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