An induction motor or asynchronous motor is an ac electric motor in which the electric current. One of the original ac tesla induction motors on display in the british science museum in london. However, predicting noise of an electrical motor is more difficult and less accurate than for other characteristics such as torquespeed. Download it once and read it on your kindle device, pc, phones or tablets. Prior to the advent of the adjustablespeed drive asd, the polyphase induction motor operated as a constantspeed motor. The total instantaneous power of a polyphase source is constant if the load on each phase of it is identical. A by changing the number of stator poles b rotor rheostat control. The nature of polyphase induction machines philip l. 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. Instructions for conducting and reporting the more generally applicable and acceptable tests of polyphase induction motors and generators are covered. It is simple and relatively inexpensive, and the absence of sliding contacts in the squirrelcage machine reduces maintenance to a minimum. Home mcq polyphase ind motors polyphase induction motor mcq set 03 polyphase induction motor mcq set 03 mcq polyphase ind motors edit practice test. Polyphase reaction synchronous motors ieee journals. 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.
Ipts industrial trade books are used extensively throughout canada, north america and overseas. Recent advances have produced powerful computational methods for noise prediction, and noise of polyphase electric motors is the first book to collect these advances in a single source. Tesla polyphase induction motors workforce libretexts. Polyphase induction motors objective questions set 01. The polyphase induction motors, however, have certain inherent advantages. Design, and application electrical and computer engineering 1st edition by paul cochran author. Model repair specifications for low voltage induction motors these model repair specifications are intended to cover routine repair and rewind of lowvoltage randomwound threephase ac squirrel cage induction motors. Tesla polyphase induction motors ac motors electronics. Which of the following methods is easily applicable to control the speed of the squirrelcage induction motor. Generously illustrated with over 1600 dispaly equations and more than 145 drawings, diagrams and photographs, this book is a handy. Grundfos motor book 12 grundfos motor book when an ac supply is applied the phase windings and number of poles 3phase, 2pole motor. The manufacturers produce motors to suit the load requirements, mains voltages, operating times and starting requirements. Home books induction motors applications, control and fault diagnostics. An induction motors rotor can be either wound type or squirrelcage type.
An induction motor is composed of a rotor, known as an armature, and a stator containing windings connected to a poly phase energy source as shown in figure below. The book has almost a complete course for design and analysis of three phase induction motors. The first ac commutatorfree threephase induction motors were independently invented. 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.
Nema mg 102017 energy management guide for selection and use of fixed frequency medium ac squirrelcage polyphase induction motors. Teslas ac induction motor is one of the 10 greatest. Polyphase coils are electromagnetic coils connected together in a polyphase system such as a generator or motor. Each phase carries a sinusoidal alternating current whose phase is delayed relative to one of its neighbours and advanced relative to its other neighbour. We design our ac polyphase induction motors and motor parts for variable speed applications in conjunction with many scr drives on the market today. Recent advances have produced powerful computational methods for noise prediction, and noise of polyphase electric motors is. Visualization of a threephase induction motor as a generalized transformer. Design, and application crc press book generously illustrated with over 1600 dispaly equations and more than 145 drawings, diagrams and photographs, this book is a handy, singlesource reference suited to readers with a wide span of educational backgrounds and technical experience.
The rotor of an induction motor can be a squirrel cage rotor or wound. Polyphase induction motors, analysis by paul cochran. If you have access to algers precious book and you dont. The polyphase squirrel cage induction motor can handle heavyduty requirements. Teslas ac induction motor is one of the 10 greatest discoveries of all time above. 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. An induction motor can therefore be made without electrical connections to the rotor. Motor wg112 motor sc test procedure for polyphase induction.
Polyphase induction motors mcq question is the important chapter for a electrical engineering and gate students. This standard covers instructions for conducting and reporting the more generally applicable and acceptable tests of polyphase induction motors and generators. Modeling and analysis of induction machines sciencedirect. A polyphase induction motor consists of a polyphase winding embedded in a laminated stator and a conductive squirrelcage embedded in a laminated rotor. Polyphase induction motor mcq set 03 objectivebooks. At first it was used only in connection with instruments, such as the oscillograph etc later its simplicity and. Home mcq polyphase ind motors polyphase induction motors objective questions set 01 polyphase induction motors objective questions set 01 mcq polyphase ind motors edit practice test. The purpose of using shortcircuit gear is a to short circuit the rotor at slip rings.
