It has been shown in chapter 1 that the polyphase induction motor can be considered as a polyphase transformer with variable frequency in the shortcircuited secondary winding and an equivalent circuit can be derived per phase of the motor in the same general way as that of a transformer. Starting methods for polyphase induction machine february 17, 2019 february 24, 2012 by electrical4u in this article we are going to discuss various methods of starting a 3 phase induction motor. Isbn 07389785 ss95211 no part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. By order of the executive director office of the federal register washington, d. In a threephase induction motor, the number of poles in the rotor winding is always a zero b more than the number of poles in stator c less than number of poles in stator d equal to number of poles in stator ans. Our polyphase squirrel cage induction motors are designed for across the line or increment starting as required. Ieee standard test procedure for polyphase induction motors. In general, the induction motor is cheaper and easier to maintain compared to other alternatives. Home mcq polyphase ind motors polyphase induction motor mcq set 03 polyphase induction motor mcq set 03. The frame of an induction motor is usually made of a silicon steel b cast iron. Feb 12, 2017 it is a motor, that works only with 3 phases or harmonics of 3, where application of voltage induces a rotating magnetic field or rather, the varying values of voltage values make it seem like the field is rotating, which causes a shorted roto. Dol starting of induction motors is usually restricted to a low horsepower motors b variable speed motors.
In this study an equivalent circuit is proposed that permits the analysis of, or even the calculation for, singlephase, twophase and threephase induction motors. An induction motor or asynchronous motor is an ac electric motor in which the electric current. It is a motor, that works only with 3 phases or harmonics of 3, where application of voltage induces a rotating magnetic field or rather, the varying values of voltage values make it seem like the field is rotating, which causes a shorted roto. Polyphase induction motors mcqs answers pdf electrical engg. Polyphase induction motors, electrical engineering multiple choice questions objective type questions, mcqs, with question and answers, download free pdf, electrical engineering, multiple choice questions, objective type questions, electrical engineering short notes, rapid fire notes, best theory. Thermodynamics questions and answers pdf free download 1.
As we studied in the first chapter of this book, some types of ac motors are virtually identical in construction to their alternator generator counterparts, consisting of stationary wire windings and a rotating magnet assembly. Dawns little brother jeff is visiting the new schaferspier family. Equivalent circuit for a polyphase induction motor request pdf. Us6054837a polyphase induction electrical rotating machine. The machine is constructed with concentrated full span windings. This standard covers instructions for conducting and reporting the more generally applicable and acceptable tests of polyphase induction motors and generators.
It is simple and relatively inexpensive, and the absence of sliding contacts in the squirrelcage machine reduces maintenance to a minimum. Instructions for conducting and reporting the more generally applicable and acceptable tests of polyphase induction motors and generators are covered. Determination of the losses in induction machines due to harmonics pdf. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. Nikola tesla conceived the basic principles of the polyphase induction motor in 1883 and had a half horsepower 400 watts model by 1888. Polyphase induction motors electrical engineering questions. Perhaps the most important benefit of polyphase ac power over singlephase is the design and operation of ac motors. The rotor of a polyphase induction machine may be one of two types. Teslas polyphase system and induction motor 125 understand why the motor does not have the highest torque at start, and because of the second mistake he came to the wrong conclusion that that motor can not have the efficiency higher than 0. Squirrelcage induction motor the operation of the squirrelcage motor is simple. In the drawing, a represents the primary winding of the motor.
In fact, 90% of industrial motors are induction motors. Therefore it will be essential for you to distinguish. Polyphase induction motors quiz questions and answers. The rotor will constantly be turning to align its magnetic field with that of the stator field. Starting of 3 phase induction motors, high starting torque motors. Most asked objective questions or mcq on polyphase induction motors electrical engineering. S bimbhra pdf download free if you are finding the electrical machine by ps bimbhra pdf then this is the right plac. Home interview questions on polyphase induction motors electrical engineering realtime polyphase induction motors multiple choice questions and answers pdf realtime polyphase induction motors multiple choice questions and answers pdf. The rheostatic braking with a polyphase induction motor can be obtained by disconnecting the stator winding from the ac supply and exciting it from a dc source to produce a stationary dc field. Ac motors polyphase peerless electric designs 3phase motors from 120 to 50 hp in various frame sizes from 4. Drfoc of polyphase induction motor based on fuzzy logic controller speed.
We use cookies to make interactions with our website easy and meaningful, to better understand the use of our services, and to tailor advertising. Many of the tests described may be applied to both motors and generators, as needed, and no attempt is made to partition the test procedure into clauses and subclauses that separately apply to motors or to generators. Sep 02, 2014 101 top polyphase induction motors electrical engineering multiple choice questions and answers. There are two general types of polyphase induction motors. The first ac commutatorfree threephase induction motors were independently invented by. Polyphase power is particularly useful in ac motors, such as the induction motor, where it generates a rotating magnetic field. The guide includes practical information about the proper selection, installation. In an induction motor,esecondarg structure comprising a. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. Polyphase induction motors for power generating stations. Which of the following component is usually fabricated out of silicon steel. Working of 3 phase induction motor is explained in this video with help of animation. Click download or read online button to get asynchronous machines book now. He is miserable because all his old friends have changed, and.
