Accelerations of up to 1 g with speeds in excess of 1800 inches per second 45 ms are possible with lims. It also illustrates the usage of dedicated motor control libraries that are included in the sdk. Pdf speed control of linear induction motor using sliding. 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 induction. A theoretical background on scalar motor control principle.
One component defines the magnetic flux of the motor, the other the torque. The stator generally consists of a multi phase winding in a laminated iron core. Introduction 1linear induction motor lim is widely used in places that requires linear motion since it produces thrust directly and has simple structure, easy maintenance and low cost. A linear induction motor lim is an alternating current ac, asynchronous linear motor that. A linear motor is an electric motor that has had its stator and rotor unrolled thus instead of producing a torque it produces a linear force along its length. Then, equation 1 can be shown in terms of magnitude as. Model predictive control of linear induction motor drive. Of course, this would introduce extra control problems, but it also.
Simplified theory of doublesided linear induction motor with. By using variable frequency control, it is possible to adjust the speed of the motor either above or below base speed. Thus the leakage reactance of the linear motor is decreased and. An induction motors rotor can be either wound type or squirrelcage. Characteristically, linear induction motors have a finite primary or secondary length, which generates endeffects. In this post let us see what are the various methods to control the speed of induction motor. The advent of vector control techniques has solved induction motor control problems. A properly designed variable frequency inductionmotor drive can be very flexible. Linear induction motors lims are used to control the propulsion of maglev transportation and carrier system. It is widely used in industry due to low cost and rugged construction. Rotor resistance control of induction motor electrical4u. 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.
This paper deals with the indirect vector control of linear induction motor lim in order to control the speed and thrust output of the linear induction motor drive. An induction motor or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. Line voltage control the torque developed varies with the square of the applied voltage. The speed control of induction motor is done at the price of reduce in efficiency and low power factor. Modeling of linear induction machines for analysis and control institution. For singlesided assemblies, the reaction plate consists of 18in. This thesis considers robust control of an induction motor drive, consisting of an input filter, a voltage source inverter and one or several induction motors in parallel. 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. I would just like to add some practical applications of lim.
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. A theoretical background for the induction motor input current variation due to variation in speed is presented and the theoretical result is compared with the experimental observations, when the motor speed is varied by variation of input voltage. Speed control of linear induction motor using sliding mode controller considering the end effects article pdf available in journal of electrical. Induction motors are the most widely used motors for appliances, industrial control, and automation. However, linear motors are not necessarily straight. The article deals with linear induction motor lim with a squirrelcage. Several control techniques have been used to control the speed andor position of induction motor drives. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. A three phase induction motor is mostly a constant speed motor so its fairly not easy to control its speed. If the motor slip is known, the rotor speed can be expressed by the equation. Design of high speed induction motors linear induction motors. Speed control of induction motor using cycloconverter. Introduction linear electric motors lems belong to the group of special electrical machines. Index termslinear induction motor, equivalent circuit parameters, finite element method, vector control, material of reaction plate i.
Simultaneous propulsion and levitation control of linear. A six thyristor balaced ciruit is proposed for speed control and its performance is compared with that of sine wave variac voltage control. 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. Thrust control of traction linear induction motors in switch. In the present work, the simulation of speed control of motor at different. The application serves as an example of ac induction vector control drive design using a motorola dsp with sdk support. In this type of motor, the stator and rotor are called primary and secondary respectively. Induction motor seminar ppt, pdf report study mafia. Ultrahigh frequency effects of power electronics tests on induction machines. Comparison of different motor control principles using. Speed control of linear induction motor using sliding mode controller considering the end effects article pdf available in journal of electrical engineering and technology 71. Electric motor electric motor linear induction motors.
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. 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. 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 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 single phase induction motor using triac. Optimalairgap control of a linear induction motor for korean.
Synchronous speed of an induction motor is shown in equation 1. Speed control of an induction motor there is a various method of speed control of an induction motor. Performance optimization of linear induction motor by eddy current 771 journal of engineering science and technology december 2011, vol. Effect of varying rotor resistance by adding external resistance to wound rotor motor speed control by variable frequency vfd. Speed control of vector controlled induction motors using.
From the equation 1 it is clear that the motor speed can be changed by a change in frequency f, a number of poles p, and slip s. The result is a flat stator, or upper section, of iron laminations. Speed tracking of a linear induction motor enumerative. Chapter 3 induction motor and different speed control methods page no 3.
An843, speed control of 3phase induction motor using. The characteristics of typical low speed linear induction motors are considerably different to the characteristics of typical squirrel cage induction motors. However, induction motors do not inherently have the capability of variable speed of operation. Speed control kit for induction motors jaycar electronics. The magnetic field now sweeps across the flat motor face instead of rotating. They can be used in control of motors used in conveyors and other machinery. Speed control of 3phase induction motor using pic18 microcontrollers. The main goal of this controller is to provide the optimal 3phase primary voltages necessary fo r tracking a certain speed reference trajectory.
