There are two types of induction motors, one with wound type rotor, also called slipring motor and another one with squirrelcage rotor. Dec, 2018 electrical engineering three phase induction motor objective types question and answer in hindi in this video we know about 25 important 25 objective questions with their answer in hindi which. The single phase induction motor is much the same in construction as the three phase motor. The three phase induction motors are simple in construction, rugged, low cost and easy to.
For this motors, we require three phase power supply, whereas thus three phase power must be supplied in. The frame of three phase induction motor should be strong and rigid as the air gap length of three phase induction motor is very small. This final thesis will mostly be dedicated to induction motors but also to synchronous permanent magnet and reluctance motors. Different types of fault in three phase induction motor. Nov 03, 2019 there are basically two types of induction motor. Consider the working of a motor for a better understanding of these indicators. A 3 phase induction motor can be used for different applications with various speed and load requirements. This induces an electric field in a coil or squirrel cage to drive a rotor.
Understanding motor nameplate information nema vs iec. Some single phase induction motors are also called squirrel cage motors because of the rotors similarity to a circular animal exercise wheel. Since the rotor is of squirrel cage type, there is no rotor insulation and hence the rotor structure is more robust. An induction motor can therefore be made without electrical connections to the rotor. Thus the rotor rotates in the same direction as that of stator flux to minimize the relative velocity. One single phase wattmeter plus miscellaneous apparatus as needed. Three phase induction motor for industrial general purpose toshiba. The threephase induction motor is the extensively used for various kinds of industrial drives. Induction motor basics, single phase and three phase. Types of single phase induction motors electronics hub. This elearning module provides a basic understanding of three phase induction motors. Ac induction motors are also the most common motors used in main. Compare the rotation of this motor with that in figure 164. Squirrel cage induction motor and slip ring or wound rotor induction motor.
The types of induction motor depend upon the input supply. This article concentrates only on three phase induction motor and its protection. Unit 16 electric motors washington state university. An induction motor can be, squirrel cage induction motor. The stator of the threephase induction motor consists of three main parts. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. The magnet is spun by a 3 phase ac motor with no rotor voltage 4. Different types of electric motors and their applications. Rotating flux is only possible when 3 phase voltage or poly phase which is 120 degree apart in time is applied to a three phase winding or poly phase winding 120 degree apart in space then a three phase rotating magnetic flux is. Induction motor basics, single phase and three phase induction. Squirrel cage wound rotor with slip rings the rotating magnetic field. The vertical mounting type motors should be transported in the vertical position.
When the 3 phase stator windings are fed by 3 phase supply, a magnetic flux of constant magnitude which is rotating at synchronous speed is set up. An ac motor is an electric motor driven by an alternating current ac. 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. 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. Understanding motor nameplate information nema vs iec standards. There are two different types of the structure and similar in electrical properties. Introduction this application note describes the design of a 3phase ac induction motor drive with volts per hertz control in closedloop vhz cl. Home category electrical engineering mcq questions and answers 3 phase induction motors. This is the basic working principle of induction motor of either type, single phase of 3 phase. Induction motor 1 chapter 3 induction motor bee23 electrical machine power system 2 learning outcomes. The frame is either made up of diecast or fabricated steel.
Types of electric motors electric motors dc motors other motors h ac motors s unt motor separately excited. Applications of single phase induction motor pnpntransistor. Threephase ac induction motors are widely used in industrial and commercial applications. Introduction types of electrical machines types of 3 ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. Designation explanation of induction motor type 160 m operating conditions 1 3. A 3 phase induction motor has two main parts i stator and ii rotor. Threephase induction motor protection systems and its. The singlephase induction motor is much the same in construction as the threephase motor. But at the starting of the induction motor, starting current is very large which may damage motor windings. Construction of three phase induction motor electrical4u. The induction motor stator resembles the stator of a revolving field, three phase alternator. These are of two types, squirrel cage and slip ring motors.
Hello everyone, i am niko and, in this instructables i will show you, how to rewind and renew old three phase electric motor. If you are searching for rewinding of one phase motor you can find it here. Dec 19, 2015 single phase induction motors are used primarily for domestic and lightindustrial applications where three phase supply is generally not available. The threephase motor design was also worked on by the swiss engineer charles. Jan 02, 2020 polyphase induction motor mcq with explanation in case of 3 phase induction motors the ratio of core length to pole pitch for minimum cost is taken as. An electrical motor is an electromechanical device which converts electrical energy into mechanical energy. The 3phase set of currents, each of equal magnitude and with a phase. Single phase induction motors are used extensively for smaller loads, such as household appliances like fans. Induction motors are generally two types as we see in the previous article. The construction of stator for both the kind of three.
Mostafa elshahed objectives learn a brief history of the electrical power systems construction. Flexible 5 ratings correspondence 220380415v50hz,220440v60hz is standard. The single phase induction motor is not selfstarting. It is the outer part of the three phase induction motor. Induction motor totallyenclosed fancooled nema standard epact three phase induction motors sdesign versatility teco totally enclosed fan cooled squirrelcage induction motors are designed, manufactured and tested to meet or exceed the latest nema, ieee, csa and. The rotor is separated from the stator by a small airgap which ranges from 0. For reason of economy, most houses, offices and also rural areas are supplied with single phase a.
Determination of the losses in induction machines due to harmonics pdf. The two main types of ac motors are induction motors and synchronous motors. There are three types of capacitor motors, as follows. An electrical motor is a device that has brought about one of the biggest advancements in the fields of engineering and technology ever since the invention. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. The single phase induction motor resembles, three phase, squirrelcage motor except that, single phase induction motor has no starting torque and some special arrangement have to be made to make it as self starting. When the 3 phase supply is provided to the stator, a magnetic field is produced which rotates the rotor and motor starts. Three phase squirrelcage induction motors are widely used as industrial drives because they are selfstarting, reliable and economical.
