Assume the as winding is sinusoidally distributed, with as and as. The induction motor stator resembles the stator of a revolving field, three phase alternator. At the end of the lecture, student should be able to. Causes and effects of single phasing induction motors article pdf available in ieee transactions on industry applications 416. Other possibilities include feeder or stepdown transformer fuses blowing. Three phase induction motor there are probably more single phase ac induction motors in use today than the total of all other types put together. The stampings are lotted on its periphery to carry the winding called stator winding or main winding. Perform an analysis on induction machines which is the most rugged and the most.
We need to give double excitation to make a dc motor to rotate. Three phase electric motors have many advantages over single phase electric motors. As the stator winding is fed from a single phase supply, the flux. The motor uses a squirrel cage rotor, which has a laminated. Speed of a dc shunt motor can be varied very easily with good efficiency, but in case of induction motors, speed reduction is accompanied by a corresponding loss of efficiency and poor power factor. Threephase induction motor, cage and wound slipring rotor, synchronous and rotor speed, slip, induced voltages in stator winding and rotor bar.
They are found everywhere from a small workshop to a large manufacturing industry. In this module we will be discussing the three phase induction machine. The rotor will constantly be turning to align its magnetic field with that of the stator field. How does a singlephase induction motor capacitor induction motor or ac motor work. Refer back to this diagram as the operational requirements of the single phase motor are discussed. Single phase induction motor constructional featuresdouble revolving field theory equivalent circuit split phase motors capacitor start capacitor run motors. The construction of the circle diagram is based on the approximate equivalent circuit shown below. The maximum amount of power is transferred through three phases as compared to single phase supply. The slots are provided on its stamping to carry stator or main winding. Pdf causes and effects of singlephasing induction motors. They run at essentially constant speed from zero to fullload. Single phase induction motor, theory of operation double revolving field theory, equivalent circuit, determination of parameters methods of starting, split phase starting, repulsion starting, shaded pole starting, performance characteristics. Double field revolving theory ac current flows through the stator two fields are generated 1f forward rotating field 2bbackward rotating field pulsating field due to various magnitudes of field at diff time 2 3.
Oct 04, 2017 speed torque characteristics of induction motor from eq. Instead of a rotating magnetic field, it produces a magnetic field which pulsates due to ac oscillations between 0 and 180 degrees. Induction motor 1 chapter 3 induction motor bee23 electrical machine power system 2 learning outcomes. The single phase motor stator has a laminated iron core with. When the rotor resistance is increased, so is the slip for maximum torque, and the stable operating slip range of the. Rotating and pulsating field, development of equivalent circuit based on double revolving field theory, torqueslip. A single phase induction motor is very similar to a 3 phase squirrel cage induction motor. One single phase wattmeter plus miscellaneous apparatus as needed.
Brushless dc motors nyu tandon school of engineering. This singlephase motors are truly two phase machines. Assume that the current flowing in the as winding is a constant. Single phase motors are very widely used in home, offices, workshops etc. The single phase ac induction motor bests fit this description. The staring torque of induction motor is very high which makes motor useful for operations where load is applied before the starting of the motor. Craig 22 singlephase devices consider the device shown which illustrates a singlephase stator winding. These are of two types, squirrel cage and slip ring motors. It is logical that the least expensive, lowest maintenance type motor should be used more often. 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. Torque speed characteristics of induction motor slip power. Circuit diagram for noload and blockedrotor test on 3 phase induction motor a. The 3 phase set of currents, each of equal magnitude and with a phase.
A single phase induction motor is an electric motor that operates on a single waveform of alternating current. The constructional details of single phase induction motor are shown in figure. The single phase motor stator has a laminated iron core with two windings arranged perpendicularly. Hi all, so im working on a project titled controlling the speed of a single phase induction motor. Single phase motors have only two power source supply lines connected. For the proper working condition, three phases of the induction motor are better than the single phase of the induction motor. A diagram of a simple shaded pole motor is shown in fig. Typically these motors are used in small sizes, and the most familiar application may be a bathroom fan. Single phase motors will last for years as well, and usually, most failures from single phase motors are a result of an inappropriate. Induction motor is an ac electric motor, having a stator and a rotor just like other motors, but the working principle is a little different which would be discussed further. 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.
In this study, a three phase induction motor drive using fieldoriented vector controlled algorithm was designed and implemented. Single phasing can occur as a result of a fuse blowing or a protective device opening on one phase of the motor. The rotor is of squirrel cage type, which is a cheap one, as the rating of this type of motor is low, unlike that for a three phase im. Single phase induction motor, theory of operation double revolving field theory. 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. Since a commutator motor can operate at a much higher speed than an induction motor, it can output more power than a similar size induction motor. Record all nameplate information for the induction motor. Disconnect any mechanical load connected to the induction motor. Working of single phase induction motors is explained in this video with help of animation. This paper presents design and analysis of a three phase induction motor drive using igbt. The motor then produces a constant torque and not a pulsating torque as in other singlephase motors. Three phase motor the three phase induction motors are the motors mostly frequently encountered in industry.
