Based on this example the principle of an induction motor is explained. Topics which are covered here: Slip ring induction motor application, construction, working principle, advantages and disadvantages, speed control of slip ring induction motor, the difference between Slip ring I.M and Squirrel cage I.M.
Principle of Operation. Rayapureddi prasanth. One of the important advantages of this motor is that it is self starting. For a full-load operating slip of 3 per Rotor of Three Phase Induction Motor. Its synchronous speed with a 50 Hz supply is therefore 60 f/p, or 1500 rpm. It eliminates the sparking issues and reduces the overall motor cost. Where R 2 and X 2 are the rotor resistance and inductive reactance at starting respectively, E 2 is the rotor induced EMF. The stator has windings that produce a magnetic field, and windings on the rotor cut this field and induce a current in the rotor windings. Advantages of Squirrel-Cage Induction Motors. 1. a 3 phase supply is given to the stator winding it sets up a rotating magnetic field in This complete article is for you. AC Machines: Working of Squirrel cage Induction Motor Topics discussed:1.
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. The working principle of these motor was depending on Coulombs law. But the rotor construction differs with respect to the type which is specified above. Because of various advantages like low initial current, high starting torque, and improved power factor, it is used in applications that require high torque, cranes, and elevators. Squirrel cage motors maximize electromagnetic induction by utilizing rotor bars to interact with the stators EMF. Induction Motor: This is a small industrial HP Squirrel-Cage Induction Motor which you have to parameterize. According to the rotor structure: squirrel cage asynchronous motor, wound asynchronous motor; Second, the working principle of asynchronous motor. The construction of three phase induction motor. Reply. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. The asynchronous motor is composed of two basic units: a fixed stator and a rotating rotor. They consist of two main components, the outside stator, and the inside rotor, which are separated by a small air gap. Here in this equation, the starting torque of the induction motor is proportional to the rotor resistance R 2.. Hence single phase induction motors are not self starting. Such a magnetic field acting on squirrel cage rotor cannot produce starting torque needed for motor. Most of the motors used in industry are induction motors. A double squirrel cage rotor is shown in the figure. Induction Motor Working Principle. A 3 phase induction motor has two mainq parts (i) stator and (ii) rotor .The rotor is separated from the stator by a small air-gap which ranges from 0.4 mm to 4 mm, depending on the power of the motor. In slip ring induction motors the rotor is wound type. First, let me explain to you how a squirrel cage induction motor works? If you want to know about the slip ring induction motor. Star Star Delta starter of squirrel cage rotor Induction motor. Squirrel cage rotor of the induction motor. What is Squirrel Cage Induction Motor? (i) They are more robust and cheaper.
2. There are numerous types of motor nowadays have been invented. Otherwise, the squirrel cage induction motor is more preferred over slip-ring induction motor. Structure of asynchronous motor. nice information really good information keep up the good work. Working of Slip Ring Induction Motor. Wound rotor motors are a specialized type of AC motor and work in much the same way that other induction motors function. An induction motor has 2 main parts; the Stator and Rotor (Fig:1). 
Stator winding is modified or split into two parts, to make it self start. (This motor is one phase since it is so small.) A double squirrel cage induction motor consists of a rotor which has two independent cages one above the other in the same slot. The slip ring motor has very little application in industries. Aluminum bars would be molded on the slots and they will be short-circuited at the end rings. In modern induction motors, the most common type of rotor has cast-aluminum conductors and short-circuiting end rings. Answer (1 of 9): A slip ring induction motor (a.k.a. The stator is basically a 3 coil winding and three phase AC power input is given to it. Principle of Operation. Thus the three phase induction motor is:Self-starting.Less armature reaction and brush sparking because of the absence of commutators and brushes that may cause sparks.Robust in construction.Economical.Easier to maintain. 1) 1. This rotor is a cylinder of steel laminations, with highly conductive metal (typically aluminum or copper) embedded into its surface. The rotating magnetic field induces current across the conductive bars, which further generates the rotors magnetic flux and causes the rotor to rotate. This rotating field produces an effect of rotating poles around a rotor. The squirrel cage induction motor is the most popular type of AC motor. Compared to squirrel cage rotor the rotor construction is not simple. 2.
The maintenance of this motor is more. Related Post: Cable Size Calculation for LT & HT Motors; Working Principle of Three-Phase Induction Motor The construction of Stator for any induction motor is almost the same.
This complete article is for you. Slip can be defined as the difference between the flux speed and the rotor speed. The upper slot conductors from the outer cage and the lower slot conductors form the inner cage. The resultant production of torque spins the rotor in the same direction as the rotation of the magnetic field produced by the stator. Answer (1 of 5): An induction motor is an electrical motor whic does not require external excitation of the rotor. of Poles P = 6, then Ns = 120 * 50/6: So Ns = 1000 r.p.m. Thats why its called squirrel cage induction motor. Induction motor works on the principle that whenever a closed conductor is placed in a magnetic field, it produces a torque or induction motor works on the combined effect of electromagnetic induction and motor principle. Hence, the rotor looks like a squirrel cage. 
