Similarly, example 2 is a 3 phase, 6 pole, 50 hertz induction motor has. Lecture 6 three phase induction motors cairo university. Starting of 3 phase induction motors, high starting torque motors, speed control, rheostatic method, pole changing method cascade control of speed, double cage. Pdf speed control of threephase induction motor based on v. Instructional objectives derivation of the expression for the gross torque developed as a function of slip. Note down the machine ratings and calculate rated current of the machine noload test.
And on the other hand, when designed to have a high impedance, the motor has an increased amount of torque in a lowspeed range. View notes l34nkdet ee nptel from ee 203 at iit kanpur. A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, elevators or electric multiple unit traction motors are used in electrically powered rail vehicles electric multiple units and other electric vehicles including electric milk floats, elevators, roller coasters, conveyors, and trolleybuses, as well as vehicles with. 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 currents and create a rotor field which will interact with the stator field and produce rotation. Apr 02, 2008 lecture series on basic electrical technology by prof. It is a 16 bit highperformance digital signal controller dsc. Characteristics of induction motors nidec corporation. The rotor will constantly be turning to align its magnetic field with that of the stator field. Record all nameplate information for the induction motor. Apr 18, 2020 ppt threephase induction motor electrical engineering ee notes edurev is made by best teachers of electrical engineering ee.
List and describe the more commonly used equipment in an electric substation. Nptel provides elearning through online web and video courses various streams. The above value becomes somewhat larger with small singlephase motors. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. 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. It is based on freescales 56f800e microcontrollers. Variable voltage variable frequency vf control theory an induction motor compared to a dc motor has some major advantages such as. Constructional features and principle of operation. Dec 29, 2017 apr 18, 2020 ppt three phase induction motor electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. Ac induction motors are also the most common motors used in main powered home appliances. Real life application a 3 phase induction motor or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque is.
A three phase induction motor runs on a three phase ac supply. Load tests on a three phase induction motor and measurement of the inrush current objectives. Start induction motor dynamic and steadystate performance of a. Sensored field oriented control of 3 phaseinduction motors bilal akin and manish bhardwaj abstract this application report presents a solution to control an ac induction motor using the tms320f2803x microcontrollers. Like any other type of electrical motor induction motor, a 3 phase induction motor is constructed from two main parts, namely the rotor and stator. The most common type of ac motor being used throughout the work today is the induction motor. The speed control of three phase induction motor is essential because the motor control industry is a dominant sector. They are found everywhere from a small workshop to a large manufacturing industry. And if it is answers generator it will be just above 1,500 rmp we will not discuss about induction generator only little about motor right. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm.
Differentiate between the various types of generating electric power stations. Nov 27, 2019 the three phase induction motor is the most widely used electrical motor. Tms320f2803x devices are part of the family of c2000 microcontrollers, which enable. The stator carries a 3 phase winding and is fed from a 3 phase supply. The 3 phase set of currents, each of equal magnitude and with a phase. Toshiba three phase induction motor nameplate continued fro second part basics of 3phase induction motor part 2 technical data to be specified by purchaser before purchasing a 3 phase induction motor. One singlephase wattmeter plus miscellaneous apparatus as needed. This document is highly rated by electrical engineering ee students and has been viewed 2495 times. Different speed control methods of induction motor are explained below. 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.
Perform an analysis on induction machines which is the most rugged and the most. The singlephase induction motor is much the same in construction as the threephase motor. Torquespeed characteristics of three phase squirrel cage. It is made up of a number of stampings, which are slotted to receive the windings. An induction motor essentially consists of two main parts. Induction motor 1 chapter 3 induction motor bee23 electrical machine power system 2 learning outcomes.
Types, construction and principle of operation, 3 phase induction motor, general phasor diagram, equivalent circuit, power and. Three phase ac induction motors are widely used in industrial and commercial applications. It supplies an induction motor ich has a full load speed of 144wh 0 rpm. Now suddenly e and machine was running at 1500 rpm close to that. It is the diagrammatic representation of the performance of the induction motor. Understand the principle and the nature of single phase and 3 phase induction machines. Circuit diagram for noload and blockedrotor test on 3 phase induction motor a. The basic idea of an electric motor is to generate two magnetic fields.
As induction motors are widely being used, their speed control may be required in many applications. At the end of the lecture, student should be able to. Single phase machines are restricted to small power levels. Mostafa elshahed objectives learn a brief history of the electrical power systems construction. The torque developed at the shaft of a 3phase motor is constant, less vibration in machinery powered by 3phase motors. As its name indicates stator is a stationary part of induction motor. These are of two types, squirrel cage and slip ring motors. When a motor is designed in such a way that impedance of the aluminum conductor of the rotor is. Circle diagram of an induction motor the circle diagram of an induction motor is very useful to study its performance under all operating conditions.
Sensored field oriented control of 3phase induction motors. This paper presents design and analysis of a three phase induction motor drive using igbt. Almost 80% of the mechanical power used by industries is provided by three phase induction motors because of its simple and rugged construction, low cost, good operating characteristics, the absence of commutator and good speed regulation. Working principle of three phase induction motor electrical simple. The major difference between them is that transformer is static in nature i.