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. The singlephase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Circle diagram of an induction motor its construction. Circle diagram of an induction motor the circle diagram of an induction motor is very useful to study its performance under all operating conditions. As mentioned above that, due to the rotating magnetic field of the stator, the induction motor becomes self starting. Thus, as an electrical and electronics engineer or hobbyist we must know a few basic concepts about these types of machines we use regularly in our life. Design of single phase induction motor linkedin slideshare. In developed countries today there are more than 3 kw of electric motors per person, today and most of it is from induction motors. It supplies an induction motor ich has a full load speed of 144wh 0 rpm. The single phase induction motor is much the same in construction as the three phase motor. It presents a design of a lowcost, highefficiency drive capable of supplying a single phase a.
Noload and blocked rotor test on an induction machine aim theory. While researching on the internet i came across this one circuit that proposes a model that uses a microcontroller and a triac circuit and a. For the latter two technologies, we consider the case of three phase power, which is generally preferred over single phase because of much higher power density. Both types are popular but for larger sizes the induction motor is the most highly. Nptel syllabus electrical machines i video course course outline. Dec 19, 2015 types of single phase induction motors.
This is the basic principle followed by all these types of single phase induction motors. It is a 16 bit highperformance digital signal controller dsc. The motor uses a squirrel cage rotor, which has a laminated iron core with slots. Single phase induction motors questions and answers. How does a single phase induction motor capacitor induction motor or ac motor work. Single phase series motor, theory of operation performance and application, shcrage motor. Speed control of single phase induction motor by using. Especially, the domestic application like the electric motors works on the three phase system. 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. There are a multitude of singlephase motor combinations. Applications of single phase induction motor pnpntransistor. The motor then runs as a singlephase induction motor.
A single phase induction motor is inherently not selfstaring can be shown easily. Oct 05, 2016 a single phase induction motor differs in operation from a 3 phase induction motor in the sense that this motor cannot generate a rotating magnetic field. The rotor is a rotating part of an induction motor. The single phase induction motor is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Introduction to induction motor the engineering projects. The rotor of an induction motor can be a squirrel cage rotor or wound. Find the percentage slip and number of poles of the induction motor.
Single phase induction motor split phase, capacitor and shaded pole etc. Drm039, single phase ac induction motor control reference. A single phase induction motor is very similar to a 3phase squirrel cage induction motor. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. Types of single phase induction motors single phase. The single phase ac version suffers a double line frequency torque pulsation, not present in the polyphase motor. They run at a constant speed from noload to the full load. Single phase induction motors have non zero running torque. There are two types of induction motors, one is named as single phase induction motor, while the second one is named as 3 phase induction motor.
The device is aimed at substituting the commonly used triac phase angle control drives. In addition to this, single phase motors are reliable, cheap in cost, simple in construction and easy to repair. However, the slip at which the maximum torque occurs changes with rotor resistance. There are three types of single phase induction motors which are the shaded pole, split phased, and capacitor. Jul 11, 2019 as its name indicates stator is a stationary part of induction motor. Singlephase motor starting in addition to the run or main winding, all induction singlephase motors are equipped with an. This strange behavior of single phase induction motor can be explained on the basis of doublefield revolving theory. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm.
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. Dc motor, the ac induction motor, and the ac synchronous motor. So, this document provides information about single phase induction motor, constructionstator, rotor, working principle, types of single phase induction motors, starting methods of single phase induction motors, and applications of single. Singlephase induction motors are used in residential applications for ac motor appliances in single, or multiple dwellings.
Excitation and power circles hunting and its suppression methods of starting synchronous induction motor. The advantages of threephase ac induction motor are listed below. Causes and effects of singlephasing induction motors. Speed control of single phase induction motor by using triac x4e67o08w8n3. Equivalent circuit of a single phase induction motor the equivalent circuit of a single phase induction motor can be obtained by two methods named as the double revolving field theory and cross field theory. Stampings are made up of silicon steel to reduce the hysteresis losses.
Note down the machine ratings and calculate rated current of the machine noload test. Shaded pole motor is a split phase type single phase induction motor. Induction motor basics, single phase and three phase. The most common type of ac motor being used throughout the work today is the induction motor. There are many methods of making a single phase induction motor as self starting one. Based on the starting method, single phase induction motors are basically classified into the. The singlephase stator winding produces a magnetic field that pulsates in strength in a sinusoidal manner.