Squirrel cage induction motor advantagesHigh efficiencySmall and lightweightDue to an absence of brushes, the chances of spark are reduced.These motors are provided with fans, so less heat is generated.Squirrel cage motors operate at nearly constant speed, high overload capacity, and operates at better power factor. Rayapureddi prasanth. This results in good operating efficiency and speed regulation. Reply.
The copper bars are shorted at the ends by circular end rings. Induction motor works on the principle of electromagnetic induction. The squirrel cage induction motor does not require a commutator, brushes, and slip rings. The Stator winding is assumed to be Y-connected with the access to the phase terminals. Its torque/speed and current/speed characteristics are such that, on starting, a torque of typically twice full-load torque is produced but a large current (typically, six to eight times full-load current) is drawn from the supply. 
In elaborating the working principle behind the Squirrel Cage Induction Motors, it utilizes the rotor bars in order to interact with electromagnetic force from the stators wherein the electromagnetic induction would be maximized to it full extent. Asynchronous Motors: Squirrel cage induction motor.
The stator usually contains windings of wire which carry an AC current; this current changes in sync with a sinusoidal curve which changes the current direction in 2) of Poles P = 4, then Ns = 120 * 50/4: So Ns = 1500 r.p.m. (Fig:2A). The rotor windings are placed in these rotor slots. This rotor setup looks like a squirrel cage at a closer look and hence it is called a squirrel cage Induction Motor. 2 shows the schematic representation of a three phase slip-ring induction motor. The stator winding can be either delta-connected or star-connected.The stator winding is connected to the three phase supply terminals. The advantages of squirrel-cage motors compared with the slip ring induction motors are given below. wound rotor induction motor) has the main benefit that it is easier to start than a squirrel cage motor. Depending upon the winding arrangement, the rotor of a 3-phase induction motor is of two types . Thus the speed control of squirrel cage induction motor can be done easily, but as steps of reduced speed.
Introduction A 3 phase squirrel cage induction motor is a type of three phase induction motor which functions based on the principle of electromagnetism.It is called a squirrel cage motor There are 2 main types of the motor first one is DC motors and the second one is AC motors. REFERENCES [1] Squirrel Cage Induction Motor: Working Principle and Applications. Various method have been developed for obtaining starting torque in these motors. Working Principle of Induction Motor. The torque of the induction motor depends on the rotor resistance. Working Principle, Induction motor is a machine that simply operates on the induction type principle. The star-delta starter is a very common type of starter and is extensively used for starting the squirrel cage induction motors. To make the step to the squirrel-cage induction motor, the squirrel cage rotor is equivalent to the ladder which is bent to a cylinder and the moving magnet is rep laced with the rotating magnetic field due to the three phase windings. The starting torque of this motor ranges from 200 to 250 percent of full-load torque with a starting current of 4 to 6 times the full-load value. The stator winding can be either delta-connected or star-connected.The stator winding is connected to the three phase supply terminals. Single Phase Induction Motor S Some of disadvantages or demerits of squirrel cage induction motors are listed below: Main disadvantage of squirrel cage induction motor is that they have poor starting torque and high starting currents. The Stator is the stationary part and the rotor is the rotating part. Stator: The stator is the outer most component in the motor which can be seen. Good speed regulation.
Thus under running condition, even the wound rotor is short circuited on itself just like squirrel cage rotor. Construction Of Squirrel Cage Induction Motor Any Induction Motor has a Stator and a Rotor. A hollow rotor would have a much less efficient performance. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable. This method is used for elevator motors, traction motors and also for machine tools.
Not like the single phase motor, a 3 phase motor power factor can reach up to 0.9. Where does the power go? But in induction motor, we give only one supply, so it is interesting to know how an induction motor works. Shaded pole motor is a split-phase type single phase induction motor.
Working of Squirrel Cage Induction motor. The induction motor is self-starting. Squirrel Cage Induction Motor Jazztine Andrei A. Gecolea School of Electrical, Electronics and Computer Engineering, Mapua University, Muralla St., Intramuros, Manila [email protected] I. Working Principle of AC Motors. Topics which are covered here: Slip ring induction motor application, construction, working principle, advantages and disadvantages, speed control of slip ring induction motor, the difference between Slip ring I.M and Squirrel cage I.M. A forerunner of the 3-phase induction motor was invented by Nikola Tesla sometime before 1889. Working Principle of Induction Motor We need to give double excitation to make a DC motor to rotate. The shaded pole motor is very popular for ratings below 0.05 HP (~ 40 W) because of its extremely simple construction. SQUIRREL-CAGE INDUCTION MACHINE Motor and generator principle of operations The rotating magnetizing field represented by the space vector Bm (or, equivalently by the magnetizing current Im) moves at the synchronous speed s with respect to a stator (or stationary) observer and at the slip speed sl = s - m with respect to a rotor observer. The construction of Stator for any induction motor is almost the same. This then creates a magnetic field which, through magnetic interaction, links to the rotating magnetic field in the stator which in turn causes the rotor to turn.
