Pdf the use of squirrel cage motor for traction has revolutionised the motive power of a locomotive. Slip ring motors with resistor starter have been a standard solution to achieve a kind of soft start, when either reduction of start motor current or torque is required, used for 50 years or so. Induction motors and transformers both im and transformer works on the principle of induced voltage transformer. A woundrotor motor, also known as slip ringrotor motor, is a type of induction motor where the rotor windings are connected through slip rings to external resistance. Y designed to give equal resistance in each phase with special profile of fixed and moving electrodes. Slip ring induction motors slip ring motor starter moflon. Maruthi prasad and others published rotor side control of high power slip ring induction motor using a single. They are especially suitable for heavy load inertia applications. Apr 11, 2017 induction motors generally will have low starting torque compared to dc series motor. Therefore, it is customary to combine them in to a single reactance.
In the case of a squirrel cage induction motor, the rotor is inaccessible and rotor circuit resistance is xed, whereas the woundrotor machines are provided with sliprings by which additional. Slip in electrical induction motors engineering toolbox. Polyphase induction motors are mainly of two types by construction, squirrel cage and woundrotorwith slip rings. Users occasionally inquire as to the feasibility of converting an existing woundrotor moto. Slip ring induction motor fundamentals pnpntransistor. It has a high starting torque when compared to squirrel cage induction motor. There is no difference between squirrel cage and slip ring. When a motor starts to rotate the slip is 100 % and the motor current is at maximum. But in slipring motors a major portion of this heat is shared by the external resistance, in proportion to its resistive value.
Figure shows the disassembled view of an induction motor with squirrel cage rotor. Y need cheap and simple solution of sodium carbonate washing soda. Induction motor as an extension to the available non slip power recovery mechanisms available for. Motor type designation rated output rated speed supply voltages frequency mounting. This article is devoted to slip ring induction motors. Read here to know about the starting arrangement and the role played by the external resistances in obtaining better starting characteristics. The stationary part of the motor is called stator and rotary part of the motor is called rotor. Compared to squirrel cage rotor the rotor construction is not simple. The construction of the slip ring induction motor is exactly similar to the. Ac induction motors are the most common motors used in industrial motion control systems, as well as in. Induction motor seminar ppt, pdf report study mafia.
Advantages and disadvantages of slip ring induction motor. Maximum starting can be attained in the slip ring motor compared to squirrel cage motor by inserting an external resistance in each phase of the rotor circuit and cutting the resistance during starting speeds can be. Sketch of a crosssection of slip rings for an electric motor. The magnetic winding is made by joining coils to form phases. The stator circuit is rated as same in the squirrel cage motor, but the rotor is rated in frame voltage or short circuit current. Squirrel cage wound rotor with slip rings the rotating magnetic field the basic idea of an electric motor is to generate two magnetic fields. With the advent of variablefrequency solidstate power supplies, speed variation can be provided by the more reliable, less expensive squirrelcage motor. These motors are usually started with full line voltage. In this project we are going to start and control the speed of 3phase slip ring induction motor. General purpose slip ring induction motors since 1954 1954 03 general purpose slip ring induction motors as part of our development program, we reserve the right to alter or amend any of the specifications included in this catalog without giving prior notice. Woundrotor motors can be started with low inrush current, by inserting high resistance. The torque speed curves are completely different between an induction motor and slip ring motor. Starting torque of slip ring motor and induction motor. Polyphase induction motors are mainly of two types by construction, squirrel cage and woundrotorwith sliprings.
Slip in electrical induction motors slip is the differentiation between synchronous and asynchronous speed. Calculation table for slip ring induction motor used for crane hoisting application calculation table for slip ring induction motor used for crane hoisting application result contain approximate values for crosschecking only. Our design experience and application expertise have made us a leading manufacturer of high voltage slipring inductionmotors. The slip ring induction motor has two distinctly separate parts, one is the stator and other is the rotor. Free download induction motor seminar ppt, pdf report. Maximum starting can be attained in the slip ring motor compared to squirrel cage motor by inserting an external resistance in each phase of the rotor circuit and cutting the resistance during starting speeds can be adjusted in the case of slip. Dec 19, 2016 the torque speed curves are completely different between an induction motor and slip ring motor.
