The rotor is a rotating part of an induction motor. Working principle of a single phase induction motor circuit globe. Although single phase induction motor is more simple in construction and is cheaper than a 3phase induction motor of the same frame size, it is less efficient and it operates at lower power factor. In addition to this, single phase motors are reliable, cheap in cost, simple in construction and easy to repair. Slip ring induction motor is made up from wound rotor and squirrel cage induction motor is made up from the squirrel cage rotor. A single phase induction motor construction is similar to a 3phase squirrel cage induction motor consists of singlephase winding on the stator and a squirrel. Construction of single phase induction motor youtube. The construction of these motors is more or less similar to a threephase squirrelcage induction motor. Both types are popular but for larger sizes the induction motor is the most highly. In twopole singlephase motors, the torque goes to zero at 100% slip zero speed, so these require alterations to the stator such as shadedpoles to provide starting torque. The single phase motor stator has a laminated iron. So, first of all have a look at the functionality of stator of single phase induction motor. A single phase induction motor works on single phase supply while 3 phase on 3.
In a split phase motor, the running winding should have a high resistance and low inductance b low resistance and high inductance c high resistance as well as high inductance d low resistance as well as low inductiance ans. It has salient poles on the stator excited by a singlephase supply and a squirrel cage rotor. The capacitor start single phase induction motor is a type of splitphase induction motor. Working principle of a single phase induction motor with electrical machine, single phase transformer, construction of single phase transformer, losses in transformer, opencircuit and shortcircuit test, threephase transformer, auto transformer etc.
What is the difference between 1phase and 3phase induction. The stator winding carries an alternating current which produces the flux which is also alternating in nature. 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. There are three basic types of small induction motors. In an induction motor, the rotor rotates because of slip i. The rotor is cylindrical and has slots all over its periphery. Nov 03, 2019 an induction motor also known as an asynchronous motor is a commonly used ac electric motor. The slots are not made parallel to each other but are a little bit skewed as the skewing prevents magnetic locking of stator and rotor teeth and makes the. The stator is the fixed part of the motor to which a. Between the mains supply terminals and motor terminals the dol starter main terminals are connected and with the two terminals of the threephase power supply as described in figure 1 the control circuit is energized.
The rotor is separated from the stator by a small airgap which ranges from 0. We will have a look at both stator and rotor one by one below. Capacitors are used to improve the starting and running performance of the singlephase inductions motors. The capacitor start single phase induction motor is a type of split phase induction motor. Single phase motors are simple in construction, reliable and economical as compared to three phase induction motors. Single phase induction motors spim arent self starting. 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. One is the main winding and the other is the auxiliary winding. When the motor is connected to a singlephase power. The laminations are insulated from each other usually by a varnish layer.
It may be constructed for single phase, three phase or even poly. Some single phase induction motors are also called squirrel cage motors because of the rotors similarity to a circular animal exercise wheel. Some singlephase induction motors are also called squirrel cage motors because of the rotors similarity. The single phase motor stator has a laminated iron core with two windings arranged perpendicularly. Ac commutator motors ac motors electronics textbook. Squirrel cage and wound rotor or slip rig induction motor. The construction of single phase induction motor is almost similar to the squirrel cage three phase motor except that in case of asynchronous motor the stator. Single phase induction motor double revolving field theory the threephase induction motor starting torque inversely depends on the slip this implies that a small positive slip 0. The construction parts on of single phase induction motor consist of main two parts. As the winding resistance of starting winding is high, the angle between voltage and current i s is small similarly the inductance of the running or main winding is high therefore the angle between i m and v is very large but less than 90 0 the starting torque in the split phase motor is directly proportional. Sep 12, 2018 in this video i have explained about single phase induction motor. I have explained its construction in my article on 3 phase induction motor. Based on the rotor construction, 3 phase induction motor can be of two types.
The stator frame consists of laminations of silicon steel, usually with a thickness of about 0. But the rotor construction differs with respect to the type of motor. Construction of single phase induction motor electrical. Capacitor start single phase induction motor working and. Construction of squirrel cage induction motor explained. An887, ac induction motor fundamentals microchip technology. Induction generators are also called as asynchronous generators. Three phase squirrelcage induction motors are widely used as industrial drives because they are selfstarting, reliable and economical. Single phase motors are simple in construction, reliable, easy to repair and comparatively cheaper in cost and therefore, find wide use in fans, refrigerators, vacuum cleaners, washing machines, other kitchen equipment, tools, blowers, centrifugal pumps, small. A single phase induction motor is inherently not selfstaring can be shown easily. The starting torque of single phase induction motor is low, whereas the starting torque of three phase induction motor is high.