In the motor the slip rings, brushes are provided. A simple circuit diagram of the squirrel cage induction motor is shown in the figure. Starting torque will be in the order of 1.5 to 2 times the full load torque and starting current is as high as 5 to 9 times the full load current. No. The starting torque in a squirrel cage motor is small because of its low rotor resistance and there is no way to insert external The Star Delta starting method of squirrel cage induction motor lies on the concept of reduced voltage control. If you want to know about the slip ring induction motor. An . Slip is closely proportional to torque from zero to full load. This then creates a magnetic field which, through magnetic interaction, links to the rotating magnetic field in the stator which in turn causes the rotor to turn. The slip ring motor has very little application in industries. The reluctance motor has basically two main parts called stator and rotor. Construction Of Squirrel Cage Induction Motor Any Induction Motor has a Stator and a Rotor. Later, several experiments have been done to improve the performance of this type. The stator of the Induction motor is connected to the line power source that provides excitation. There will be a small gap between rotor and stator, known as air-gap. This paper proposes a new simplified model for small wind energy system consisting of: Induction generator, D-Statcom, excitation capacitors and loads. The rotor of a slip ring induction motor uses a distributed 3-phase winding. A squirrel cage induction motor will be composed of the squirrel cage windings.
1. Fig: 3.39 shows the operating characteristics of double squirrel-cage motor. When a three-phase AC supply is connected to the stator winding, it produces a rotating magnetic field in the air gap between the stator and rotor. Working principle of Squirrel cage induction motor Squirrel cage induction motor. 3-Phase Induction Motors EE 340 .
An induction motor (also known as an asynchronous motor) is a commonly used AC electric motor. As the name suggests, a three-phase squirrel cage induction motor contains a squirrel cage rotor (discussed above) and works on the three-phase AC supply. In the DC motor, we give one supply to the stator and another to the rotor through brush arrangement. This rotor is a cylinder of steel laminations, with highly conductive metal (typically aluminum or copper) embedded into its surface. It is called a squirrel cage motor because the rotor inside of it known as a squirrel cage rotor looks like a squirrel cage.
For understanding the working principle of an induction motor, let us consider a simple setup first as shown in the figure. Fig. When the switch S is in the START position, the stator windings are connected in star. So rotor starts rotating near synchronous speed as a squirrel cage induction motor. Hi friends, in this article, I am going to discuss about induction motor working principle and hoping you will like my effort. The speed of rotating magnetic field is synchronous speed, NS r.p.m. It is called a squirrel cage motor because the rotor inside of it known as a squirrel cage rotor looks like a squirrel cage. The most popular squirrel cage induction motor is of a 4-pole design. In an induction motor, to produce torque, at least some difference should be there in between stator field speed and rotor speed. 2: Schematic representation of a 3-phase slip-ring induction motor. A three-phase 1.5 hp squirrel motor is illustrated in Figure 3b. This motor should be mounted on the Motor Bench, wherein the motor shaft may be coupled to the Dynamometer for taking the measurements. If you want to add any further topic When the stator winding is supplied, the rotating magnetic field is set. If the shaft is forced to rotate at a speed higher than synchronous speed, the slip becomes negative and the induction generator starts delivering energy to the supply mains. By putting resistance in series with the rotor windings, the starting current can be kept low while maintaining good starting torque. The induction motor is also called asynchronous motor, it's a device for rotating a rotor by placing the rotor in a rotating magnetic field and thereof obtaining a rotating moment under the action of the rotating magnetic field. Such cylinder is shown in Figure 7. Fig. Read More If you want to add any further topic The Rotor sits inside the Stator. So, this motor only used when variable speed control and high starting torque are needed. But the rotor construction differs with respect to the type which is specified above. It is classed as a high-torque, low starting current motor. ; It is called a squirrel cage motor because the rotor inside of it known as a squirrel cage rotor looks like a squirrel cage. Squirrel cage Wound rotor (with slip rings) The rotating magnetic field principle-of-three-phase-induction-motor/ Per-phase equivalent circuit Motor Slip R 1 and R 2: stator and rotor winding resistances
i.e needs no starting capacitor like single phase induction motor. In order to reduce noise, the bars would be slanted in a small rotor. The resistance of the squirrel-cage rotor has an important effect on the operation of the motor. 3 Phase Induction Motor Advantages. It is used for starting a squirrel cage induction motor which is designed to run normally on delta connected stator winding. The picture of a tiny squirrel cage motor, illustrating the squirrel cage rotor, is shown in Figure 3a. (ii) Comparatively they have higher efficiency and power factor.
Disadvantages of No. It was invented by the scientist Tesla who earlier conducted several experiments on the working of the alternating current systems. In Squirrel cage induction motors the rotor is simplest and most rugged in construction. Here we will discuss construction and working principle of Reluctance Motor.
