A form of braking of an induction motor in which a separate dc supply is used to magnetise the motor. Im6 working principle of induction motor concept of. A pulsating magnetic field is produced, when the stator winding of the singlephase induction motor shown below is energised by a single phase. Induction motor working principle when a threephase stator winding of an induction motor is connected to the ac supply, current starts flowing in the stator conductors. The stator windings at 120 degrees phase from each other are given ac supply and hence a rotating magnetic field is produced in the. Woundrotor induction motor the magnetizing branch can not be neglected i0 may be 40% of ip due to the air gap for motors greater than 2 hp, the magnetization branch can be shifted to the input terminals for a motor running at a slip s, the rotor speed is ns1s this will modify the values of e1, i1, e2 and i2. This article is devoted to slip ring induction motors. Induction motor working principle your electrical guide. In wound rotor motors, rotor circuit connection through slip rings to external. By putting resistance in series with the rotor windings, the starting current can be kept low while mainta. Possibility of adding additional resistance to control speed. Principle operation of three phase induction motor my. Speed control of wound rotor induction motor using rotor. The value of slip in induction motor at full load varies from about 6% for small motors to about 2% for large motors.
Oct 05, 2016 the working principle of a single phase induction motor is based on faradays law of electromagnetic induction. Slip ring motor fundamentals bright hub engineering. Working principle of an induction motor circuit globe. The construction of stator of the induction motor is almost the same as other motors. Slip of induction motor plays an important role in the operation of the induction motor. Learn more about the construction and operation of a slip ring induction motor. Wound rotor with slip rings the rotating magnetic field. Rotor side control of high power slip ring induction motor. Rotor side control of high power slip ring induction motor using a single thyristor. A 400 v, 50hz, induction motor, when started directly from the mains takes 4 times the fullload current and the torque produced is twice the fullload torque. Working principle of an induction motor the motor which works on the principle of electromagnetic induction is known as the induction motor. This is utilized by both the stator windings to work as induction motor to meet mechanical load while, a three. Induction motors have been ruling the industrial world for many decades. The operating principle of a 3 phase induction motor is based on the production of a rotating magnetic field r.
The propulsion system of the bannan line of the taipei mrt comprises an ac induction motor controlled by a variablevoltage variablefrequency vvvf. Crane duty motors, slip ring crane duty motors, squirrel. In a conventional round rotor induction motor the behavior of the machine is only needed to be calculated ov er one pole pi tch. Induction motors the motor housing consists of three parts. Slip ring motor conversion to vsd driven standard squirrel. 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. 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, 1 assistant professor, department of electrical and electronics engineering 2,3,4,5 student, department of electrical and electronics engineering. As discussed earlier, a slip ring induction motor is an asynchronous motor, as the rotor never runs in synchronous speed with the stator poles. Working principle of a single phase induction motor.
Induction motors the singlephase induction motor is the most frequently used motor in the world most appliances, such as washing machines and refrigerators, use a singlephase induction machine highly reliable and economical figure 1 singlephase induction motor. Woundrotor motors can be started with low inrush current, by inserting high resistance. Pdf design and analysis of drive system with slip ring. What are slip rings and why do some motors use them. An electrical motor is an electromechanical device which converts electrical energy into mechanical energy. Speed control of wound rotor induction motor using rotor resistance control aim to use variable resistance in the rotor circuit to control wound rotor induction motor speed theory polyphase induction motors are mainly of two types by construction, squirrel cage and woundrotorwith sliprings. The working principle of the permanent magnet synchronous. The slip ring induction motor has two distinctly separate parts, one is the stator and other is the rotor. They set technical standards in terms of size, performance, economy and reliability. Working principle of a single phase induction motor circuit. The basic idea of an electric motor is to generate two magnetic fields. Working principle of a single phase induction motor a single phase induction motor consists of a single phase winding which is mounted on the stator of the motor and a cage winding placed on the rotor.
