Induction machine basics the motor, used in this thesis work, is a two pole induction machine composed of a cage rotor and a stator containing windings connected to the 3 phase power supply. In repulsion motors the stator windings are connected directly to the ac power supply and the rotor. Three coils are placed on the stator of squirrelcage three phase induction motor which they have phase difference with each other 120 degrees. Mod01 lec17 dynamic equations of induction machines. In this case, power flows from the mechanical system, to the rotor circuit, then across the air gap to the stator circuit and external electrical system. Phasor diagram of induction motor on noload and loaded conditions, visualization of a three phase induction. But producing goods and services is strongly related to the. Nptel video lectures, iit video lectures online, nptel youtube lectures. Fall 2005 ee595s electric drive systems 36 the plan continued achieving 14. In common for induction machines is that the stator is made up of a stack of steel laminations pressed into a aluminum or cast iron frame, and. Three phase is more efficient and economical and is provided to industrial sites for heavyduty equipment with three phase motors. The ac induction motor is the most used electrical motor in industrial applications worldwide. Syllabus of bachelor of technology in electrical engineering 4th semester.
So, this document provides information about single phase induction motor, constructionstator, rotor, working principle, types of single phase induction motors, starting methods of single phase induction motors, and applications of single. As induction motors are widely being used, their speed control may be required in many applications. 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. An induction motor s rotor can be either wound type or squirrelcage type. Oct 05, 2016 hi friends, i hope you all are fine and doing great with your lives. Single phase machines are restricted to small power levels. Apr 18, 2020 ppt three phase induction motor electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. Single phase induction motor the engineering projects. So, it is given that a look at the point a 100 kva 442 220 volt single phase 50. Noload and blocked rotor test on an induction machine. This system avoids the frequently used triac phase angle control drives and provides variable ac voltage during the starting of the single phase induction motor. February 18, 2020 february 24, 2012 by electrical4u. Consequently, a defect can induce high losses in terms of cost and can be dangerous in terms of security and safety.
A 6 pole, 50 hz, three phase induction motor running at 960 rpm on certain load has the rotor copper loss of 5 kw. The 3 phase set of currents, each of equal magnitude and with a phase. Basic electrical technology basic electrical technology. Jan 02, 2017 singlephase induction motor this singlephase motors are truly two phase machines. Lesson 29 rotating magnetic field in three phase induction motor. Historythe induction motor with a wrapped rotor wasinvented by nikola tesla in 1888 in the unitedstates. Mod01 lec20 induction machine in two phase reference frame. You should also make a dc measurement of stator winding linetoline resistance. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain.
If a set of three phase current is added to these three coils, rotating field is created in air gap which rotates with suitable speed with frequency of the applied current. Tech in electrical engineering iase deemed university. This paper presents a new technique for rotor fieldoriented control rfoc of a single phase induction motor im with two asymmetrical main and auxiliary windings. Both types are popular but for larger sizes the induction motor is the most highly. Electrical machines electrical engineering ee gate. Polyphase induction motors electrical engineering questions. Explain the speed control of three phase induction motor by rotor injection method. Dynamic model in space vector form mathematical description of induction motor is based on space vector notation.
List the causes that are responsible for nonstarting of a three phase induction. Three phase, 230 v, 460 v, 575 v or higher, have three wires that supply voltage waveforms, each supply electricity at different times. Noload and blocked rotor test on an induction machine aim. Single phase induction motor the winding used normally in the stator fig. Fall 2005 ee595s electric drive systems 3 voltsperhertz control. We have also provided number of questions asked since 2007 and average weightage for each subject. Another thing was there where people used to take two induction motors which are mechanically coupled up to different number of poles separate machines is a p 1 poles another a p 2 poles and this motor could be connected in cascade, that is, the rotor of the first motor is used to supply this stator of the second motor. Working principle of a single phase induction motor circuit. When describing a three phase induction motor by a system of non linear equations, following assumptions are made.