By matt johnson, industrial devices corp basically, linear induction motors are little more than a cut open and rolled flat version of rotary ac induction motors. Before discussing the methods to control the speed of three phase induction motor one should know the necessary formulas of speed. In this control method, it is possible to apply the conventional vector control to the thrust force control of lim. We know that t he speed of the induction motor is given by, from the above equation, the speed of the motor can be controlled by changing supply frequency and by changing number of poles in the stator. Speed control of a three phase induction motor using pwm. What is a linear induction motor and how does it work. P417 bechar 08000, algeria 2university of sciences and technology of oran, algeria abstract in this paper, an adaptive backstepping control system with a fuzzy integral action is. 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. 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. Request pdf speed control of doublesided linear induction motors for automated manufacturing systems the doublesided linear induction motor dlim is acquiring a significant relevance in the. Speed of a dc shunt motor can be varied very easily with good efficiency, but in case of induction motors, speed reduction is accompanied by a corresponding loss of efficiency and poor power factor. This paper present the speed control of single phase induction motor using arduino with the controlling objectives pwm and spwm.
The speed control of poly phase induction motor can be done through the different methods. Nonlinear control for linear induction motor servo drive. Numerous applications of lims can be found in industry today, one of the most interesting being high speed magnetic levitation railway systems. Previously, to control the relative speed of the primary and secondary members of a linear induction motor it has been necessary to control the supply of current to the primary member using complex and expensive electronic circuitry. Linear induction motor motion control h2w technologies. The performance of the proposed dtfc method is analyzed with considering endeffect.
Speed control of threephase induction motor by stator. Vivek brahmbhatt already has explained very nicely the construction of lim. Among these control techniques, the method of direct torque control dtc is considered one of the most efficient as techniques that can beused for induction motors, 9. Force engineering ltd linear induction motor control. Mover position control of linear induction motor drive using adaptive backstepping controller with integral action i. Main applications of these machines are in high speed ground transportation, sliding doors, flexible manufacturing systems, robotic systems, etc. 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. Characteristically, linear induction motors have a finite primary or secondary length, which generates endeffects, whereas a conventional induction motor. Abstract this paper presents a novel sensorless second order sliding mode control sosmc scheme for linear induction motor lim.
Fuzzy logic control of linear induction motor emre ozkop adem sefa akp. Direct current that excites magnetic field in dc generator is set so that, when rated speed is reached, electrical power amounts 4 kw. Figure 2 represents the configuration of a sp type linear induction motor. Introduction linear induction motor has been applied in urban transportation system widely, mainly because of its low. Nowadays, linear induction motors lims are widely used in a variety of applications like transportation, conveyor. Force engineering ltd how linear induction motors work. The speed control of induction motor is done at the cost of decrease in efficiency and low electrical power factor. Applications may require very precise speed or positional control, despite wide variations in vehicle total mass. Furthermore, the constant thrust control in switch areas is analyzed and the future research work is discussed. It has problem that the controls of the lim and of the levitation magnets interfere each other because the attractive. The normal operating region for the induction motor is the nearly linear portion between rated speed and synchronous speed, shown by the heavy line. Pdf adaptive backstepping controller design for linear. Simplified steadystateequivalent circuit of induction motor. Characteristics of linear induction motor considering.
An induction motor can be used as induction generator, or it can be unrolled to form the linear induction motor which can directly generate linear motion. An induction motor can therefore be made without electrical connections to the rotor. Speed tra cking of a linear induction motor enumerative. Generally, induction motors are categorized based on the number of stator windings. The most commonly used controller for the speed control of. So speed control of this motor is an important agenda.
Pdf fuzzy logic control of linear induction motor emre ozkop. Here we will discuss about the speed control of wound rotor induction motor using variation of rotor resistance. The linear induction motor is similar in construction to a circular motor that has been opened out flat. The rotor speed of an induction motor is given by the equation shown below. These differences must be taken into account when choosing a control system. Induction motors are widely used electrical motors due to their reliability, low cost and robustness. Speed control of doublesided linear induction motors for. 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. 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. Free download induction motor seminar ppt, pdf report.
In the usual maglev transportation system using lim, the levitation of the carrier are controlled by the levitation magnets. Speed control induction motor pdf 8 speed control of induction machines. Various induction motor speed control methods advantages. Control of traction and levitation of linear induction. Nov 11, 2011 the linear induction motor is designed for high speed operation. Pdf programmable logic control based simultaneous speed. Jan 09, 2017 speed control methods of induction motor. Figure 3 shows the relation between the voltage and. Normally lim is used to make a motion frictionless absolutely. In this paper, we propose the novel control method of the thrust force and the attractive force of lim driven by the power source with the frequency component synchronous with the motor speed.