Principle operation of three phase induction motor the figure shows the portion of a three phase induction motor and is principle explained below. Our 60 minute guide to motor maintenance is designed to give you, the engineer, all the information you need in industrial electric motor maintenance in a format that is concise, easy to understand and is a point of reference. A form of electric braking of an induction motor obtained by reversing the phase sequence of its any two lines. Slip ring induction motor is made up from wound rotor and squirrel cage induction motor is made up from the squirrel cage rotor. The induction motor slip is usually expressed as a percentage of. Im6 working principle of induction motor concept of slip. The legs at the middle section permit the attachment of. A system of electric braking in which energy is returned to the supply system. In the case of three phase ac alternating current operation, the most widely used motor is a 3 phase induction motor, as this type of motor does not require an additional starting device. The surfacecooling principle in slip ring induction motors ic 411 the standard threephase slip ring induction motor in protection class ip 55 has ic 411 cooling.
This does not involve the power from on rotor side be fed back to the source. Slip ring induction motor power factor control using fuzzy logic controller sivanagappa. Portland slip ring induction motorsbrush holder problems and. Due to this current, a rotating magnetic field of constant amplitude and a constant speed is set up in the air gap between stator and rotor.
Multi phase induction motors types, their working and. The slip ring induction motors usually have a phasewound rotor. 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. 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. The slip ring induction motor working in the induction principle. Nov 27, 2019 thus from the working principle of three phase induction motor, it may be observed that the rotor speed should not reach the synchronous speed produced by the stator. If the speeds become equal, there would be no such relative speed, so no emf induced in the rotor, and no current would be flowing, and therefore no torque would be generated.
Three phase slip ring induction motor my tech info. The rotor will constantly be turning to align its magnetic field with that of the stator field. The rotor of an induction motor can be a squirrel cage. In normal conditions, the slip ring motor functions like a squirrel cage motor. 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. Slip ring induction motor construction, working and its speed. Already since 1927, we are a global manufacturer, supplier, and distributor. The difference is that, in the case of the induction motor, the secondary windings can move due to the rotation of the rotor the secondary winding of the im, the induced voltage in it does not have the same frequency of the stator the primary voltage 3192014 emdii. Slip ring motors are the motors of choice whenever high starting torque or low starting current are required.
Woundrotor motors can be started with low inrush current, by inserting high resistance into the rotor circuit. Ac supply is given to stator windings which is single phase, the current flowing through the winding will produce a magnetic field which is called stator magnetic field. This type of rotor is provided with a 3phase, doublelayer, distributed winding consisting of coils used in alternators. The singlephase stator winding produces a magnetic field that pulsates in strength in a sinusoidal manner. The three phase stator winding gets energized when a three phase supply is given to the stator winding, a rotating magnetic field is produced which revolves round the stator its synchronous speed n. Starting and control of threephase asynchronous motors eaton. Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. The threephase asynchronous motor is the most widely used electric motor worldwide in industrial. A three phase supply is applied to one of the stator windings, a revolving magnetic field is developed in the air gap and this.
But the rotor construction differs with respect to the type of motor. The difference is that, in the case of the induction motor, the secondary windings can move due to the rotation of the rotor the secondary winding of the im, the induced voltage in it does not have the same frequency of the stator the primary voltage 3192014 emdii induction motor design. A, 1 assistant professor, department of electrical and electronics engineering 2,3,4,5 student, department of. Introduction this research study has the impact of the principle of slip power recovery drive particularly to reduce the. Whereas in squirrel cage motor, it is not possible to add any external. Ysalient features y robust and nonflammable construction. Slip ring induction motor power factor control usingfuzzy. Slip power recovery system in three phase slip ring. Slip power recovery system in three phase slip ring induction 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. While slip ring induction motors also known as woundrotor motor. In the induction motors used in lift and hoists, you will see a type of rotor called a slip ring.