List the causes that are responsible for non starting of a three phase induction motor. Non excited types include reluctance motors, hysteresis motors, and permanentmagnet motors. The motor uses a squirrel cage rotor, which has a laminated iron core with slots. Working principle of a single phase induction motor a single phase induction motor consists of a single phase winding which is mounted on the stator of the motor and a cage winding placed on the rotor. Two rotating field theory, toquespeed characteristics. And if it is answers generator it will be just above 1,500 rmp we will not discuss about induction generator only little about motor right. Concept of rotating magnetic field, operating principle, construction, classification and types single phase, three phase, squirrelcage, slipring, doublecage types. Induction motors despite the fact that the three phase motor has more phases than the single phase motor, the single phase motor is a much more complex machine. Draw and explain the speedtorque characteristics of three phase. Speed control of induction motor using pwm technique. Starting of 3 phase induction motors, high starting torque motors, speed control, rheostatic method, pole changing method cascade control of speed, double cage induction motor, cogging and crawling of induction motor, induction generator. Start induction motor dynamic and steadystate performance of a. Scalar control is the term used to describe a simpler form of motor control, using non vectorcontrolled.
Different speed control methods of induction motor are explained below. The rotor will constantly be turning to align its magnetic field with that of the stator field. Other motors that are included are 1 phase induction motors, permanent synchronous motors and synchronous reluctance motors. Find the percentage slip and number of poles of the induction motor. Single phase induction motor 1introduction the single phase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Basic electrical technology nptel online videos, courses. A generalized dynamic model of induction motor using simulink. L umanand department of power electronics group, cedt iisc bangalore. Fall 2005 ee595s electric drive systems 2 overview of strategies voltsperhertz control constant slip control fieldoriented control.
Lecture series on basic electrical technology by prof. Thus, as an electrical and electronics engineer or hobbyist we must know a few basic concepts about these types of machines we use regularly in our life. Single phase motors have only two power source supply lines connected. A pulsating magnetic field is produced, when the stator winding of the single phase induction motor shown below is energised by a single phase. The proposed system is intended to offer soft start of the single phase induction motor using a pwm sinusoidal voltage while starting the motor. Craig 4 in rotational electromechanical devices other than dc machines, torque is produced as a result of one or more magnetic fields which rotate about the air gap of the device. Reluctance machines, induction machines, synchronous machines, stepper motors, and brushless dc motors. The electrical machines 3 notes pdf em iii notes pdf book starts with the topics covering constructional features of round rotor and salient pole machines, suppression of harmonics, regulation by synchronous impedance method, parallel operation of synchronous generator synchronizing alternators with infinite bus bars, theory of operation. So, now principle of induction motor right so, the operation of three phase.
Single phase means that only one voltage waveform is applied to the motor. Different situations could then be considered if this voltage source er had a non zero magnitude. An900, controlling 3phase ac induction motors using the. The theory used in the work was collected by studying literature on how electrical motors work, and by simplifying the. 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. All we need to do is to keep daxis stator current constant. Record all nameplate information for the induction motor. Basic electrical technology lecturer nptel videos description notes by prof. Before discussing the methods to control the speed of three phase induction motor one should know the necessary formulas of speed and torque of three phase induction motor as the methods of speed control depends upon these formulas 7 synchronous speed, ns. Several additional components are necessary to operate the single phase motor. Brushless dc motors nyu tandon school of engineering.
Single phase induction motor the single phase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Practicing all polyphase induction motors electrical engineering questions and answers in online helps you to improve your ability to attend the real time gate, ies and bsnl jto exams. Nptel provides elearning through online web and video courses various streams. Nov 04, 2012 introductionan induction motor im is a type ofasynchronous acmotor where power is supplied to therotating device bymeans ofelectromagneticinduction three phase induction motors 4. Nptel, online courses and certification, learn for free. Centre for engineering studies recommended for you. Electronic starters for single phase induction motor with. 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. Umanand, principal research scientist, power electronics group, cedt, iisc bangalore for more details on nptel visit. The torque produced depends on a non zero relative speed between the eld and the. Differentiate between the various types of generating electric power stations.
Induction machines guru nanak dev engineering college. List two problems each associated with over voltage and under voltage in a three phase induction motor. Assignment i visvesvaraya technological university. This strange behavior of single phase induction motor can be explained on the basis of doublefield revolving theory. A fair knowledge of distributed windings is essential in order to understand the working of rotating machines more e. Lecture notes electrical machine ii bee 1401 page 1. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. Ac motors singlephase 3phase minneapolis, mn rapid. The circuit is capable of supplying single phase induction motor inductive or resistive load with varying ac voltage. In this module we will be discussing the three phase induction machine. Perform an analysis on induction machines which is the most rugged and the most. The 3 phase 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 single phase ac motors. Note down the machine ratings and calculate rated current of the machine noload test.
