Ieee standard test procedure for polyphase induction motors and generators 3 park avenue, new york, ny 100165997, usa ieee power engineering society sponsored by the electric machinery committee 4 november 2004 print. Tesla polyphase induction motors workforce libretexts. Perhaps the most important benefit of polyphase ac power over singlephase is the design and operation of ac motors. Polyphase induction motor definition is an alternatingcurrent motor having polyphase as 3phase windings. Lecture 6 three phase induction motors cairo university. Pdf polyphase induction machines nasrin shaheen academia. Polyphase induction motors objective type questions and.
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. The electric energy generated purchased by consumers for different needs. Polyphase induction motors mcqs for preparation of fpsc, nts, kppsc, ppsc, and other test. If the rotor were to somehow turn at ss, the emf could not be induced in the rotor and therefore the rotor would stop. Com website is not the original publisher of all book on net. We additionally offer variant types and in addition to type of the books to browse. Polyphase induction motors mcqs answers pdf electrical engg. In fact, 90% of industrial motors are induction motors. Applications of induction motor polyphase wound rotor. 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.
It is simple and relatively inexpensive, and the absence of sliding contacts in the squirrelcage machine reduces maintenance to a minimum. Tesla polyphase induction motors ac motors electronics textbook. Threephase currents flowing within the stator create a rotating magnetic field which induces a current and consequent magnetic field in the rotor. That is why such motors are known as induction motors. An induction motor is composed of a rotor, known as an armature, and a stator containing windings connected to a polyphase energy source as shown in the figure below. Institute of electrical and electronics engineers subject. This standard covers instructions for conducting and reporting the more generally applicable and acceptable tests of polyphase induction motors and generators. Bookmark file pdf polyphase ac induction motor troubleshooting guide polyphase ac induction motor troubleshooting guide right here, we have countless books polyphase ac induction motor troubleshooting guide and collections to check out. Our polyphase squirrel cage induction motors are designed for across the line or increment starting as required. Objective polyphase induction motors questions and answers pdf. Nikola tesla conceived the basic principals of the polyphase induction motor in 1883, and had. Test procedure for polyphase induction motors and generators author.
However, if the rotor stopped or even if it slowed significantly, an emf. Ac motors polyphase peerless electric designs 3phase motors from 120 to 50 hp in various frame sizes from 4. 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. On the other hand, the polyphase induction motor shown in cutaway in fig. The advantages of threephase ac induction motor are listed below. Polyphase motors was founded in 1975, by a technocrat, with the experience in design and production departments of a leading mnc motor manufacturer. The effect of unbalanced voltages on polyphase induction motors is equivalent to the. The requirements in this standard apply to 60hertz polyphase induction motors intended for use in power generating stations, including the following 1 frame size larger than nema 440 2 squirrelcage type 3 single speed or multispeed 4 horizontal or vertical construction. Therefore, motor troubleshooting involves the entire system, not just the. In polyphase induction machine both the stator and rotor winding carry alternating currents.
Polyphase induction motors for power generating stations part i. Polyphase ac motors polyphase motors make up the largest single type in use today and usually are the first to be considered for the average industrial application. Objective polyphase induction motors questions and answers pdf 71. Pdf drfoc of polyphase induction motor based on fuzzy logic. The rotor in an induction motor can not turn at the synchronous speed. Ieee standard test procedure for polyphase induction motors and generators. Selfstarting polyphase induction motors produce torque even at standstill.
Mostafa elshahed objectives learn a brief history of the electrical power systems construction. Different methods of speed control of threephase asynchronous. 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. The most common type of motor in this group is the squirrelcage polyphase induction motor so. Available squirrel cage induction motor starting methods include directonline starting, reducedvoltage reactor or autotransformer starting, stardelta starting or, increasingly, new solidstate soft assemblies and, of course, variable frequency drives vfds. Polyphase motor design polyphase ac circuits electronics. Ieee standard test procedure for polyphase induction motors. Ieee standard test procedure for polyphase induction. Equivalent circuit for a polyphase induction motor request pdf. An induction motor can therefore be made without electrical connections to the rotor. Tesla polyphase induction motors summary a polyphase induction motor consists of a polyphase winding embedded in a laminated stator and a conductive squirrelcage embedded in a laminated rotor. Tesla polyphase induction motors ac motors electronics.