The rotor winding terminals are connected to three slip rings which turn with the rotor. Pdf design and analysis of drive system with slip ring induction. Operating characteristics of a woundrotor slipring. Liquid speed controllers can be supplied to provide required slip resistance to the slip ring motors for speed variation special sized electrolyte tank and heat exchangers are provided to dissipate the heat energy generated in.
This work has developed a steadystate and dynamic mathematical model of three phase slipring induction motors with external impedance. Pdf rotor side control of high power slip ring induction motor. Slip ring induction motor working principle electrical. These motors square measure usually utilized in textile, chemical and pharmaceutical industrial applications. The slip ring motors in our mebsgr series that are described in the following text are in the ic 411 cooling class, known as surfacecooled or ribbedcooled. In previous articles i have discussed the construction, operation, starting, speed control, and classes of squirrel cage induction motors. How to calculate the slip ring induction motor rotor. The top countries of suppliers are india, china, from which the percentage of slipring induction motor supply is 18%, 81% respectively. Be specially designed for energy saving purpose which is totally enclosed and fancooled type. Low and high voltage three phase induction motors slip ring rotor fixed brushholderm line date. In the case of a squirrel cage induction motor, the rotor is inaccessible and rotor circuit resistance is xed, whereas the woundrotor machines are provided with slip rings by which additional. The slip ring induction motors usually have a phasewound rotor. Adjusting the resistance allows control of the speedtorque characteristic of the motor.
Low and high voltage three phase induction motors slip ring rotor fixed brushholderm. The stator construction is the same in both motors. Slip ring induction motor working principle electrical mastar. A slip ring induction motor can be started with external resistance added in its rotor circuit. Low and high voltage three phase induction motors slipring rotor date. Squirrel cage wound rotor with slip rings the rotating magnetic field. The slipring induction motor the wound rotor or slipring ac machine addresses some of the disadvantages of the cage induction motor, but with the handicap of extra cost and the complexity of brushes and insulated rotor windings. Y available in various sizes for motors upto 5000 kw. Theseindividualrotormagneticfieldsproducea combine. Improve the speed characteristics of slip ring induction motor by. Therefore, a slipring motor can be switched on and off more frequently, compared to a squirrel cage motor.
Photograph your local culture, help wikipedia and win. If you have selected your slip ring motor to limit starting currents you can short out the slip rings and run your motor but the starting torque is reduced unless you use some features on the vfd to boost starting torque. Already since 1927, we are a global manufacturer, supplier, and distributor. The torque produced by the induction motor is directly proportional to induction motor slip. Slip ring induction motorinduction motorsslip ring.
This paper suggests a novel method of motor starting by. A wide variety of slipring induction motor options are available to you, there are 11 suppliers who sells slipring induction motor on, mainly located in asia. Starting torque of slip ring motor and induction motor with. You have most likely difficulties to get a slipring motor replaced when it cant be no longer reworked. Advantages of wound rotor induction motors the main advantage of a slip ring induction motor is that its speed can be controlled easily. It will supply the power necessary to drive the motor by resistance variation. Y requires minimum initial investment and negligible maintenance.
Answer zakeer main use of slip ring in im is to add extra resistance to the motor and to give starting current as well as starting torque, when we use slip ring we have to give these connection to the lrs or grr then only it gets sc. Almost 90% of induction motors have squirrel cage rotors. Electrolytic starter lrs for high power slipring motors. As discussed earlier, a slip ring induction motor is an asynchronous motor, as the rotor never runs in synchronous speed with the stator poles. Slipring motors with resistor starter have been a standard solution to achieve a kind of soft start, when either reduction of start motor current or torque is required, used for 50 years or so.
With the correct value of usually resistance inserted in the rotor circuit, a nearunity relationship between torque and. The top countries of suppliers are germany, china, and hong kong s. This can be used in starting a slipring induction motor, for example. The rotor will constantly be turning to align its magnetic field with the stator field. Dec 19, 2017 in this video you will learn connection of slip ring motor with starter panel now you can join our whatsapp group. This work has developed a steadystate and dynamic mathematical model of three phase slip ring induction motors with external impedance. If the external controller is set at zero resistance, the motor operates almost exactly the same as the squirrelcage motor, since the rotor is shortcircuited. Abb induction motors for the mining industry english pdf leaflet application note.
