Free download induction motor seminar ppt, pdf report. List and describe the more commonly used equipment in an electric substation. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. P number of poles for more details about rotating magnetic field, read production of rotating magnetic field this rotating field passes through the air gap and cuts the rotor conductors, which are stationary. Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. The first ac commutatorfree threephase induction motors were. It is also called asynchronous motor because it does not run at a synchronous speed. The national electrical manufacturers association nema has specified the motors according to the various class, which are discussed below in detail. Induction motor 1 chapter 3 induction motor bee23 electrical machine power system 2 learning outcomes. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Get motor rewinding procedure pdf file for free from our online library pdf file.
There are two types of induction motors, one is named as single phase induction motor, while the second one is named as 3 phase induction motor. Motor types three types of motors are used in agriculture. Applications of threephase induction motors of size varying from half a kilowatt to thousands of kilowatts are numerous. Some of the advantages of induction motors compared to dc motors and synchronous motors. An electrical motor is a device that has brought about one of the biggest advancements in the fields of engineering and technology ever since the invention. Mostafa elshahed objectives learn a brief history of the electrical power systems construction. Induction motors are of two types based on the construction. An induction motor can be treated as a rotating transformer i. The three phase induction motors are simple in construction, rugged, low cost. Use of synchronous motors and dc motors for heavy duty and precision drives etc. The rotor of an induction motor can be a squirrel cage rotor or wound type rotor. So called because rotor tries to line up with the rotating magnetic field in the stator. A 3 phase induction motor has two main parts i stator and ii rotor. In induction motors, the induced magnetic field of the stator winding induces a current in the rotor.
A three phase supply is given to the stator of the induction motor. In general, the induction motor is cheaper and easier to maintain compared to other alternatives. The winding wound on the stator of three phase induction motor is also called field winding and when this winding is excited by three phase ac supply it produces a rotating magnetic field. Instead the rotor is wound with shorted turns in which the environmental field induces a current. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. 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. How an induction motor works by equations and physics.
Different motors are suitable for different applications. But the rotor construction differs with respect to the type of motor. So obviously the speed of an induction motor can be controlled by varying any of three factors namely supply frequency f, number of pole p or slip s. As the name indicates stator is a stationary part of induction motor. An887, ac induction motor fundamentals microchip technology. Construction of induction motor the three phase induction motor is a preferable type of motor. The rotor is separated from the stator by a small airgap which ranges from 0. 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. Various types of ac induction motors are available in the market.
Although ac induction motors are easier to design than dc motors, the speed and the torque control in various types of ac induction motors require a greater understanding of the design and the. Therefore such motors are known as induction motors. Enter your email below to receive free informative articles on electrical. The most common type of ac motor being used throughout the work today is the induction motor. Its ruggedness and simplicity make for long life, high reliability, and low maintenance. Motor speed relationship the synchronous speed of an ac motor is the speed of the rotating magnetic field set up by the stator winding synchronous speed rpm 120 x frequency divided by the number of poles. Like any other electrical motor, induction motors have two main parts the rotor and the stator. The main methods employed for speed control of induction motors are as follows. Squirrel cage and wound rotor or slip rig induction motor. An induction motor is also called asynchronous motor as it runs at a speed other than the synchronous speed. Induction motor is an ac electric motor, having a stator and a rotor just like other motors, but the working principle is a little different which would be discussed further. The stator of three phase induction motor is made up of numbers of slots to. Induction motor the induction motor is the motor most commonly used in agriculture. The construction of stator of the induction motor is almost the same as other motors.
An induction motors rotor can be either wound type or squirrelcage type. They are greater than one horse power or one kilowatt. Abstractamongst many types of electrical motors, induction motors still enjoy the same popularity as they did a century ago. That current in turn produces a field that interacts with the environment to drive the rotor. Development of the induction motor equivalent circuit. The induction motor has two sets of windings copper or aluminum wire coiled to form electromagnets. Singlephase motors have only two power source supply lines connected.
There are mainly two types of induction motor on the basis of power supply, single phase induction motor and three phase induction motor. With the introduction of variable frequency drives for speed and torque control, the 3phase induction motors are finding increasingly acceptable for applications. It has the stator of an induction motor, and the rotor of a dc motor. The induction motor is made up of the stator, or stationary windings, and the rotor.
Several additional components are necessary to operate the singlephase motor. Differentiate between the various types of generating electric power stations. In this type of three phase induction motor the rotor is wound for the same number of poles as that of stator but it has less. The speed of rotation of an induction motor is fairly constant, but it does vary somewhat with loading. A simple explanation of how a 3 phase induction motor works. A threephase ac induction motor is the only type where the rotating magnetic field is created naturally in the stator because of the nature of the supply. Slip ring induction motor is made up from wound rotor and squirrel cage induction motor is made up from the squirrel cage rotor. His new type of motor, the ac induction motor, is the workhorse of the industry to this day. A good material for the poles of a pmdc motor should have the apposite of the above. In industry, most commonly used motors are 3 phase squirrel cage induction type. Squirrel cage induction motor and slip ring induction motors. Squirrel cage induction motor is used in lathes, drilling machine, fan, blower printing machines etc. Speed control of induction motors the speed of an induction motor is given as n 120fp 1s. Introduction to induction motor the engineering projects.
At the end of the lecture, student should be able to. This induced rotor current produces a second magnetic field, which tries to oppose the stator magnetic. Applications of induction motor polyphase wound rotor. Read online now motor rewinding procedure ebook pdf at our library. The threephase induction motor is the easiest motor of this type to understand so these notes start with that type. An induction motor or asynchronous motor is an ac electric motor in which the electric current. Singlephase induction motors i splitphase type ii capacitor start type iii capacitor start capacitor. Motor winding and its types an electrical motor is one kind of machine which is used to change the energy from electrical to mechanical. Introduction to ac motors ac motors electronics textbook. Squirrel cage induction motors are widely used in motor and drive applications.
An induction motor can therefore be made without electrical connections to the rotor. Learn all about induction motors including the working principle of an induction. Ppt induction motor powerpoint presentation free to. Yet small brushed ac motors, similar to the dc variety, persist in small appliances along with small tesla induction motors. Induction motor magnetic circuit showing stator and rotor slots. Understand the principle and the nature of single phase and 3 phase induction machines. Therefore a new term is needed to describe the induction motor.
Various modes of failure were simulated for operating conditions typical of an induction motor drive. Induction motors despite the fact that the threephase motor has more phases than the singlephase motor, the singlephase motor is a much more complex machine. Perform an analysis on induction machines which is the most rugged and the most. When the windings in the stator are energized it induces current in the windings in the rotor this invisible force is call induction, learn about the concept of induction here. It is mostly used in industrial drives because it is very reasonable and vigorous, economical and reliable. An induction motor can be defined as the ac electric motor device in which a power source fed by the alternating current with the help of a primary winding. Most of the motors work on the principle of interaction among the electric current as well as the magnetic field within a wire winding. Several factors which include robustness, low cost and low maintenance have made them popular for industrial applications when compared to dc and other ac motors. In an induction motor, the electric current in the rotor needed to produce torque is obtained via electromagnetic induction. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy. Based on the rotor construction, 3 phase induction motor can be of two types.