It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. I will tell you about the construction of wound rotor induction motor in the first section. This article presents an understanding of what wound rotor motors are, how they work. Jan 15, 2014 the video highlights details regarding the construction of three phase induction motor.
Apr 12, 2020 ppt threephase induction motor electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. Slip ring induction motor fundamentals pnpntransistor. A 3 phase induction motor can be used for different applications with various speed and load requirements. The 3phase set of currents, each of equal magnitude and with a phase.
This article is devoted to slip ring induction motors. Singlephase induction motor threephase induction motor singlephase induction motor there are probably more singlephase ac induction motors in use today than the total of all the other types put together. These slip rings allow for speed and torque control and are the defining feature. Construction, types and principle of operation of 3phase induction motors. Learn more about the construction and operation of a slip ring induction motor. The shaft of the induction motor is supported on two bearings at each ends to ensure free rotating within the stator and. Squirrel cage wound rotor with slip rings the rotating magnetic field. In the slip ring type,the rotor consists of three phase winding similar to that of the stator winding. In squirrel cage induction motors the rotor is simplest and most rugged in construction.
The slip rings brushes allow external resistors to be connected in series with the winding. In slip ring induction motors the rotor is wound type. Some changes in the stator may be encountered when a slip ring motor is used in a cascaded system, as the supply for the slave motor is controlled by the. Brushes are used to take connection from these slip rings at starting high external resistances are usually included to improve starting torque and reduce starting current. Squirrel cage induction motor vs slip ring induction motor. Slip ring induction motor application slip ring induction motor provides high starting torque.
The construction of stator of the induction motor is almost the same as other motors. There are two types of induction motors, one with wound type rotor, also called slip ring motor and another one with squirrelcage rotor. Vem motors gmbhframe 2 315 low voltage410 pole various duty cycles. Also know about the special constructional features of the rotor. There is no difference between squirrel cage and slip ring motors. This document is highly rated by electrical engineering ee students and has been viewed 2470 times. Wound rotor induction motors with three rotor slip rings have been used in. Electric motor electric motor construction of induction motors. It is logical that the least expensive, lowest maintenance type motor should be used most often. The rotor is wound for the same number of poles as in the stator and the free end of these windings are connected to three insulated slip.
Type of construction im 1001 im b3 type of construction im 3011 im v1 motor shaft heigh nos of poles drive end non drive end bearing lubrication lubrication. The stator construction is the same in both motors. A motor rating of 10 horse power, 415 volts with 1440 rpm and 4pole is selected for design problem and an. Construction of squirrel cage induction motor explained. Almost 90% of induction motors have squirrel cage rotors. Slip ring induction motor or wound induction motor or phase wound induction motor.
So, it is not advised to start a slip ring induction motor with its rotor terminals shorted. This work is introducing the designing of new three phase squirrel cage induction motor with an objective of getting good efficiency. The stator frame consists of laminations of silicon steel, usually with a thickness of about 0. Slip rings induction motor provides some advantages like provides high starting torque, low starting current and it improves the power factor. Sketch of a crosssection of slip rings for an electric motor. Slip ring rotor or wound rotor or phase wound rotor. Construction an induction motor consists essentially of two main parts. The slip ring rotor chamber of the ic 411 slip ring induction motor is separated by what is known as a labyrinth seal, which prevents contamination from coal dust. Generally, induction motor provides low starting torque as compared to d. Diagnostics of rotor and stator problems in industrial induction motors by fang duan b. Jun 01, 2018 slip in induction motor is the relative speed between the rotating magnetic flux and rotor expressed in terms of per unit synchronous speed. A slip ring motor gest a complex construction owing to the use of slip. Squirrelcage rotor almost 90 per cent of induction motors are squirrelcage type, because this type of rotor has the simplest and most rugged construction imaginable and is almost indestructible.
The construction is complicated and the presence of brushes and slip ring makes the motor more costly the construction is simple and robust and it is cheap as compared to slip ring induction motor this motor is rarely used only 10 industry uses slip ring induction motor due to its simple construction. Read online slip ring induction motors basics book pdf free download link book now. Induction motors are classified into squirrel cage and slip ring induction motors according to the type of motors used in them. Almost 90 percentage of induction motors are squirrelcage type, because this type of rotor has the simplest and most rugged construction imaginable and is almost indestructible. The main difference in a slip ring induction motor is on the rotor construction and usage. Wound rotor motors also can develop high starting torque at standstill while maintaining low inrush.
