The design template interface for induction motor drive, for example, is shown below. The principle of operation of this motor is based on. In recent years, the control of the induction motor drive is an active research area. Vectorcontrolled induction motor drives the previous control strategies good steadystate but poor dynamic response oscillation resulted from the air gap flux vector control fieldoriented control is related to the phasor control of the rotor flux. Thereby the region above the base frequency is referred to as field weakening, in which the flux decreases as a result of frequency increase, causing the motor torque to decrease gradually. An984, an introduction to ac induction motor control using the. Fall 2005 ee595s electric drive systems 30 overview of strategies voltsperhertz control constant slip control. In very simple words induction motors can be described as a threephase, selfstarting constant speed ac motors. Field weakening strategy for vector controlled induction.
There are essentially two general methods of vector control. Sensorless field oriented control of 3phase induction. Sensorless control of inverterfed induction motor drives. The frequency and amplitude of the drive voltage must be varied to change the motor speed. The most commonly used controller for the speed control of induction motor is traditional proportional plus integral pi controller. The speed of a threephase induction motor driving a given load is determined by matching the torquespeed characteristics of the motor and load, as shown in fig.
In a torquecontrolled induction motor drive, the maximum output torque and output power besides depend on the motor power rating, also depend on the inverter current rating and the maximum voltage that the inverter can supply to the machine. Speed control of induction motor 7 ways to control. Investigation in induction motor starting and speed. Speed control of vector controlled induction motors using. The induction motor drive has many applications like it is used in fans, blowers, mill runout tables, cranes conveyers, traction, etc. The purpose of the scalar control technique is to control the magnitude of the chosen. The typical torque versus speed curve of an ac drive fed induction motor is illustrated below. Today i will discuss very important topic speed control of induction motor. Squirrel cage wound rotor with slip rings the rotating magnetic field the basic idea of an electric motor is to generate two magnetic fields. Induction motor drives starting braking speed control of. Control of an induction motor drive a report is to be written on this assignment in groups of two or alone. In this thesis voltage model is used for the flux estimation.
Record all nameplate information for the induction motor. Speed control of induction motor by variable frequency control variable frequency control is a method which is used to control the speed of an induction motor. The book presents a practical computer simulation model of the induction motor that could be used for studying various induction motor drive operations. Pdf control of induction motor drive using artificial. Rotorflux orientation i d axis of coordinate system is. 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. The induction motor drive is a dynamic nonlinear system with uncertainty in the machine parameters. This 3 phase motor is also called as an asynchronous motor. By utilizing the similarity between the vector controlled induction motor drive and the separately excited dc motor, a method for the design and study of the speed controller for the speedposition drive is formulated. The previous control strategies good steadystate but poor. Vector control, also called fieldoriented control foc, is a variablefrequency drive vfd control method in which the stator currents of a threephase ac.
Before discussing, induction motor drives its important to understand and know about induction motors. Pdf on jul 1, 2015, saroj kumar sahoo and others published field weakening strategy for vector controlled induction motor drive near six step mode of operation find, read and cite all the. A three phase induction motor is basically a constant speed motor so its somewhat difficult to control its speed. Scalar control of induction motor drives using dspace ds1104. This results in the simplicity of the design approach and helps in improving the performance of the drive system. This method needs two motor, one of them is wound motor. In dc separately excited motor, it needs to be control only the magnitude of armature and field currents and in turn, these two parameters are inherently decoupled and a very good dynamic performance is obtained. Pdf design of combined vector control and direct torque. Another control strategy for inverterfed variablespeed drives is the field. The aim of this study is to improve tracking performance of the induction motor drive.
Model predictive control of vector controlled induction. Indirect vector controlled ivc induction motor drives used in high. How does an ac drive control induction motor speed. One called the direct or feedback method, and the other, the indirect or feed forward method. There are four possible speeds can be obtained by this arrangement. In this application note, we will generate a third pwm in software, using a general purpose timer and an io pin resource that are readily available on the picmicro microcontroller. The control system of the drive calculates the corresponding. Calculation of slip energy recovery induction motor drive. The fieldoriented control induction motor drive block represents a standard vector or rotor fieldoriented control drive for induction motors. A dspbased nn control system is built for an ipm motor drives system, and a high. Speed control of induction motor by variable frequency control. The control strategies explored include expertsystembased acceleration control, hybridfuzzypi twostage control, neuralnetworkbased direct self control, and genetic algorithm based.
The content of this book is divided into three basic parts. Various induction motor speed control methods advantages. The speed control loop outputs the reference electromagnetic torque and rotor flux of the machine. Induction motor drive system with vector and field weakening control a motor drive system consists of a dc bus, 3phase voltage source inverter, motor, motor controller, and mechanical load. There are two types of induction motors, one is named as single phase induction motor, while the second one is named as 3 phase induction motor. Pdf this paper develops a neural network nn vector controller for an. Physical layout of induction motor in an induction motor induction refers the field in the rotor is induced by the stator currents and asynchronous refers that the rotor speed is not equal to the stator speed. And the technology has further advances in this field. The proposed nn vector control utilizes the rotor fluxoriented ref. This means that there is no need for slip rings and brushes.
Chapter 3 induction motor and different speed control methods page no 3. Vector control, also called fieldoriented control foc, is a variablefrequency drive vfd control method in which the stator currents of a threephase ac electric motor are identified as two orthogonal components that can be visualized with a vector. The speed control of induction motor is more important to achieve maximum torque and efficiency. Teco totally enclosed fan cooled squirrelcage induction motors are designed, manufactured and tested to meet or exceed the latest nema, ieee, csa and other international standards. So a new concept of vfd variable frequency drive is used for controlling the speed and limiting the starting current of a induction motor with variable load attached to the motor. This slip must be present, even when operating in a fieldoriented control regime. The synchronous speed of an induction motor is given by the relation shown below.