A single phase induction motor requires separate starting circuitry to provide a rotating field to. Why there is no starting torque in a singlephase induction motor with one main. Working principle of a single phase induction motor with electrical machine, single phase transformer, construction of single phase transformer, losses in transformer, opencircuit and shortcircuit test, three phase transformer, auto transformer etc. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy to mechanical energy, and vice versa. Electric motor electric motor construction of induction motors. There are mainly two types of induction motor on the basis of power supply, single phase induction motor and three phase induction motor. The torque in a hysteresis motor is produced due to hysteresis and eddy current induced in the rotor by the action of the rotating flux of the stator windings. A resistance start motor is a splitphase induction motor with a starter inserted in series with. The stator is a stationary part and it has laminated construction, which is made up of stampings. The singlephase induction motor is much the same in construction as the threephase motor. Single phase motors are easy to repair and maintain, but the maintenance of three phase motors difficult. The construction of these motors is more or less similar to a three phase squirrelcage induction motor. Capacitors are used to improve the starting and running performance of the single phase inductions motors.
The single phase induction motor is much the same in construction as the three phase motor. Electric motor construction of induction motors britannica. The rotor will constantly be turning to align its magnetic field with that of the stator field. List and describe the more commonly used equipment in an electric substation. The main characteristic of this kind of motor is the same as that of a threephase.
A rotor and a stator are the two main components of single phase induction motor. These stampings consists of slots on its periphery to carry the. The stationary part in singlephase induction motors is stator and the rotating part is rotor. The 3phase set of currents, each of equal magnitude and with a phase. Jul 11, 2019 the construction of the rotor of the single phase induction motor is similar to the squirrel cage three phase induction motor. Refer back to this diagram as the operational requirements of the singlephase motor are discussed. Difference between single phase and three phase induction. A hysteresis motor is a synchronous motor with a uniform air gap and without dc excitation. Singlephase induction motors ac motors electronics textbook.
The capacitor start motor is identical to a split phase motor except that the starting winding has as many turns as the main winding. Working principle of single phase induction motor and its. But the rotor construction differs with respect to the type which is specified above. Before starting to explain how an induction asynchronous generator works, i assume that you know the working principle of an induction motor. An induction motor is the most modest electrical machine from constructional point of view, in the majority of the cases. One is almost identical to that of the threephase induction motor while the other is of a form similar to that of the d. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy. Lamination is necessary since a voltage is induced along the axial length of the steel as well as in the stator conductors. Single phase induction motors multiple choice questions. The construction of single phase induction motor is almost similar to the squirrel cage threephase induction motor. Rotor has slots on all over its surface to carry conductors that are copper or aluminum bars.
It is widely used when compared to the three phase motor for the industrial, commercial and domestic purposes. The rotor of an induction motor can be a squirrel cage rotor or wound. The capacitor start motor is identical to a splitphase motor except that the starting winding has as many turns as the main winding. A starting mechanism like resistor or capacitior split phase is required. You should also make a dc measurement of stator winding linetoline resistance using a dmm. The single phase motor stator has a laminated iron core with. The main parts of a single phase induction motor are the stator, rotor, windings. Mostafa elshahed objectives learn a brief history of the electrical power systems construction. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. The construction of singlephase induction motors is shown in below figure. The vector diagram for the split phase induction motor is shown in the figure b. A 3 phase induction motor has two main parts i stator and ii rotor.
A capacitor start motor is a splitphase induction motor with a starting capacitor inserted in series with the startup winding, creating an lc circuit which produces a greater phase shift and so, a much greater starting torque than both splitphase and shaded pole motors resistance start motor. Working principle of a single phase induction motor javatpoint. Similarly the inductance of the running or main winding is high therefore the angle between i m and v is very large but less than 90 0. The construction of the rotor of the singlephase induction motor is similar to the squirrel cage threephase induction motor. The rotor in the singlephase induction motor is of squirrel cage rotor type. The stator is the outer most component in the motor which can be seen. One singlephase wattmeter plus miscellaneous apparatus as needed. Induction motor works on the principle of induction where electromagnetic field is induced into the rotor when rotating magnetic field of stator cuts the. Shaded pole motor is a splitphase type single phase induction motor. The basic construction of single phase induction motor is similar to all other motors. Single phase induction motor double revolving field theory the three phase induction motor starting torque inversely depends on the slip this implies that a small positive slip 0. Hysteresis motor a hysteresis motor is a synchronous motor with a uniform air gap and without dc excitation. The significant difference is, of course, that there is only a single phase supply to the stator. Shaded pole motor is a split phase type single phase induction motor.
