so its somewhat difficult to control its speed. Sensorless field oriented control of 3phase induction motors. Motorola 3phase ac induction motor vector control 5 figure 32. Figure 3 short primary double sided linear induction motor. Hence, a dcdc pushpull converter merge with dcac three phase inverter, it is possible.
The change in speed or slip required is normally small. 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. Characteristically, linear induction motors have a finite primary or secondary length, which generates endeffects, whereas a conventional induction motor is arranged. A typical frequency converter with a special induction motor series are shown on figure 1. If we cut the stator of a polyphase induction motor and lay on a flat surface, it forms the primary of the linear induction motor system.
It can control the speed of an induction motor over a range from as little as. Nov 11, 2011 the linear induction motor is designed for high speed operation. Linear electric motors lems belong to the group of special electrical machines. They are capable of speeds up to 1800 insec 45 ms and are typically used in applications where accurate positioning is not required. These effects combine to produce a poor power factor and. Pdf construction of three phase linear induction motor.
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