The single phase motor stator has a laminated iron core with two windings arranged perpendicularly. A brief on single phase induction motor pdf elprocus. However the outputs are usually rich in harmonics and are almost always nonsinusoidal. One single phase wattmeter plus miscellaneous apparatus as needed. The basic idea of an electric motor is to generate two magnetic fields. Learn for free, pay a small fee for exam and get a certificate.
As i previously mentioned in my article on introduction to induction motors, there are two main types of induction motors, single phase induction motor and 3 phase induction motor. They run at a constant speed from noload to the full load. At the end of the lecture, student should be able to. Induction motor 1 chapter 3 induction motor bee23 electrical machine power system 2 learning outcomes. Induction motor totallyenclosed fancooled nema standard epact three phase induction motors sdesign versatility teco totally enclosed fan cooled squirrelcage induction motors are designed, manufactured and tested to meet or exceed the latest nema, ieee, csa and. This document is highly rated by electrical engineering ee students and has been viewed 2495 times. This application note also covers the basics of induction motors and different types of induction motors. Types, construction and principle of operation, 3 phase induction motor, general phasor diagram, equivalent circuit, power and torque. It supplies an induction motor ich has a full load speed of 144wh 0 rpm. A basic tutorial on computer simulation of phase controlled rectifiers using psim. Mostafa elshahed objectives learn a brief history of the electrical power systems construction. Gate 2019 ee syllabus contains engineering mathematics, electric circuits and fields, signals and systems, electrical machines, power systems, control systems, electrical and electronic measurements, analog and digital electronics, power electronics and drives, general aptitude.
A generalized dynamic model of induction motor using simulink p. Learn what a hysteresis motor is, its working principle, diagram, and its. A three phase induction motor running at a speed of 1450 rpm, is supplied from 60 hz supply. Speed control of a three phase induction motor using pwm. Explain how a rotating magnetic field is produced when the stator of a three phase induction motor is supplied from a symmetrical three phase supply. Starting of 3 phase induction motors, high starting torque motors. Induction machines 1 introduction the induction machine was invented by nikola tesla in 1888. The six switches form 3 pairs of halfbridges, which can be used to con. There are two basic reasons for the use of single phase motors rather than 3 phase motors. Dc motor, the ac induction motor, and the ac synchronous motor. Umanand, principal research scientist, power electronics group, cedt, iisc bangalore. Aluminum bars are molded on the slots and shortcircuited at both ends with a ring.
This thesis presents the need of speed control in induction motors. One is almost identical to that of the three phase induction motor while the other is of a form similar to that of the d. Speed control of a three phase induction motor using pwm inverter. When stator is energized with single phase ac supply, rotating. Doubt discussion on network and emft gateese 2021 ashu jangra duration. Today, i am gonna give you an introduction of a single phase induction motor. Ppt threephase induction motor electrical engineering. It is a single phase motor and its rotor is made of ferromagnetic material with non. Understand the principle and the nature of single phase and 3 phase induction machines. The important characteristics normally shown by a squirrel cage induction motors are crawling and cogging. Circuit diagram for noload and blockedrotor test on 3 phase induction motor a. These characteristics are the result of improper functioning of the motor that means either motor is running at very slow speed or it is not. The sinusoidal stator phase currents fed in the stator coils create a magnetic field. The rotor is of squirrel cage type, which is a cheap one, as the rating of this type of motor is low, unlike that for a three phase im.
And generally we will find it is a 4 pole machine, but the magnetic field. For the latter two technologies, we consider the case of three phase power, which is generally preferred over single phase because of much higher power density. Explain the terms synchronous watts and slip of induction motor. These characteristics are the result of improper functioning of the motor that means either motor is running at very slow speed or it is not taking the load. Disconnect any mechanical load connected to the induction motor. In operation, the rotor is magnetized with the required magnetic poles in a manner analogous to that of an induction motor. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. Sep 11, 2017 an induction motor can therefore be made without electrical connections to the rotor. Analysis of 3 phase induction motor electrical machines. Analysis and modelling of an induction machine with a. The principle of operation of a three phase induction motor using written pole technology depends on one set of. Crawling and cogging of induction motor electrical4u.
591 426 387 1633 1217 1420 51 56 84 142 674 1610 411 8 1406 1237 58 1005 349 1600 1005 82 362 1385 225 645 1268 345 675 947 1042 1191 1561 1579 98 287 182 856 268 534 1173 534