A squirrelcage motor with this type of rotor construction is called nemadesign class d. Motor nameplate informationthe service factor on a motor nameplate indicates how much above the nameplate rating a motor can be continuously loaded. The slip ring induction motor is shown in the figure below. Motors employing this type of rotor are widely known as phasewound motors or wound motor or slip ring motors. Compared to squirrel cage rotors, wound rotor motors are expensive. What is the difference between a slip ring and a squirrel. Wound rotor tecowestinghouse motor company, a world. The construction of the slipring induction motor is exactly similar to the construction of squirrel cage induction motor. The function of the slip rings and the brushes is to provide a means of connecting external resistors in the rotor circuit. In my last article, we have discussed everything on squirrel cage induction motors including its disadvantages. Long motor life is ensured with the use of external resistor banks or liquid rheostats that dissipate heat buildup generated during motor startup.
We can react very quickly due to a comprehensive stock of slip ring motors in a power range up to 15000 kw. A 3 phase induction motor has two main parts i stator and ii rotor. 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. It is mostly used in industrial drives because it is very reasonable and vigorous, economical and reliable. As discussed earlier, a slip ring induction motor is an asynchronous motor, as the rotor never runs in synchronous speed with the stator poles. Rotor in slip ring type consists of heavy aluminum or copper bars shorted on both ends of the cylindrical rotor. Feel free to visit our article on the types of ac motors to learn more. Td 216 general puropse slip ring induction motors nieuw 1. This final thesis will mostly be dedicated to induction motors but also to synchronous permanent magnet and reluctance motors. Properly, it is an electric communication device that permits the flow of energy among two electrical rotating elements in a motor. Construction of induction motor the three phase induction motor is a preferable type of motor. Induction motors have been ruling the industrial world for many. This means that the state of the carbon brushes and the slip ring rotor can be monitored, and cleaning can take place.
And in the previous article on types of electrical motors, we have classified induction motors based on the type of rotor used. Construction of induction motor electrical edition. The rotor and stator are separated by an air gap which allows free rotation of the rotor. Rotor as the name suggests it is a rotating part of an electrical machine, in which current is induced by transformer action from rotating magnetic field. Cheap copare to slipring im maintainance is easy cost is less compare to slipring im can use at explosive area starting torque is low compare to slip ring im application. We can add external variable resistance to the rotor of this type of motor. A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. Download slip ring induction motors basics book pdf free download link or read online here in pdf. The basic idea of an electric motor is to generate two magnetic fields. Motor, 3 phase induction motor construction, induction motor construction, working ppt, induction motor construction video, induction motor construction and working pdf. This can be used in starting a slipring induction motor, for example. The two brushes are connected to a single phase starconnected rheostat as. Slip ring motor fundamentals brighthub engineering. But the rotor construction differs with respect to the type of motor.
Most of the application of industrial as well as domestic are this type of induction motor. Starting of slip ring induction motor explained in an easy manner. Depending upon the type of rotor construction used the three phase induction motor are classified as. In this example, the slip rings have a brushlifting device and a sliding contact bar, allowing the slip rings to be shortcircuited when no longer required. Based on the construction of the rotor, induction motors are broadly classified in two categories. C series motors but this disadvantages of the induction motor can be overcome by slip ring induction motor. Slip ring induction motor working principle electrical. Design and analysis of drive system with slip ring induction motor for electric traction in india article pdf available in international journal of power electronics and drive systems 53. The slip ring motor has very little application in industries. The construction of a stator is the same for both the squirrel cage and slip ring induction motor. One of the advantages of the slip ring motor is that resistance may be inserted in the rotor circuit to obtain high starting torque at low starting current and then cut out to obtain optimum running conditions. One of the main classifications of asynchronous motors are the slip ring induction motors. The rotor of the slip ring induction motor is also cylindrical or constructed of lamination. Its starting torque is somewhat inferior to that of a d.
Ppt threephase induction motor electrical engineering. But in an induction motor only the stator winding is fed with an ac supply. A slip ring can be used in any electromechanical system that requires rotation while transmitting power or signals. The slip ring rotor chamber has two modification openings. How are squirrel cage induction motors different from slip. The construction of a stator for both of the kinds of three phase induction motors is identifcal, and is discussed briefly below. A wound rotor induction motor has a stator like a squirrel cage induction motor, but a rotor with insulated windings brought out via slip rings and brushes however, no power is applied to the slip rings. The slip rings are mounted on the shaft with brushes resting on them. Motors employing this type of rotor are variously known as phasewound motors or wound motors or as slip ring motors. The rotor winding terminals are connected to three slip rings which turn with the rotor. Wound rotor induction motors ac motors electronics.