S bimbhra pdf download free if you are finding the electrical machine by ps bimbhra pdf then this is the right place for you. Us5214366a threephase converter for polyphase induction. Various methods of speed control 3phase induction motor. Test procedure for polyphase induction motors and generators. This book places emphasis on practice through the use of extensive modeling, simulation and analysis to. Ac induction motors are also the most common motors used in main powered home appliances. A 3phase induction motor stator delta connected, is carrying full load and one of its fuses blows out.
Polyphase induction motors mcqs answers pdf electrical. Polyphase induction motors, analysis by paul cochran. Remember that you are working with polyphase power. Ieee std 1122004 revision of ieee std 1121996 ieee standard test procedure for polyphase induction motors and generators sponsor electric. Polyphase induction motor definition is an alternatingcurrent motor having polyphase as 3phase windings.
Home category electrical engineering mcq questions and answers 3 phase induction motors 1 the frequency of the induced emf in an induction motor is a. We classify starting methods for squirrel cage induction motor into two types on the basis of voltage. Principle of operation of single phase induction motor. Record all nameplate information for the induction motor. Other readers will always be interested in your opinion of the books youve read. Polyphase induction motors for power generating stations part i. The threephase induction motor is the extensively used for various kinds of industrial drives. A 3 phase induction motor can be used for different applications with various speed and load requirements. Starting methods for polyphase induction machine electrical4u.
On the other hand, the polyphase induction motor shown in cutaway in fig. Home electrical engineering multiple choice questions 110 top most polyphase induction motors electrical engineering multiple choice questions and answers. Download as ppt, pdf, txt or read online from scribd. Nema mg 102017 energy management guide for selection and use of fixed frequency medium ac squirrelcage polyphase induction motors. Asynchronous machines download ebook pdf, epub, tuebl, mobi. Jul 02, 20 working of 3 phase induction motor is explained in this video with help of animation. Polyphase induction motors mcqs answers electrical engineering multiple choice questions answers pdf download. Common highway engineering civil engineering objective type questions and answers pdf. 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. Test procedure for polyphase induction motors and generators name of standards organization.
Objective polyphase induction motors questions and answers pdf 71. Design, and application electrical and computer engineering cochran, paul on. Ieee std 1122004 ieee standard test procedure for polyphase induction motors and generators. Here basic operation principle of an induction motor is.
Induction motors are favored due to their ruggedness and simplicity. The book covers topics such as the modeling of steadystate motor performance polyphase induction, synchronous, and a. Request pdf equivalent circuit for a polyphase induction motor in this study an equivalent circuit is proposed that permits the analysis of, or even the calculation for, singlephase, two. Which of the following variables controls the physical properties of a perfect. A threephase converter for polyphase induction motors has an input transformer with primary windings and at least two secondary windings associated with each primary winding, and controlled power semiconductors. Polyphase induction motors mcq question is the important chapter for a electrical engineering and gate students. A polyphase induction machine operated by an inverter drive system.
Home most asked objective questions or mcq on polyphase induction motors electrical engineering latest polyphase induction motors multiple choice questions and answers pdf. The polyphase current produces a rotating magnetic. If an induction motor with certain ratio of rotor to stator. The squirrelcage motor is the simplest to manufacture and the easiest to maintain. The electric energy generated purchased by consumers for different needs. The most common type of motor in this group is the squirrelcage polyphase induction motor so called because the rotor is constructed like a squirrelcage fig. Pdf polyphase induction machines nasrin shaheen academia. Twelve or more phases are used to sufficiently cover the airgap region, in contrast to the conventional three phases using distributed and chorded windings. Latest polyphase induction motors multiple choice questions and answers pdf. The 3phase set of currents, each of equal magnitude and with a phase. Ieee std 1122004, ieee standard test procedure for. Equivalent circuit for a polyphase induction motor.
An induction motors rotor can be either wound type or squirrelcage type. An induction motor can therefore be made without electrical connections to the rotor. Polyphase induction motor definition of polyphase induction. Whether youve loved the book or not, if you give your honest and detailed thoughts then people will find new books that are right for them.
Motor wg112 motor sc test procedure for polyphase induction motors and generators. Polyphase induction motor mcq set 03 objectivebooks. The polyphase induction motor is the most commonly used industrial motor. Ieee std 1122004, ieee standard test procedure for polyphase. Us6054837a polyphase induction electrical rotating. The advantages of threephase ac induction motor are listed below. Threephase cage induction motors are the most widely used for ancillary. Download free ebooks home engineering mechanical engg. Krishnan electronic control of machines develops a systematic approach to motor drives. Therefore, motor troubleshooting involves the entire system, not just the.
Cage induction motor an overview sciencedirect topics. Ieee standard test procedure for polyphase induction. The polyphase induction motor the polyphase induction motor is the most commonly used industrial motor, finding application in many situations where speed regulation is not essential. Objective polyphase induction motors questions and answers pdf. Design, and application electrical and computer engineering. Nema publishes energy management guide for polyphase. The basic idea of an electric motor is to generate two magnetic fields. The national electrical manufacturers association nema released a new energy management guide for polyphase induction motors. Electrical braking in polyphase induction motors electrical. 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. In rheostatic braking, the stator winding is employed as a dc field winding and the rotor winding as an armature winding. You should also make a dc measurement of stator winding linetoline resistance using a dmm. The induction motor is made up of the stator, or stationary windings, and the rotor. Institute of electrical and electronics engineers legally binding document.
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