Presently, the unit has developed more than one thousand five hundred electrical and mechanical designs of motors. Ieee std 1122004, ieee standard test procedure for. Polyphase induction motor definition of polyphase induction. Polyphase induction motor mcq set 03 mcq polyphase ind motors edit practice test. 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. Pdf in polyphase induction machine both the stator and rotor winding carry alternating currents. We design our ac polyphase induction motors and motor parts for variable speed applications in conjunction with many scr drives on the market today. 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. Overview this user manual applies to nord motor products and it provides general information for motor operation, installation, maintenance, inspection, repair, and trouble shooting, which is relevant to most of the motor products shipped by nord. Problems and premature failures often indicate input power system troubles, poor or deteriorating mechanical installations, or malfunctions in the driven machinery.
Pdf noise of polyphase electric motors joseph lai and. Applications of polyphase induction motors instrumentation tools. Pdf this paper presents a new control system of the sevenphase induction machine based on direct rotor field oriented control technique. Hiried polyphase induction motors multiple choice questions. Polyphase induction motors mcqs for preparation pakmcqs. 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. The simple 2phase induction motor below is similar to the 12 horsepower motor which nikola tesla introduced in 1888. For which motor the speed can be controlled from rotor side. The standard 3phase powered motor applied to the widest range of drives.
Direct rotor field oriented control of polyphase induction. You should also make a dc measurement of stator winding linetoline resistance using a dmm. These motors are widely used in industrial drives, particularly polyphase induction motors, because they are rugged and. In fact, an induction motor can be treated as a rotating transformer i. An induction motors rotor can be either wound type or squirrelcage type. View notes polyphase induction motor from engineerin ece523 at university of the immaculate conception, davao city. The stator produced flux rotates in synchronous speed with respect to stator. Hiried polyphase induction motors multiple choice questions and answers pdf 41. Polyphase power is particularly useful in ac motors, such as the induction motor, where it generates a rotating magnetic field. Polyphase induction motors, analysis by paul cochran. Ieee std 1122004, ieee standard test procedure for polyphase. Direct rotor field oriented control of polyphase induction machine based on fuzzy logic controller april 2017 revue roumaine des sciences techniques serie electrotechnique et energetique 621. In order to induce an emf in the rotor, the rotor must move slower than the ss. Polyphase induction motor mcq set 03 objectivebooks.
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. Instructions for conducting and reporting the more generally applicable and acceptable tests of polyphase induction motors and generators are covered. Home free online polyphase induction motors electrical engineering quiz questions test polyphase induction motors objective type questions and answers pdf. Applications of induction motor the polyphase induction motor is a motor whose stator contains a number of windings. The power factor of an induction motor under noload conditions will be closer to. When a threeormorephase supply completes one full cycle, the magnetic field of a twopolesperphase motor has rotated through 360 in physical space. Polyphase induction motors for power generating stations. Polyphase induction motor chapte r 5 polyphase induction. Our polyphase motors vary in size from 120 to 50 horsepower, 690, 850, 1150, 1750, 3500 rpm. In the circle diagram for induction motor, the diameter of the circle represents a slip b rotor current c running torque d line voltage ans. The national electrical manufacturers association nema has specified the motors according to the various class, which are discussed below in detail. The manufacturers produce motors to suit the load requirements, mains voltages, operating times and starting requirements. The purpose of using shortcircuit gear is a to short circuit the rotor at slip rings b to short circuit the starting resistances in the starter c to short circuit the stator phase of motor to form star.
May 20, 2020 polyphase induction motor mcq with explanation in case of 3 phase induction motors the ratio of core length to pole pitch for minimum cost is taken as. We classify starting methods for squirrel cage induction motor into two types on the basis of voltage. Starting methods for polyphase induction machine electrical4u. There are two general types of polyphase induction motors. A 3 phase induction motor can be used for different applications with various speed and load requirements. Tesla, as a difference from his contemporaries, was the first to prove experimentally that induction motors with high degree of efficiency can be made. This ebooks download link has been collected from other sites on internet. In this circuit, lis and llr represent respectively the. The rotor of a polyphase induction machine may be one of two types. List and describe the more commonly used equipment in an electric substation. One singlephase wattmeter plus miscellaneous apparatus as needed. All the rights on this book belongs to publisher of these books. 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. Differentiate between the various types of generating electric power stations.
You should also make a dc measurement of stator winding linetoline resistance. Model repair specifications for low voltage induction motors. Polyphase induction motors mcqs answers pdf electrical. These epochal inventions obviously include the teslas system of poly phase alternate currents and teslas induction motor. They are greater than one horse power or one kilowatt. Induction motors are favored due to their ruggedness and simplicity.
Record all nameplate information for the induction motor. Operation and application of polyphase induction motors. Teslas polyphase system and induction motor serbian journal of. The polyphase squirrel cage induction motor can handle heavyduty requirements. Standard 3phase motors have power ratings from about 60 w upwards. 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.