Types, construction and principle of operation, 3 phase induction motor, general phasor diagram, equivalent circuit, power and torque. Basic construction of 3phase ac induction motors you should. Ppt induction motor powerpoint presentation free to. The rotor of three phase ac induction motor is different for the slip ring and squirrelcage induction motors. Do you know what happens to slip ring motor when external resistance is added.
It is also called asynchronous motor because it does not run at a synchronous speed. Design and analysis of drive system with slip ring induction motor for electric traction in india. The construction of slip ring induction motor is quite different compared to other induction motor. Stator winding can be either star or delta connected depending upon the design. Basic construction and operating principle like most motors, an ac induction motor has a fixed. Slip ring induction motor working principle electrical mastar. Squirrel cage induction motor slip ring induction motor 2. Learn a brief history of the electrical power systems construction.
The anatomy and operation of these motors will be explored, as well as the specific. The rotor is the rotating part of the induction motor and is mounted on the shaft of the motor to which any mechanical load can be connected. Diagnostics of rotor and stator problems in industrial. The rotor is separated from the stator by a small airgap which ranges from 0. The stator of slip ring induction motor is very much the same as that of the squirrel cage induction motor, but the construction of its rotor is very much different. The value of slip in induction motor is can never be zero. Designing of three phase squirrel cage induction motor for. Three phase slip ring induction motor my tech info.
Induction motor seminar ppt, pdf report study mafia. The video tutorial is essentially a part of the basic electrical and electronics engineering. By putting resistance in series with the rotor windings, the starting current can be kept low while mainta. Free download induction motor seminar ppt, pdf report.
What makes the wound rotor motor a unique induction machine is its rotor. Pdf design and analysis of drive system with slip ring induction. Depending upon the type of rotor construction used the three phase induction motor are. The induction motor are of two types based on the construction of rotor. Jul 09, 20 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. Also appreciate the external resistances and carbon brush arrangements with the slip rings and advantages of slip ring induction motor. Portland slip ring induction motorsbrush holder problems and. The brushes are connected to the variable resistor.
What are the advantages of slipring induction motor. So, this motor is used in applications like lifts, pumps, mills where we require high starting torque. Pdf the use of squirrel cage motor for traction has revolutionised the. Pdf design and analysis of drive system with slip ring. 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. By far the most commonly used ac motor is the induction motor. A wound rotor or slip ring motor has a 3phase winding, similar to the stator. Wound rotor induction motor the engineering projects. Because of the large rotor resistance, this motor has a pullout torque occurring at a high slip, and its starting torque is quite high. For an induction motor with p polesand f frequency, slip for induction motors a very important parameter is the slip of the motor the slip, s, defines the relative speed difference between synchronous speed and rotor speed and is given by. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain.
Almost 80% of the mechanical power used by industries is provided by three phase induction motors because of its simple and rugged construction, low cost, good operating characteristics, the absence of commutator and good speed regulation. In the second section, i would be throwing light on the operation and working principle of wound rotor induction motor. When motor attains normal speed, three brushes are short circuited. Lamination is necessary since a voltage is induced along the axial length of the steel as well as in the stator conductors. Compared to squirrel cage rotor the rotor construction is not simple. The slip ring commutator construction is, consists of immobile graphite otherwise brush which is known as metal contact which wipes on the exterior diameter of a revolving metal ring. The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. The rotor will constantly be turning to align its magnetic field with that of the stator field. Typical induction motor rotors the magnetic field generated in the stator induces an emf in the rotor bars. Oct 10, 2016 a wound rotor induction motor is also known as slip ring induction motor. The stator separate from rotor by small air gap have ranges from 0. A wound rotor induction motor is also known as slip ring induction motor.
Construction of three phase induction motor electrical4u. Control of motorcharacteristics by squirrelcage rotordesign. Their sole purpose is to allow resistance to be placed in series with. What is the working principle of slip ring induction motor. Electric motor construction of induction motors britannica.
Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. In turn, a current is produced in the rotor bars and shorting ring and another magnetic field is. Squirrel cage rotor wound type rotor or slip ring type rotor squirrel cage rotor in this type. Rotor induction motor an overview sciencedirect topics. All books are in clear copy here, and all files are secure so dont worry about it. Nov 27, 2019 the three phase induction motor is the most widely used electrical motor. Slip ring induction motor is made up from wound rotor and squirrel cage induction.
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