The guide includes practical information about the proper selection, installation, operation and maintenance of. The squirrelcage motor is the simplest to manufacture and the easiest to maintain. 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. The standard 3phase powered motor applied to the widest range of drives. Induction motors analysis and torque control bahram amin. New york mcgrawhill, 1958, by charles seymour siskind page images at hathitrust a photographic method of determining performance characteristics of a polyphase induction motor, ithaca, n. Problems and premature failures often indicate input power system troubles, poor or deteriorating mechanical installations, or malfunctions in the driven machinery. Page 8 by revolving in a uniform field the electromotive forces set up are proportional to the sine of the angle through which the coil has turned from the position in which it lay across the field. In the summer of 1885 he conceived the idea that two outofphase, but synchronized, currents might be used to produce two magnetic fields that could be combined to produce a rotating field without any need for switching or for moving parts. For motors falling outside this description, the more comprehensive model specifications below are recommended. You should also make a dc measurement of stator winding linetoline resistance using a dmm. Our polyphase motors vary in size from 120 to 50 horsepower, 690, 850, 1150, 1750, 3500 rpm. Polyphase induction motor definition is an alternatingcurrent motor having polyphase as 3phase windings.
Openphase fault operation on multiphase induction motor drives. The stator in the figure above is wound with pairs of coils corresponding to the phases of electrical energy. Model repair specifications for low voltage induction motors. 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. Perhaps the most important benefit of polyphase ac power over singlephase is the design and operation of ac motors. The simple 2phase induction motor below is similar to the 12 horsepower motor which nikola tesla introduced in.
The good power factor of an induction motor can be achieved if the average flux density in the air gap is a absent b small c large d infinity ans. 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. 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. Design, and application electrical and computer engineering book 59 kindle edition by paul cochran. Ieee std 1122004, ieee standard test procedure for. Ieee standard test procedure for polyphase induction. In modern systems, the number of phases is usually three or a multiple of three. Operation and application of polyphase induction motors.
This book provides a thorough approach for mastering the behavior and. The transient analysis of both threephase and singlephase induction motors as well. Standard 3phase motors have power ratings from about 60 w upwards. Presently, the unit has developed more than one thousand five hundred electrical and mechanical designs of motors. Record all nameplate information for the induction motor. Learn definitions, uses, and phrases with polyphase motor. Nema publishes energy management guide for polyphase. 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. In an induction motor, the electric current in the rotor needed to produce torque is obtained via electromagnetic induction from the rotating magnetic field of the stator winding. This website uses cookies to improve your experience. Figure 1 shows the wellknown torque and current curves versus speed for the motor, where the operating speed is close to 1,800 revolutions per minute. Faulttolerance in threephase drives for different types of faults is a viable and. Well assume youre ok with this, but you can optout if you wish. Therefore, motor troubleshooting involves the entire system, not just the.
Threephase currents flowing within the stator create a rotating magnetic field which induces a current and consequent magnetic field in the rotor. Polyphase motors was founded in 1975, by a technocrat, with the experience in design and production departments of a leading mnc motor manufacturer. Polyphase motor is contained in 1 match in merriamwebster dictionary. Theory is dealt with in separate sections, and may be omitted at will by some readers. Advantages of polyphase system electrical academia. This book was first published in 1951 and was written by designers of polyphase commutator machines for students, and for engineers interested in their application. If in this position the flux of magnetic lines through it were n, and the number of spirals in the coil that enclose the n lines be called s, then, as was shown on p. Teslas polyphase system and induction motor petar miljanic1 1 introduction while new scientific knowledge is acquired by learning, observation, experiments and thinking, the inventions are mostly the fruit of the intuition of individuals and of their creative impulses. An induction motor also known as an asynchronous motor is a commonly used ac electric motor.
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