Although single phase induction motor is more simple in construction and is cheaper than a 3 phase induction motor of the same frame size, it is less efficient and it operates at lower power factor. One is almost identical to that of the three phase induction motor while the other is of a form similar to that of the d. The page includes the construction, working principle of single phase induction motor. Single phase induction motor the engineering projects. Various starting methods used in the singlephase induction motors, with the intro. The rotor connects the mechanical load through the shaft. Single phase induction motor split phase, capacitor and shaded pole etc. As the winding resistance of starting winding is high, the angle between voltage and current i s is small. The stator has laminated construction, made up of stampings. The significant difference is, ofcourse, that there is only a single phase supply to the stator. This motor starts automatically self but a 1phase induction motor will not start automatically because it cannot expand starting torque. The brushes may also be lifted to prolong brush life. 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. Feb 14, 2016 construction of single phase induction motor watch this video to learn the construction of single phase induction motor to learn more register at.
The working principle and construction of capacitor start inductor motors and capacitor start capacitor run induction motors are almost the same. This flux links with the rotor conductors and due to transformer action e. Working principle of a single phase induction motor. A threephase motor may be run from a singlephase power source.
The operation of the singlephase induction motor can be done through a single power phase and used in domestic as well as industries. Construction of single phase induction motor watch this video to learn the construction of single phase induction motor to learn more register at. The shaded pole motor is very popular for ratings below 0. The motor is mounted in a test rig that allows one to control the torque. Starting methods for singlephase induction motor nptel.
Construction of single phase induction motor for general lighting purpose in shops, offices, houses, schools etc. Single phase induction motor 1introduction the singlephase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Single phase induction motor split phase, capacitor and. Just like a dc machine, a same induction machine can be used as an induction motor as well as an induction generator, without any internal modifications. In this video i have explained about single phase induction motor. Its very simple and interesting, but its not all we will get more by knowing the types of a single phase induction motor, their usage, and importance. The construction of stator of the induction motor is almost the same as other motors. The singlephase motor stator has a laminated iron core with. The basic idea of an electric motor is to generate two magnetic fields. Oct 05, 2016 rotor of a single phase induction motor is similar in construction with a squirrel cage 3 phase induction motor. Single phase induction motors the single phase induction motor comes with the different starting arrangements.
Generally, there are two types of the induction motors known as single phase and three phase induction motors. Single phase induction motor working, construction. Induction motor seminar ppt, pdf report study mafia. The singlephase series motor is an attempt to build a motor like a dc commutator motor.
An induction motor s rotor can be either wound type or squirrelcage type. Dec 19, 2015 single phase induction motors consist of two main parts. Single phase induction motors consist of two main parts. Some singlephase induction motors are also called squirrel cage motors because of the rotors similarity to a circular animal exercise wheel. A motor with only armortisseur windings is called an induction motor. Shaded pole induction motors working and construction. Single phase induction motor the single phase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Pdf on may 3, 2019, ahmed m t ibraheem alnaib and others. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. Single phase motors are very widely used in home, offices, workshops etc. Induction motor basics, single phase and three phase.
The resulting motor is only practical in the smallest sizes. The construction of stator for any induction motor is almost the same. As discussed in chapter 16, the squirrel cage comprises the bars and. Starting torque is 300% to 600% of the full speed value as compared to under 200% for a pure induction motor. The rotor of an induction motor can be a squirrel cage rotor or wound type rotor.
Record all nameplate information for the induction motor. They run at a constant speed from noload to the full load. Difference between single phase and three phase induction motor. Single phase induction motor 1introduction the single phase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Types of single phase induction motors electronics hub. Most of the application of industrial as well as domestic are this type of induction motor. Differentiate between the various types of generating electric power stations. The construction parts on of single phase induction motor consist of main two.