Portland slip ring induction motorsbrush holder problems. In slipring induction motors, the shape of the torquespeed curve can be changed by introducing extra resistance into the rotor of the motor. Slip ring induction motor fundamentals pnpntransistor. Fault identification of 3phase slip ring induction motor. Scribd is the worlds largest social reading and publishing site. Slip ring motor conversion to vsd driven standard squirrel. The motor which employing the wound rotor is known as a slip ring induction motor or phase wound motor. Carbon brush performance on slip rings mining electrical. Slip power recovery system in three phase slip ring induction. The singlephase stator winding produces a magnetic field that pulsates in strength in a. Already since 1927, we are a global manufacturer, supplier, and distributor of large slip ring motors up to 15000 kw and,8 kv. The works of the stator is common in all motor to develop a magnetic field. A wound rotor, has a 3phase winding similar to the stator winding. 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standard squirrel cage ac motor by j van niekerk, zest weg group over a number of years slip ring motors have largely been replaced by standard squirrel cage ac induction motors, often in conjunction with ac variable speed drives vsds.
Squirrel cage motors have a rotor with short circuited bars whereas slipring motors have wound rotors having three windings each connected in star. 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. Vem threephase motors with slipring rotor combine the general benefits of. This type of rotor is provided with a 3phase, doublelayer, distributed winding consisting of coils used in alternators. At noload, the slip is nearly zero slipring motor is expensive, as are its controls, compared to a squirrel cage motor. The construction of a stator is the same for both the squirrel cage and slip ring induction motor. Adjusting the resistance allows control of the speedtorque characteristic of the. Mechanical design of slip ring motor srsh 2 to 315 m. Free download induction motor seminar ppt, pdf report. But in an induction motor only the stator winding is fed with an ac supply. Smooth starting of slip ring induction motors article pdf available in ieee transactions on energy conversion 124. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable.
Some sections may explain explicitly between the three configurations, but have different requirements for each. Terms used in wound rotor slip the difference between a motors synchronous speed and its speed at full load. Slipring induction motor also known as rotor resistance start motor. This can be used in starting a slipring induction motor, for example. An operating and maintenance manual, a terminal plan and a safety data sheet. The slip ring or wound rotor motor is an induction machine where the rotor comprises a set of coils that are terminated in sliprings to which external impedances can be connected. Stator winding can be either star or delta connected depending upon the design. The slip power may be utilized again using slip recovery. The value of slip in induction motor is can never be zero. 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. Since then a lot of improvement has taken place on the design of these two types of induction motors.
Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Slip ring motors are the motors of choice whenever high starting torque or low starting current are required. General purpose slipring induction motors product catalogue. When a motor starts to rotate the slip is 100 % and the motor current is at maximum. Squirrel cage induction motor slip ring induction motor 2. Pdf three phase slip ring induction motor drive with slip power. Starting andcontrol of slipring 5 electrical engineering book. A slipring motor also requires a larger space for the motor and its controls. Abb library is a web tool for searching for documents related to abb products and. Sketch of a crosssection of slip rings for an electric motor.
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. Pdf rotor side control of high power slip ring induction motor. Slip ring induction motor are used where high starting torque is required i. Ppt induction motor powerpoint presentation free to. How to convert a slip ring motor into squirrel cage motor quora. For load sharing to take place automatically, the motor speed should drop considerably as the load increases and this is ensured by using a motor having a high fullload slip, say for example 10%. A single phase induction motor has two types of rotor. Thyristor, slip ring induction motor srim, stator and rotor, polyphase motor, universal. The slip ringsbrushes allow external resistors to be connected in series with the winding. Slip ring induction motor is also known as wound rotor induction motor.
This means that the state of the carbon brushes and the slip ring rotor can be monitored, and cleaning can take place. Is there any advice or similar applications out there that could be helpful. Three phase slip ring induction motor my tech info. Vibrations amplifications on the unsupported shaft extensions of the rotors. Dec 19, 2016 this motor is much heavier than the 22kw slip ring motor and resistor bank so the crane had to be rerated as well. Safe area motors motors for general application cga1d standard squirrel cage tefc motors. Portland slip ring induction motorsbrush holder problems and. Pdf this work has developed a steadystate and dynamic mathematical model of three phase slipring induction motors with external impedance find, read. Therefore slip ring induction motors are generally employed where load requires high starting torque or good speed control. 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. What are the applications of a slipring induction motor. The slip ring induction motor has two distinctly separate parts, one is the stator and other is the rotor.
Apr 11, 2017 induction motors generally will have low starting torque compared to dc series motor. Mechanical design of slipring motor srsh 2 to 315 m. Lecture 6 three phase induction motors cairo university. A wound rotor or slip ring motor has a 3phase winding, similar to the stator. In slip ring induction motors, the shape of the torquespeed curve can be changed by introducing extra resistance into the rotor of the motor. 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. 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. Maruthi prasad and others published rotor side control of high power slip ring induction motor using a single. The slip ring motor has very little application in industries. Induction motors generally will have low starting torque compared to dc series motor. The stator is the same as is used with a standard squirrel cage motor. This can be used in starting a slip ring induction motor, for example. Induction motor seminar ppt, pdf report study mafia.