Early acim drives used scr devices connected to the motor as. Torque versus slip speed of an induction motor with constant stator flux both open and closedloopcontrol of the speed of an ac induction motor can be implemented based on. Pdf model predictive control of induction motor drives. Variable speed control of induction motor evolved from scalar control method like vf control to more sophisticated a nd efficient vector control methods as illustrated in figure 12. The induction motor drive is selfstarting, or we can say when the supply is given to the motor, it starts rotating without any external supply. Pdf this paper presents the design of a hybrid fuzzy sliding mode controller for a threephase induction motor controlled by the technique of rotor.
An induction motor is presented as an electromechanical power converter, and basic relations between the electrical, magnetic and mechanical quantities in the motor will be explained. The space vector concept, which is derived from the rotating field of induction motor, is used for modulating the inverter output voltage. Today, it is possible to deal with the axis control of machine drives with variable speed in low. Vector control of induction motor drives springerlink. This fact led the researchers to develop several tacholess vector control schemes for estimating motor speed. Design and implementation of an adjustable speed drive. The two motors are mechanically coupled together to drive a common load. Speed control of induction motor using pi and pid controller.
Sensorless speed and position control of induction motor. The speed control of induction motor is done at the cost of decrease in efficiency and low electrical power factor. Speed control of vector controlled induction motors using integral. The control methods for induction motors can be divided into two parts. The first consists in full control of motor currents. It is a 16 bit highperformance digital signal controller dsc. A novel neural network vector control technique for induction. This process is experimental and the keywords may be updated as the learning algorithm improves. The control performance of field oriented induction motor drive greatly depends on the correct stator flux estimation. Performance of induction motor fieldweakening operation. This paper presents design and analysis of a three phase induction motor drive using igbt. Applied intelligent control of induction motor drives. The synchronous speed and therefore, the speed of the motor can be controlled by varying the supply frequency. Induction machine servo drive system is considered highperformance when the rotor position, rotor speed and stator currents can be controlled to follow a reference for tracking at all times 36.
The aim of the paper deals with investigation on the concept of speed control of a threephase induction motor along with energy saving. You should also make a dc measurement of stator winding linetoline resistance using a dmm. Speed control of three phase induction motor electrical4u. Introduction to induction motor the engineering projects. 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 motor is an ac electric motor, having a stator and a rotor just like other motors, but the working principle is a little different which would be discussed further. The proposed nn vector control utilizes the rotor fluxoriented reference frame, and. One component defines the magnetic flux of the motor, the other the torque. A track is a desired time history of the motor current, speed or position. Pdf the field oriented based vector control foc and the direct torque dtc are.
This drive features closedloop speed control based on the indirect or feedforward vector control method. Systems, methods and devices for vector control of induction. The threephase ac induction motor is a rotating electric machine that is designed to operate on a threephase supply. Scalar control is relatively simple method compared to vector control. Drm092, 3phase ac induction vector control drive with single. Pdf dsp implementation of a neural network vector controller for. The starter of slip ring induction motor is connected to threephase supply and its rotor is connected to stator of the other machine. A variable reference is tracked by the sensorless vector controlled adjustable speed drive asd. Parameters and speed identification of sensorless vector. The reason for describing induction motors as constant speed is because normally these motors have a constant speed depending on the frequency of the supply and the. History of power electronics for motor drives in japan pdf.
An843, speed control of 3phase induction motor using. Sensorless control is considered to be a lower cost alternative than the position or speed encoderbased control of induction motors. Vector control induction motor feed forward control rotor winding induction motor drive these keywords were added by machine and not by the authors. A variablefrequency drive vfd or adjustablefrequency drive afd, variablevoltagevariablefrequency vvvf drive, variable speed drive vsd, ac drive, micro drive or inverter drive is a type of adjustablespeed drive used in electromechanical drive systems to control ac motor speed and torque by.
The ac induction motor is a rotating electric machine designed to operate from a 3phase source of alternating voltage. When the inverter power capability is higher than the machine power, it should be limited to. Two popular sensorless control methods, namely, the model reference adaptive system mras and the luenberger observer lo methods are compared for speed and torque control characteristics. Transformertvoe circuit model for the induction motor 2. The 3phase alternating current ac induction motors are mechanically simple, rugged, highly reliable, lower in cost per horsepower than dc motors and capable of more torque and efficiency than singlephase ac motors. These motors are suitable for all general applications where an open machine is not applicable due to severe environments such as excessive dirt, dust andor moisture. The motor is mounted in a test rig that allows one to control the torque applied to the motor shaft and to measure both rpm and torque. This application note also covers the basics of induction motors and different types of induction motors. The rotor in an induction motor is not externally excited. Sections 4 and 5 show how the conventional ec can be used to calculate the harmonic currents. Request pdf model predictive control of vector controlled induction motor drive this paper presents the application of the model predictive control mpc technique for controlling the speed of. Submit your report as a pdf le to the mycourses portal mycourses. Any control system for highspeed electric drive powering a ha has to meet two fundamental re quirements. The main objective of a sensorless foc in induction motor drive is the.
Permanent magnet synchronous motor is used for medium power drives. Speed control of induction motor using vector control. Conclusion in this paper a design and implementation of voltagefrequency vf control of induction motor im drives. In this modulation technique the three phase quantities can depicted in figure2, and supplies power to the loa.
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