Three phase slip ring induction motor drive with slip. 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. Generally we all are know induction motor is most widely used motor in industrial. C series motors but this disadvantages of the induction motor can be overcome by slip ring induction motor. The slip ring induction motor has two distinctly separate parts, one is the stator and other is the rotor. The slipring induction motor is not as simply constructed as the cage induction motor, but it is possible to control its starting performance and speed by connecting external equipment commonly resistors into the rotor circuit via sliprings. Squirrel cage induction motor squirrel cage induction motors are usually used in various industrial applications. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. 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.
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. It is in these circumstances that slip ring induction motors are used, as they produce high starting torque fig. Slip rings a conductive device attached to the end of a wound rotor that conducts current to the brushes. Slip in induction motor is the relative speed between the rotating magnetic flux and rotor expressed in terms of per unit synchronous speed. Vem threephase motors with slipring rotor combine the general benefits of. Here, we study how the use of rotor slip rings connected to a rheostatan adjustable resistorcan be used as one such method. Slipring induction motor also known as rotor resistance start motor. In this type of induction motors, the rotor comes with the separate winding section as similar to stator of the motor. Normal induction motors, or squirrel cage type motors, produce a very low starting torque, and for some applications, this low starting torque will cause huge problems. So, this motor is used in applications like lifts, pumps, mills where we require high starting torque. The slip ring motor has very little application in industries. 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.
Slipring induction motors are used for systems specifying limitations on starting current, for high inertia drives and for frequent starting. The rotor winding terminals are connected to three slip rings which turn with the rotor. Slip ring induction motor fundamentals pnpntransistor. If the slip ring induction motor is started with all the slip rings or the rotor. Rarely 5% 10% slip ring motors are used in industries because it has several disadvantages like it required. Pdf three phase slip ring induction motor drive with.
An induction motors rotor can be either wound type or squirrelcage type. What is the function of slip ring in 3 phase induction motor. When starting industrial induction motors, different methods are often employed to prevent damages to the motor windings due to high starting currents. This means that the state of the carbon brushes and the slip ring rotor can be monitored, and cleaning can take place. The brush holders are double boxtype brush holders. Induction motors generally will have low starting torque compared to dc series motor.
The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. Three phase slip ring induction motor my tech info. Slipring induction motor connection and testing youtube. Rotor side control of high power slip ring induction motor using a. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Slip ring induction motor application slip ring induction motor provides high starting torque.
The difference of squirrel cage and slip ring induction motor is mainly on torque, speed, slip, resistance and reactance. Slip ring motors are the motors of choice whenever high starting torque or low starting current are required. Therefore slip ring induction motors are generally e. Electrical interview questions which motor is best. 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. In squirrel cage induction motor scim the rotor is short circuited and contai. The slip ring motor is used in applications where the application requires varying the speed of the motor. Makwana and others published three phase slip ring induction motor drive with slip power control analysis for different load torque using microsoft excel as software. As its name indicates stator is a stationary part of 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. In cranes, hoists and tractions basically slip ring induction motor is designed to overcome the drawback in squirrel cage induction motor which is low starting torque. 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%. The resistance of this motor depends upon the slip, and independent of the torque. Fault identification of 3phase slip ring induction motor.
Three phase induction motors electric motors bharat bijlee. They are especially suitable for heavy load inertia applications. The terminals of the rotor windings of the slipring motors. An induction motor can therefore be made without electrical connections to the rotor. Wound rotor induction motors with three rotor slip rings have been used in adjustable speed drives for many years. Mechanical design of slipring motor srsh 2 to 315 m. What is slip ring induction motor practical explanation. Motor runs smoothly as the magnetic hum is reduced b. Free download induction motor seminar ppt, pdf report. Dosto maine aapse share kiya hai ki slip ring motor kayse kam karta haiy ummind haiy ki ye video aapko pasand aayega app subscribe technical gyan.
The tendency of the rotor teeth to remain under the stator teeth due to direct magnetic attraction is reduced. The rotor can be wound a threephase star or delta winding, distributed winding, wound for the same as that of the stator of the motor. The rotor core is made up of steel laminations which have slots to accommodate formed 3single phase windings. A stator winding is placed in the stator of induction motor and the three phase supply is given to it. In the slipring motor, the effective rotor resistance is increased by adding external resistance through the slip rings. We know that a motor uses an external high resistance circuit for producing high starting torque. It can improve mechanical performance, simplify system operation and eliminate damageprone wires dangling from movable joints. The value of slip in induction motor is can never be zero. 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. Therefore slip ring induction motors are generally employed where load requires high starting torque or good speed control. Rotor induction motor an overview sciencedirect topics. Pdf three phase slip ring induction motor drive with slip power.
The aim behind the development of the project is to limit the current at starting of motor and to develop the high starting torque. Most of the application of industrial as well as domestic are this type of induction motor. Terms used in wound rotor slip the difference between a motors synchronous speed and its speed at full load. Pdf rotor side control of high power slip ring induction motor. Fault identification of 3phase slip ring induction motor free download as powerpoint presentation. A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. Wound rotor induction motors with three rotor slip rings have been used in adjustable speed drives for many. There are different methods of starting of 3phase slip ring induction motor. An887, ac induction motor fundamentals microchip technology. The mechanism employed here is to control the speed via a single thyristor acting as an onoff switch at the rotor side of this slip ring induction motor. Slip ring motors contents product description 62 overview of technical data 64 motor selection data series srspr variablespeed slip ring motors, continuous duty s1 65 series shsph version for crane applicationsiron and steel works, duty types s3, s4s5 67 bearings 626 terminal boxes 631.
Slip ring induction motor working principle electrical. A slip ring can be used in any electromechanical system that requires rotation while transmitting power or signals. Stator winding can be either star or delta connected depending upon the design. All motors comply with the following indian and international standards. Generally, induction motor provides low starting torque as compared to d. Portland slip ring induction motorsbrush holder problems. In an induction motor, torque is equal to the power crossing the air gap divided by the synchronous mechanical speed. The winding of rotor is 3phase winding one end is shorted to form the nutral point, it can be star or delta. Slip ring motors are motors that have a winding in the stator of the motor, like regular motors, and a winding on the rotor, the rotating part of the motor. Lecture 6 three phase induction motors cairo university. Power control analysis for different load torque using. If the motor slip is known, the rotor speed can be expressed by the equation. The slip ringsbrushes allow external resistors to be connected in series with the winding.
The rotor of the slip ring induction motor is also cylindrical or constructed of lamination. Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. Squirrel cage motors have a rotor with short circuited bars whereas slipring motors have wound rotors having three windings each connected in star. It is logical that the least expensive, lowest maintenance type. Starting of slip ring induction motor explained in an easy. Safe area motors motors for general application cga1d standard squirrel cage tefc motors. The squirrel cage induction motor is the most popular type of ac motor. What are the applications of a slipring induction motor. Slip ring motor 5 frame size rated power duty cycle rated speed stator current rotor voltage rotor current pn kw % ed nn min1 i1 a u2 v i2 a 3en315sg 04 90 100 1478 171 310 177. The rotor circuit resistance has significant impact on starting torque, the speed at which the breakdown torque occurs, and the slip during the normal running operation. The material pairing used for the slipring contact system is normally bronzemetal graphite. An operating and maintenance manual, a terminal plan and a safety data sheet. Advantages and disadvantages of slip ring induction motor. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain.
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