When the supply is connected to the stator of a threephase induction motor, a rotating magnetic field is produced, and the rotor starts rotating and the induction motor starts. The construction of the circle diagram is based on the approximate equivalent circuit shown below. Umanand, principal research scientist, power electronics group, cedt, iisc bangalore. Ppt threephase induction motor electrical engineering. Module 8 threephase induction motor version 2 ee iit, kharagpur lesson 34 starting methods for singlephase induction motor version. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust.
Basic electrical technology nptel online videos, courses. A 3 phase ac induction motor can be controlled by varying its inputs according to a. So next we will be you know in another example other 3 or 4 examples and with that we will close the single phase. Ppt threephase induction motor electrical engineering ee. Lecture series on basic electrical technology by prof. To measure the inrush current when the motor starts. The three phase induction motor is the extensively used for various kinds of industrial drives. Construction of three phase induction motor electrical4u. There are two basic reasons for the use of single phase motors rather than 3 phase motors. Threephase induction motor, cage and wound slipring rotor, synchronous and rotor speed, slip, induced voltages in stator winding and rotor bar. In this case, power flows from the mechanical system, to the rotor circuit, then across the air gap to the stator circuit and external electrical system. Introduction this application note describes the design of a 3phase ac induction motor drive with volts per hertz control in closedloop vhz cl. And generally we will find it is a 4 pole machine, but the magnetic field. Vf speed control of 3 phase induction motor using space.
Rotating magnetic field in threephase induction motor nptel. Torquespeed characteristics of three phase squirrel cage induction motor aim to obtain the torquespeed characteristics tn r of a three phase squirrel cage induction motor using 1. A stator winding is placed in the stator of induction motor and the three phase. Two digital multimeters and fluke power quality meter with banana cables from the. View notes l29nkdet ee nptel from eso 203 at iit kanpur. Starting methods for singlephase induction motor nptel. The 3phase set of currents, each of equal magnitude and with a phase.
This rotating magnetic field has a speed which is known as the synchronous speed this rotating magnetic field induces the voltage in rotor bars and hence shortcircuit currents start flowing in the rotor bars. All we need to do is to keep daxis stator current constant. The stator of an induction motor is in principle, the same as that of a synchronous motor or generator. Slip of a power induction motor is 2 to 3% when the motor is operated under the rated load. When a 3 phase supply is given to the stator winding it sets up a rotating magnetic field in space. Introduction types of electrical machines types of 3 ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. There are two basic reasons for the use of singlephase motors rather than 3phase motors. How does an induction motor work how it works 3 phase motor ac motor duration. If the induction motor is operating in the linear magnetic region, the lm is constant. Working principle of three phase induction motor electrical. Simplified steadystateequivalent circuit of induction motor.
Umanand, principal research scientist, power electronics group, cedt, iisc bangalore for more detail. To obtain the load performance characteristics of a three phase squirrelcage induction motor. These motors are selfstarting and use no capacitor, start winding, centrifugal switch or other starting device. Then, equation 1 can be shown in terms of magnitude as. Fall 2005 ee595s electric drive systems 36 the plan continued achieving 14. Applications of three phase induction motors of size varying from half a kilowatt to thousands of kilowatts are numerous. One single phase wattmeter plus miscellaneous apparatus as needed.
The stator carries a 3phase winding and is fed from a 3phase supply. In this module we will be discussing the three phase induction machine. Threephase induction motor version 2 ee iit, kharagpur. Vvvf for controlling the speed of a threephase induction motor im by using vf control strategy in open loop mode. The 3 phase alternating current ac induction motors are mechanically simple, rugged, highly reliable, lower in cost per horsepower than dc motors and capable of more torque and efficiency than single phase ac motors. At the starting of the induction motor, stator windings are connected in star and, therefore, the voltage across each phase winding is equal to 1v 3 times the line voltage.
Difference is that transformer is an alternating flux machine while induction motor is rotating flux machine. Noload and blocked rotor test on an induction machine. Circle diagram of an induction motor its construction. Starting of an induction motor a three phase induction motor is self starting. Theory of star delta starter method of starting of induction motor. When a motor is designed in such a way that impedance of the aluminum conductor of the rotor is reduced, its efficiency is increased in a highspeed range. Find the percentage slip and number of poles of the induction motor. I styp is the starting current per phase with the stator windings. Lesson 32 torqueslip speed characteristics of induction motor im version 2 ee iit, kharagpur. Working principle of 3 phase induction motor is explained and from this, why induction motor is self starting, why rotor rotates in same direction as the rotating field are also answered. How a rotating magnetic field is formed in the air gap of a threephase induction motor, when the balanced winding of the stator is fed from a balanced supply. You should also make a dc measurement of stator winding linetoline resistance. Some singlephase induction motors are also called squirrel cage motors because of.
A 3 phase induction motor can be used for different applications with various speed and load requirements. Three phase induction motor drive using igbts and constant v. Analysis of 3 phase induction motor electrical machines. Noload and blocked rotor test on an induction machine aim. 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. So, now principle of induction motor right so, the operation of three phase induction. For reason of economy, most houses, offices and also rural areas are supplied with single phase a.