Oct 04, 2017 3 phase motor with resistance type starter. A woundrotor motor, also known as slip ring rotor motor, is a type of induction motor where the rotor windings are connected through slip rings to external resistance. Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. It also requires meticulous and periodic maintenance of the brushes, brush gear, sliprings, external rotor resistances etc. The slip ring induction motors usually have a phasewound rotor.
This motor is much heavier than the 22kw slip ring motor and resistor bank so the crane had to be rerated as well. If the motor slip is known, the rotor speed can be expressed by the equation. The main difference in a slip ring induction motor is on the rotor construction and usage. This method depends on having a huge starting torque and a small starting current and slip. The slip ring rotor was developed after a decade or so. Slip ring motors electrical calculations and induction. Slip in electrical induction motors engineering toolbox. Some sections may explain explicitly between the three configurations. Slipring induction motor connection and testing youtube. Rotor side control of high power slip ring induction motor using a.
Slip ring motor fundamentals bright hub engineering. Severe arcing between the brushes and collector rings. A squirrel cage motor is thus preferred to a slipring motor. The material pairing used for the slip ring contact system is normally bronzemetal graphite. The slip ring rotor chamber has two modification openings. The stationary part of the motor is called stator and rotary part of the motor is called rotor. The scheme is somewhat analogous to a primitive kramer system, where a dc motor is coupled to the induction motor shaft and is fed by the rectifier slip power through a diode rectifier. Construction of three phase induction motor electrical4u. May, 2017 with the advent of variablefrequency solidstate power supplies, speed variation can be provided by the more reliable, less expensive squirrelcage motor. Aim to understand the function of the 3phase slip ring induction motors and. Fullload slip varies from less than 1 % in high hp motors to more than 56 % in minor hp motors.
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 supply from the rotor of the other slip ring motor with external resistance mounted on its rotor. Advantages and disadvantages of slip ring induction motor. Sliprings are made of high quality phosphorbronze and are of moulded construction. The rotor of the slip ring induction motor is also cylindrical or constructed of lamination. 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. Figure 4 shows the torquespeed characteristics of slip ring induction motor in modified static kramer drive. Slip ring or phase wound induction motor squirrel cage induction motor construction is complicated due to presence of slip ring and brushes construction is very simple. We start the slip ring threephase induction motor by inserting resistances so, the stator winding of slip ring induction motor can be connected either in star or delta. 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. The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. Aim to understand the function of the 3phase slip ring induction motors and how it is work when its characteristic. All motors comply with the following indian and international standards.
Number of poles, frequencies and synchronous induction motor speed. General purpose slipring induction motors cantoni motor pdf. Percent slip is a way to measure the speed performance of an induction motor. Therefore slip ring induction motors are generally employed where load. Features and benefits the slipring motor is an induction machine where the rotor comprises a set of coils that are terminated in slip rings to which. The rotor core is made up of steel laminations which have slots to accommodate formed 3single phase windings. The rotor is wound for the same number of poles as that of the stator.
Dec 01, 2017 slipring induction motor also known as rotor resistance start motor. It consists laminated cylindrical core which has a semiclosed slot at the outer periphery and carries threephase insulated winding. Lot of research work has been carried out to improve its power factor and to achieve suitable methods of speed control. The rotor terminals are connected to three slip rings which turn with the.
Slip ring induction motor working principle electrical mastar. Feb 20, 2014 terms used in wound rotor slip the difference between a motor s synchronous speed and its speed at full load. Starting of slip ring induction motor explained in an easy. Generally we all are know induction motor is most widely used motor in industrial.
The brush holders are double boxtype brush holders. Slip in induction motor is the relative speed between the rotating magnetic flux and rotor expressed in terms of per unit synchronous speed. 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. According to the labelled notation a represents stator b rotor c bearing shields d fan e venti lation grill and f terminal box. Learn more about the construction and operation of a slip ring induction motor. We have sent the motor to our motor guy to refurbish and interconnect the rotor windings. The material pairing used for the slipring contact system is normally bronzemetal graphite. Users occasionally inquire as to the feasibility of converting an existing woundrotor moto. Fault identification of 3phase slip ring induction motor free download as powerpoint presentation. With the advent of variablefrequency solidstate power supplies, speed variation can be provided by the more reliable, less expensive squirrelcage motor. As discussed earlier, a slip ring induction motor is an asynchronous motor, as the rotor never runs in synchronous speed with the stator poles. Slip ring motors are normally used where additional torque is required to overcome the inertia of the. Three phase induction motors electric motors bharat bijlee. Short out the slip rings and the motor will run just like a standard induction motor.
Starting torque of slip ring motor and induction motor with. The induction motor stator resembles the stator of a revolving field, three. Slip rings a conductive device attached to the end of a wound rotor that conducts current to the brushes. In a dc motor, supply is needed to be given for the stator winding as well as the rotor winding. In the induction motors used in lift and hoists, you will see a type of rotor called a slip ring rotor, whereas in most of the other applications you.
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