A linear induction motor lim is an alternating current ac, asynchronous linear motor that works by the same general principles as other induction motors but is typically designed to directly produce motion in a straight line. Once the motor reaches operating speed, the brushes are lifted via the springs and the slip rings are. Dc motor explained basic working principle how dc motor works. Slip ring induction motor are used where high starting torque is required i. Characteristically, linear induction motors have a finite primary or secondary length, which generates endeffects, whereas a conventional induction. Based on the construction of rotor part the 3phase induction motors are divided into two types. This cooling type corresponds to the design of a surfacecooled motor with a housing featuring cooling fins and an external fan mounted on the shaft. They are especially suitable for heavy load inertia applications. 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. This article encompasses the working principle of slip ring induction motor, construction, speed control, resistance calculation and its applications.
Adjusting the resistance allows control of the speedtorque characteristic of the motor. The propulsion system of the bannan line of the taipei mrt comprises an ac induction motor controlled by a variablevoltage variablefrequency vvvf controller by means of vf technique 2. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. What is the working principle of slip ring induction motor. Severe arcing between the brushes and collector rings. Stator winding can be either star or delta connected depending upon the design. Slip ring induction motor working principle electrical mastar. Y provides smooth and stepless cutting of resistance in rotor circuit of the motor, reducing starting current and increasing starting torque of slipring induction 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. Principle operation of three phase induction motor my tech info. The torque produced by the induction motor is directly proportional to induction motor slip.
Our design experience and application expertise have made us a leading manufacturer of high voltage slipringac motor construction. Starting of slip ring induction motor explained in an easy. A single phase induction motor has two types of rotor. Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. An induction motor or asynchronous motor is an ac electric motor in which the electric current. The rotor core is made up of steel laminations which have slots to accommodate formed 3single phase windings. The working principle of a single phase induction motor is based on faradays law of electromagnetic induction. In the induction motor rotor always rotates speed less than synchronous speed. These types of motors are known as selfstarting induction motors. The electromagnetic induction is the phenomenon in which the electromotive force induces across the electrical conductor when it is placed in a rotating magnetic field.
The rotor of an induction motor can be a squirrel cage rotor or wound. Similar is the operation of the induction motor in parallel with a synchronous motor serving as a. Dec 19, 2017 in this video you will learn connection of slip ring motor with starter panel now you can join our whatsapp group. What is the operating principle of a 3 phase induction motor. Menzel slip ring motors, also called wound rotor motors, are available in all current motor cooling and protection types for lowvoltage from 75 kw as well as medium and high voltage up to 15000 kw. The 3phase set of currents, each of equal magnitude and with a phase. Learn the working principle and applications of a squirrel cage. Advantages of slip ring induction motor it has high starting torque and low starting current. An induction motor can therefore be made without electrical connections to the rotor.
A pulsating magnetic field is produced, when the stator winding of the singlephase induction motor shown below is energised by a single phase supply. Slip ring induction motor working principle electrical. An induction motors rotor can be either wound type or squirrelcage. The 3 phase induction motor works based on faradays law that an emf is induced in the circuit due to the rate of change of magnetic flux through the circuit.
In previous articles i have discussed the construction, operation, starting, speed control, and classes of squirrel cage induction motors. Nov 03, 2019 an induction motor also known as an asynchronous motor is a commonly used ac electric motor. 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. Construction and working of 3 phase induction motor on ship. The major difference between them is that transformer is static in nature i. The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements. Hi friends, in this article i am describing the importance of slip in induction motor and hoping you will find it informative and useful. Slip ring induction motor are used where high starting torque is. Induction motors generally will have low starting torque compared to dc series motor. Single phase induction motor the engineering projects. Advantages and disadvantages of slip ring induction motor.
915 1433 1532 1005 1086 98 1436 1386 1067 1499 1003 782 467 1498 571 238 664 529 1440 1180 1426 1442 452 1381 217 947 5 339 702 986 106 388 558 93 1348 218 46 234 701 883