Slip ring induction motors typically have a phasewound rotor. Slip ring motor conversion to vsd driven standard squirrel cage ac motor by j van niekerk, zest weg group over a number of years slip ring motors have largely been replaced by standard squirrel cage ac induction motors, often in conjunction with ac variable speed drives vsds. Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. The slip ring motor has very little application in industries. How to calculate the slip ring induction motor rotor current and voltage. Based on the construction of the rotor, induction motors are broadly classified in two categories.
The rotor core is made up of steel laminations which have slots to accommodate formed 3single phase windings. Epm electrolytic starter can be used to start slipring motors from 500 kw to 20,000 kw. The most basic ways to control the speed of a slip ring induction motor is either from the. The construction of slip ring induction motor is quite different compared to slip ring induction motor. The most advantage of slip ring induction motor is that motor speed will be controlled simply and has high beginning torsion. The value of slip in induction motor at full load varies from about 6% for small motors to about 2% for large motors. Slip ring induction motor is also known as wound rotor induction motor. But how does external resistance aid in better starting characteristics. Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. Slip of induction motor plays an important role in the operation of the induction motor.
The slip rings brushes allow external resistors to be connected in series with the winding. Abb slipring modular motors abb high voltage induction motors. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. An ac alternating current induction motor consists of a stator and a rotor and the interaction of the currents flowing in the rotor bars and the rotating magnetic field in the stator generates the torque that turns. Search weglowandhighvoltagethreephaseslipringrotor. Search weglowandhighvoltagethreephaseslipringrotorvertical11734748manualenglish.
The starting of threephase wound rotor induction motors by stepped resistances added in the rotor circuit suffers from several problems. Starting of slip ring induction motor explained in an easy. Induction motors generally will have low starting torque compared to dc series motor. How to convert a slip ring motor into squirrel cage motor quora. For applications that demand high starting torques, low starting current, or both, baldor is proud to offer abbs broad line of slip ring induction motors. The construction of the slipring induction motor is exactly similar to the construction of squirrel cage induction motor. Starting and speed control of 3phase slipring induction. What are the applications of a slipring induction motor. Portland slip ring induction motorsbrush holder problems and.
The works of the stator is common in all motor to develop a magnetic field. The basic idea of an electric motor is to generate two magnetic fields. General purpose slipring induction motors since 1954 1954 03 general purpose slipring induction motors as part of our development program, we reserve the right to alter or amend any of the specifications included in this catalog without giving prior notice. In slip ring induction motors the rotor is wound type. Good performance, such as high safety, energy saving, compact design, low noise, little vibration, high torque big breakaway torque, reliable operation, stable running and convenient maintenance. Speed control of wound rotor induction motor using rotor. 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 number of slots and has less turns per phase of a heavier conductor. You have most likely difficulties to get a slip ring motor replaced when it cant be no longer reworked. How to convert a slip ring motor into squirrel cage motor. Differential equations are solved using computer simulation. 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. A wide variety of slip ring motor options are available to you, there are 322 suppliers who sells slip ring motor on, mainly located in asia. Home operating characteristics of a woundrotor slipring induction motor.
Already since 1927, we are a global manufacturer, supplier, and distributor of large slip ring motors up to 15000 kw and,8 kv. Learn more about the construction and operation of a slip ring induction motor. Based on the construction of rotor part the 3phase induction motors are divided into two types. This type of rotor is provided with a 3phase, doublelayer, distributed winding consisting of coils used in alternators. Slip ring motors are the motors of choice whenever high starting torque or low starting current are required. Number of poles, frequencies and synchronous induction motor speed. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. In this example, the slip rings have a brushlifting device and a sliding contact bar, allowing the sliprings to be shortcircuited when no longer required. The slip ring induction motor working in the induction principle. Squirrel cage induction motor vs slip ring induction motor. If the slip ring induction motor is started with all the slip rings or the rotor. Starting of slip ring induction motor explained in an easy manner. Slip ring motor conversion to vsd driven standard squirrel.
1233 867 698 115 1337 1510 1084 659 942 520 1559 1 1060 899 1337 240 791 923 881 1174 401 1502 238 362 337 109 730 1304 945 1349 42 718 1110 1284 864 946 210 599 829 1277 797