Diagnostics of rotor and stator problems in industrial induction motors by fang duan b. In fact, a given synchronous machine may be used, at least theoretically, as an alternator, when driven mechanically or as a motor, when driven electrically, just as in the case of d. Pdf electric machines by dp kothari and ij nagrath pdf. His new type of motor, the ac induction motor, is the workhorse of the industry to this day. Jan 30, 2019 applied intelligent control of induction motor drives about the book. 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 an d crawling of induction motor, induction generator.
Ueeneeg006a solve problems in single and three phase low voltage machines date this document was generated. The basic idea of an electric motor is to generate two magnetic fields. Power electronics and motor drive systems sciencedirect. The three phase induction motors are simple in construction, rugged. Download 3000 solved problems in electric circuits. Synchronous and induction motors synchronous motor applications learning objectives 1490 electrical technology 38. How to solve common electric motor problems and get great. To achieve long motor life in wet environments, like a dairy processing plant, standard motor construction and standard water ingress protection are insufficient. Introduction to ac motors ac motors electronics textbook.
A threephase induction motor problem this application note describes how to set up, solve, and analyze the results of a twopole, threephase induction motor using rmxprt. A threephase stator similar to that of an induction motor. Download applied intelligent control of induction motor. Discover more publications, questions and projects in induction motor. The motor cad electromagnetic module uses both analytical algorithms and 2d finite element analysis to calculate the electromagnetic performance. Diagnostics of rotor and stator problems in industrial. Here are a collection of statements which can be proved by induction. Induction problems induction problems can be hard to. A threephase induction motor problem enginuity systems. Mathematical induction tom davis 1 knocking down dominoes the natural numbers, n, is the set of all nonnegative integers. After overheating, a motor may run satisfactorily but its useful life will be shorter.
An induction motor also known as an asynchronous motor is a commonly used ac electric motor. The 3phase set of currents, each of equal magnitude and with a phase. Download free book applied intelligent control of induction motor drives first edition by keli shi pdf. Author stefanos manias supplies a detailed discussion of the theory of power electronics circuits and electronic power conversion technology. This is very commonly used starter, compared to the other types of the starters. Jul 29, 2019 free book power electronics and motor drives seconde edition by bogdan m wilamowski and j david irwin pdf. 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. Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. A wound rotor rotating field which has the same number of poles as the. The changes are made keeping the original flavor of the book intact, that is, indepth coverage of fundamental concepts. The speed of rotation of an induction motor is fairly constant, but it does vary somewhat with loading.
Use the principle of mathematical induction to show that xn solved problems. Based on type of phase supply three phase induction motor self starting in nature. 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. Ueeneeg006a solve problems in single and three phase low. Its ruggedness and simplicity make for long life, high reliability, and low maintenance. There are various methods of speed control for an induction motor. The induction motor stator resembles the stator of a revolving field, three phase alternator. The aim of this book is to explore new areas of aibased motion control in order to make the control unit less sensitive to parameterized changes. Electric motor failures can be due to mechanical component failure or electrical circuit failure. Introduction to ac motors chapter ac motors pdf version. A 460 v, 25hp, 60hz, fourpole, yconnected woundrotor induction motor has the following impedances in ohms per phase referred to the stator circuit. Record all nameplate information for the induction motor.
The induction motor is discussed in detail in this unit. Its main function is to support the stator core and the field winding. Induction problem set solutions these problems flow on from the larger theoretical work titled mathematical induction a miscellany of theory, history and technique theory and applications for advanced secondary students and first year undergraduates. Extending binary properties to nary properties 12 8. The primary damage caused by excess heat is to increase the aging rate of the insulation. The stator or the stationary part consists of three phase winding held in place in the slots of a laminated steel core which is enclosed and supported by a cast iron or a steel frame as shown in fig. Wind pushes the blades of the turbine, spinning a shaft attached to magnets. The induction motor is made up of the stator, or stationary windings, and the rotor. Induction motors the single phase equivalent circuit of a threepha.