Ac commutator motors ac motors electronics textbook. Jan 11, 2018 synchronous speed, frequency, and poles of the induction motor are related by the formula. Three phase ac induction motors are widely used in industrial and commercial applications. Single phase induction motor the winding used normally in the stator fig. However, single phase induction motors does not have self starting torque and are made to. Various starting methods used in the singlephase induction motors, with the intro duction of additional features, like the addition of another winding in the stator. However, the constraint in selecting the use of three phase electric motor is the availability of three phase electric service where you need it. Single phase induction motors are the simple motors which operate on single phase a. Rotating and pulsating field, development of equivalent circuit based on double revolving field theory, torqueslip characteristic. The single phase motor can operate off either the ab, bc, ca, an, bn, or cn power source. How a single phase motor is similar to 3 phase motor.
It is well known that a three phase induction motor will continue to operate when a disturbance of some sort causes the voltages supplied to the motor to become single phased. What are the advantages of a 3phase induction motor over. 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. The motor is mounted in a test rig that allows one to control the torque. Understand the principle and the nature of single phase and 3 phase induction machines. The circuit operation is controlled by a tiny mc68hc908qt4 mcu. Aluminum bars are molded on the slots and shortcircuited at both ends with a ring. Starting methods for singlephase induction motor nptel. Cogging crawling effect in a 3 phase induction motor.
Nov 03, 2019 an induction motor also known as an asynchronous motor is a commonly used ac electric motor. Sensorless speed control was achieved via vector control. These motors are selfstarting and use no capacitor, start winding, centrifugal switch or other starting device. Single phase machines are restricted to small power levels. Umanand, principal research scientist, power electronics group, cedt, iisc bangalore for more details on nptel visit. Single phase induction motors arenot a selfstarting motor, and three phase induction motor are a selfstarting motor. Types of single phase induction motors electronics hub. The shaded pole motor is very popular for ratings below 0.
Electrical machines i video course electrical engineering nptel. Once the motor picks up the speed, this additional winding is removed from the supply. It has i a squirrelcage rotor identical to a 3 phase motor ii a single phase winding on the stator. Find the synchronous speed of 4 pole induction motor which operates at 60 hz. Applications of three phase induction motors of size varying from half a kilowatt to thousands of kilowatts are numerous.
An induction motor is practically a constant speed motor, that means, for the entire loading range, change in speed of the motor is quite small. Gradually apply three phase voltage across motor stator terminals via the autotransformer d. One class of single phase induction motor that is cheaper than any of the two winding or split phase designs is the shaded pole motor. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. Single phase induction motor the engineering projects. The stator of a single phase induction motor is wound with single phase winding.
Unlike a 3phase induction motor, a singlephase induction motor is not self starting but requires some starting means. Pdf speed control of induction motor using pi and vf. When a 1 phase supply is connected to the stator winding, a pulsating magnetic field is produced. It has distributed stator winding and a squirrel cage rotor. What is major difference between a 3 phase induction motor and a single phase induction motor. Two rotating field theory, toquespeed characteristics. Jan 02, 2017 singlephase induction motor this singlephase motors are truly two phase machines.
It is the diagrammatic representation of the performance of the induction motor. Induction motors are rugged and have moderate costs, explaining their popularity. The rotor in the single phase induction motor is of squirrel cage rotor type. The singlephase motor stator has a laminated iron core with two windings arranged perpendicularly. A single phase induction motor consists of a single phase winding on the stator and a cage winding on the rotor. The rotor connects the mechanical load through the shaft. Testing and performance of single phase transformers. Speed control of single phase induction motor using triac. Equivalent circuit of a single phase induction motor. Stator of single phase induction motor the single phase motor stator has a. The three phase induction motor is the extensively used for various kinds of industrial drives. Ac commutator motors may be either single phase or poly phase. Single phase induction motors multiple choice questions.
The main winding of a single phase induction motor produces a magnetic field. The stator has laminated construction, made up of stampings. Single phase induction motors are of different types based on their starting conditions and various factors. While most induction motors are still fed from three phase or single phase. Induction type energy meter used invariably to measure the energy consumed in any a.
A brief on single phase induction motor pdf elprocus. Shaded pole induction motors working and construction. Firstly the equivalent circuit is developed on the basis of double revolving field theory when only its main winding is energized. Some single phase induction motors are also called squirrel cage motors because of the rotors similarity. The stator of the singlephase induction motor has laminated stamping to reduce eddy current losses on its periphery. Unless otherwise specified, the auxiliary circuit is assumed to be opened when the motor has attained a predetermined speed. The speed is frequencydependent and, consequently, these motors are not easily adapted to speed control. Chapter 3 induction motor and different speed control methods page no 3. When the stator is fed with a single phase supply, it produces alternating flux which alternates along one space axis only. Working principle of a single phase induction motor. This is one of the most widely used types of single phase induction motors.
The stator or the stationary part consists of three phase winding held in place in the slots of a laminated steel core which is enclosed and supported by a cast iron or a steel frame as shown in fig. Ac induction motors are also the most common motors used in main powered home appliances. The stationary part in single phase induction motors is stator and the rotating part is rotor. Tech in electrical engineering iase deemed university. Pdf lecture 1 single phase induction motor sri vidhya.