Uses soft magnet rotor that is magnetized by the application of current in the stator coils 3. They run at a constant speed from noload to the full load. Three phase induction motor faults and their causes. As discussed in chapter 16, the squirrel cage comprises the bars and.
Unit 16 electric motors objectives after studying this unit, the student will be able to state the purpose of an electric motor. Explain starting methods of 3 phase induction motor. Electrical engineering three phase induction motor objective. The types of single phase induction motors include. Phase wound induction motor slipring induction motor. Methods of starting three phase induction motors as we know, once a supply is connected to a three phase induction motor a rotating magnetic field will be set up in the stator, this will link and cut the rotor bars which in turn will induce rotor. There are two basic reasons for the use of single phase motors rather than 3 phase motors. Single phase induction motors are used primarily for domestic and lightindustrial applications where three phase supply is generally not available. Ac induction motors are also the most common motors used in main powered home appliances. A single phase induction motor is inherently not selfstaring can be shown easily.
Single phase induction motors arenot a selfstarting motor, and three phase induction motor are a selfstarting motor. When the motor is connected to a single phase power supply, the main winding carries an alternating current. Squirrel cage induction motors a stator construction. There are single phase induction motors and three phase induction motors. As mentioned above that, due to the rotating magnetic field of the stator, the induction motor becomes self starting. Like any electric motor, a 3 phase induction motor has a stator and a rotor. Please refer to this link to know more about induction motor types and advantages. For three phase induction motors frames 143t 449t 18060 109 ave edmonton, ab t5s 2k2. The rotor composes of concentric strips of magnetic iron isolated from each other. You should also make a dc measurement of stator winding linetoline resistance.
Refer back to this diagram as the operational requirements of the singlephase motor are discussed. The difference in speed between rotor, the synchronous speed and the rotating. Differentiate between the various types of generating electric power stations. Types of single phase induction motors as mentioned above that, due to the rotating magnetic field of the stator, the induction motor. Understand the principle and the nature of single phase and 3 phase induction machines. Frame size 180m and above, 380660v50hz is standard. Star delta starter for 3phase motor electronics hub. Starting method for induction motors a 3 phase induction motor is theoretically self starting. An induction motors rotor can be either wound type or squirrel cage type.
A 3 phase induction motor uses current delivered in three phases in a sequence into the coils of a stator to create a rotating magnetic field. Both types have similar constructed rotor, but they differ in construction of rotor. The basic idea of an electric motor is to generate two magnetic fields. Three phase induction motors are constructed into two major types. The rotor will constantly be turning to align its magnetic field with that of the stator field. The induction motor is started by itself that we know.
The stator of an induction motor consists of 3 phase windings, which when connected to a 3 phase supply creates a rotating magnetic field. The types of induction motors can be classified depending on whether they are a single phase or three phase induction motor. Slip ring induction motor or wound rotor induction motor or phase wound induction motor. The stator carries a 3 phase winding called stator winding while the rotor carries a shortcircuited winding called rotor winding only the stator winding is fed from the 3 phase supply. Three phase or poly phase motors are of mainly two types. 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. Motor starters are types switches either electromechanical or solid state that are designed to start and stop the motors by providing the necessary power to the motor and preventing the. Applications of three phase induction motors of size varying from half a kilowatt to thousands of kilowatts are numerous. Perform an analysis on induction machines which is the most rugged and the most. This strange behavior of single phase induction motor can be explained on the basis of doublefield revolving theory. There are two types of 3 phase induction motors based on the type of construction of rotor. At the end of the lecture, student should be able to. Types and construction of three phase induction motor.
However, the rotor never succeeds in catching up the synchronous speed. An induction motors rotor can be either wound type or squirrelcage type. The most common type of ac motor being used throughout the work today is the induction motor. The frame of an induction motor is usually made of. Record all nameplate information for the induction motor. Generally 3 phase induction motors have a high starting torque, high power factor, high efficiency, and low current.
Does not use a switch, capacitor or relay for starting. It is based on freescales 56f800e microcontrollers. In this chapter, we shall focus our attention on the construction. The first ac commutatorfree threephase induction motors were. The principle of rotating type phase sequence indicator is like that phase motor. Generally, two types of induction motors are used in our industry such as wound rotor and squirrel cage rotor, but their faults are almost same. Its main function is to support the stator core and the field winding. The 3 phase induction motor is usually called according to the type of its rotor to distinguish between the two types wound rotor type. It acts as a covering and provides protection and mechanical strength to all the inner parts of the machine. Single phase motors will last for years as well, and usually, most failures from single phase motors are a result of an inappropriate application rather. Difference is that transformer is an alternating flux machine while induction motor is rotating flux machine.
By far the most commonly used ac motor is the induction motor. Synchronous motors are special types of motors used in constant speed applications, whereas most of the motors used in the industrial applications are of induction type. Just like any other motor, a 3 phase induction motor also consists of a stator and a rotor. Different types of motors used in electric vehicles. An induction motor or asynchronous motor is an ac electric motor in which the electric current. Figure 1 three phase induction motor with all their essential parts. A capacitor motor is a single phase induction motor with a main winding arranged for a direct connection to a source of power and an auxiliary winding connected in series with a capacitor. Phase induction motors capacitorstart induction motor dynamic and steadystate performance of a capacitorstart singlephase induction. These types of motors are known as selfstarting induction motors.
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