The rotor of an induction motor can be a squirrel cage rotor or wound type rotor. At starting, the stator winding is connected in star, therefore the applied voltage to each phase of winding is 1v3 of. Quite often we wish to prove some mathematical statement about every member of n. Further work is suggested to refine the equivalent impedance presented in this thesis. A 480v, 60 hz, 6pole, threephase, deltaconnected induction motor has the. Synchronous and asynchronous ac inductionasynchronous motor an induction or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque is induced by electromagnetic induction from the magnetic field of the stator winding. Synchronous motor the synchronous motor runs at a constant speed re. Telecommunication engineering, southwest jiaotong university, china, 2005 thesis submitted for the degree of masters of engineering science in school of electrical and electronic engineering the university of adelaide, australia august 2010. Most of single phase induction motors use squirrel cage rotor as it has a. However, recently, it has been increasingly used as variable speed motors driven by an inverter. Due to this an induction motor is sometimes referred to as an asynchronous machine. Find the percentage slip and number of poles of the induction motor. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation.
The rotor speed of a 4 pole induction motor at 50 hz is 1200 rmin. Performance of a capacitorstart singlephase induction motor. Most texts only have a small number, not enough to give a student good practice at the method. It supplies an induction motor ich has a full load speed of 144wh 0 rpm. Nov 03, 2019 an induction motor also known as an asynchronous motor is a commonly used ac electric motor. Though few ac motors today bear any resemblance to dc motors, these problems had to be solved before ac motors of any type could be properly designed. In fact, a given synchronous machine may be used, at least theoretically, as an alternator, when driven. The model created by rmxprt will then be used as an input for empulse as a basis for performing more detailed analysis and for increasing the accuracy of the performance pre.
A comparison of induction motor starting methods being. Apr 10, 2015 this is very commonly used starter, compared to the other types of the starters. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. Electric machines by dp kothari and ij nagrath now in its 5. As its name indicates stator is a stationary part of induction motor. Nov 16, 2015 explains construction of circle diagram of three phase induction motor. Excessive heat is both a cause of motor failure and a sign of other motor problems. A stator winding is placed in the stator of induction motor and the three phase supply is given to it.
Power electronics and motor drive systems is designed to aid electrical engineers, researchers, and students to analyze and address common problems in stateoftheart power electronics technologies. Synchronous motors synchronous motors are threephase ac motors which run at synchronous speed, synchronous motors have the following characteristics. Induction motor solved problems examples, torque, starting torque, power developed how to find slip of induction motor how to find synchronous speed of induction motor. Stator frame it is the outer most part of the three phase induction motor. The rotor of an induction motor can be a squirrel cage rotor or wound. Induction motors have been traditionally used as constant speed motors supplied by the ac power source. Stardelta starter can be used, provided the stator of the 3o induction motor is designed for delta connection during its normal operation. It is unitless and is the ratio between the relative speed of the magnetic field as seen by the rotor to the speed of the rotating field. The minimum solution based on symmetry is automatically selected for the finite element calculations. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. You should also make a dc measurement of stator winding linetoline resistance using a dmm.
This article presents a basic explanation of electric motor construction and. Construction and principle of operation of singlephase transformer, emf equation, singlephase autotransformer. Numerical methods for identification of induction motor. Yet small brushed ac motors, similar to the dc variety, persist in small appliances along with small tesla induction motors. Solving the model can now be solved by clicking on the solve button. These equations can be solved for r2, x1, and x2 as follows. The rotor will constantly be turning to align its magnetic field with that of the stator field. Heat beyond the insulations rating shortens winding life. In general, the induction motor is cheaper and easier to maintain compared to other alternatives. Pdf electric machines by dp kothari and ij nagrath pdf download. Induction motor problems and solutions pdf three phase induction motor 3 phase induction motor pdf the wound rotor induction motor speed control of induction motor three phase induction motor diagram speed control of induction motor by vf method blocked circle diagram of an induction motor single phase induction motor pdf free download speed.
1156 221 214 700 109 368 888 20 744 1054 1086 1331 255 55 93 1029 1282 566 781 918 1337 568 1226 696 396 970 222 819 1485 197 1539 843 1299 1076 922 233 283 852 794 1111 648