The user can quickly start evaluating the performance of the vhz system with this method. Second order sliding mode control with mars speed estimation of. Singlesided induction motor slims are used more because of their simple structure. Moreover, constraints over the flux and current could be imposed to keep them within permissible values. An induction motor is practically a constant speed motor, that means, for the entire loading range, change in speed of the motor is quite small. 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. Adjustable squirrelcage linear induction motor for magnetic. Energy harvesting with single sided linear induction machines featuring secondary conductive coating pdf. The simulation of speed control and thrust control is conducted to verify thecontrol syst em. The invention relates to a speed control system for a linear induction motor. 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. The basic characteristic of dtc is that the positions of the. The reference speed value for motor acceleration is linear ramp. P417 bechar 08000, algeria 2university of sciences and technology of oran, algeria abstract in this paper, an adaptive backstepping control system.
Characteristically, a linear motor s active section has ends, whereas more conventional motors are arranged as a continuous loop. A three phase induction motor is basically a constant speed motor so its somewhat difficult to control its speed. 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. The simplest linear motor is the singlesided linear induction motor lim, which consists of a primary coil assembly and a secondary formed by a reaction plate. Speed control of induction motor 7 ways to control induction. Thrust analysis and improvement of single sided linear. In this system, the scalar control vhz of induction motor experiments with and explores the use of speed control. Jun 30, 2015 a three phase induction motor is basically a constant speed motor. A linear induction motor provides linear force and motion rather than rotational torque. This makes constant vf the most common speed control of an induction motor. Figure 27 illustrates the peak magnitude of flux density in the. The linear induction motor is designed for high speed operation.
Mover position control of linear induction motor drive. Linear induction motor, end effects, dolphin effect, finite element method, mosebach model, thrust. This paper presents a field oriented control scheme of the linear induction motor lim in order to achieve high performance of the machine. Indirect vector control of a redundant linear induction motor.
The role of cycloconverter in speed control of induction motor is to vary the supply frequency which in turn, changes the speed of motor. In ac rotating machine speed of machine is govern by the equation n120fp. Even though the operating principle is exactly the same as a rotary motor, the linear motor has a finite length of the primary or secondary parts and it causes static and dynamic endeffect which is the discontinuous airgap flux phenomenon. Performance analysis of the linear induction motor for the deepunderground highspeed gtx 202 maximum speed should be around 34. If the induction motor is operating in the linear magnetic region, the lm is constant. Lim is an advanced version of rotary induction motor which gives a linear translational motion instead of. Thus it is obvious that to change speed of machine any one parameter either frequency or no of poles are to be changed. Approaches of vector control of a linear induction motor. Full form kit includes case, doublesided silkscreened pcb, heatsink, cooling fan, hardware and electronics including parts from revised article in august 20. The motor torque is here controlled by using the method indirect self control isc, and power oscillations between the inverter and the input filter. A linear induction motor lim is a specific type of alternating current ac, multiplephase machine that provides force and movement in a linear direction. The flat ac linear induction motor lim is typically run directly off of 3 phase line voltage, with an adjustable frequency, or vector drive if speed control is required.
Induction motor is configured in delta connection, with dc generator as load 6. They contain no permanent magnets, so there are no attractive forces between motor components when power is removed from the system. Linear induction motors can be manufactured in a wide range of force outputs, speeds, and footprints. Speed control of induction motor 7 ways to control. This study proposes a speed estimation scheme for the sensorlessvectorcontrolled linear induction motor lim drives for mediumlow speed maglev applications, which is composed of two parts.
Simulation results have shown the algorithm had good performances. Two types of the motor are found, singlesided and doublesided. 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. Speed control of three phase induction motor electrical4u. Selection of linear motor topology both linear permanent magnet synchronous motors lpmsms and linear induction motors lims have been manuscript received july 3, 2008. The secondary of a slim consists of conducting plate backed by a ferromagnetic. An843, speed control of 3phase induction motor using pic18 mcus. Performance analysis of the linear induction motor for the. Jun 08, 2019 nearly 80% of the worlds ac motors are poly phase induction motors. A linear induction motor lim is a specific type of alternating current ac motor designed to produce motion in a straight line. 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. Why is speed control in an induction motor, difficult. For many induction motors, the average torque drops a bit as it accelerates and then rises to a peak value of torque, known as the pullout or breakdown torque. They are capable of speeds up to 1800 insec 45 ms and are typically used in applications where accurate positioning is not required.
452 622 1397 1396 846 847 1019 645 292 616 167 90 165 898 634 1319 419 1093 1385 832 726 636 1287 448 461 803 266 1381 1069 604 972 4 220 80 1096 647 895 468 201 1458 594 951