Let us consider the space around b0 and ccoil sides. The threephase induction motor is also called an asynchronous motor and it is the most commonly used type of motor in industrial applications. A simple method for operating the threephase induction motor on. The three phase induction motor is the most widely used electrical motor. The rotor is separated from the stator by a small airgap which ranges from 0. The stator circuit model of an induction motor consists of a stator phase winding resistance r 1, stator phase winding leakage reactance x 1 as shown in the circuit diagram below the no load current i 0 is simulated by a pure inductive reactor x 0. The circle diagram can be drawn for alternators, synchronous motors, transformers, induction motors. Analysis of 3 phase induction motor electrical machines. Iit should be checked that the motor selected has a sufficient overload capacity.
Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. This method is normally limited to smaller cage induction motors, because starting current can be as high as. Working principle of 3phase induction motor eduction motor works on the principle of electromagnetic induction. The rotor in an induction motor is not externally excited. Difference is that transformer is an alternating flux machine while induction motor is rotating flux machine. A threephase induction motor problem enginuity systems. List the causes that are responsible for nonstarting of a three phase induction. Learn for free, pay a small fee for exam and get a certificate. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. The conductors are heavy copper or aluminum bars fitted in each slot and shortcircuited by the end rings. The motor then produces a constant torque and not a pulsating torque as in other singlephase motors. Detailed explanations and references to other helpful documents gives. Simulation of three phase electronic soft starter using. Simulink model of three phase induction motor file.
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. The slip ringsbrushes allow external resistors to be connected in series with the winding. In a 3 phase ac induction motor, there are three stator windings, each usually in two halves, with the rotor winding shortcircuited by end rings. Threephase induction motors are run at a constant speed from no. Starting of 3 phase induction motors, high starting. Relative humidity shall be below 95%rh for totallyenclosed types, and below. An electrical motor is an electromechanical device which converts electrical energy into mechanical energy. Multi phase induction motors types, their working and. L direct on line starte it is simple and cheap starter for a 3phase induction motor. Abstract this research is purposed to establish a new method is good and simple to operate the 3phase induction motor on singlephase power by using the capacitors. The rotor of three phase induction motor consists of a cylindrical laminated core with parallel slots that can carry conductors. It supplies an induction motor ich has a full load speed of 144wh 0 rpm.
The electric drives with manual control can be as simple as a room fan. Vf control of three phase induction motor drive with different. This makes the induction motor robust, inexpensive and need less maintenance. This circuit 3 phase induction motor starter is one such starter. Three phase induction motors mcqs with explanatory answers. This means that there is no need for slip rings and brushes. Record all nameplate information for the induction motor.
The major difference between them is that transformer is static in nature i. The rotor winding terminals are connected to three slip rings which turn with the rotor. Introduction induction motors are employed in textile mills, agriculture and almost all the manufacturing industries to drive the loads because of its rugged construction and ease operation. These types of motors are known as selfstarting induction motors. Module 8 threephase induction motor version 2 ee iit, kharagpur lesson 34 starting. April 11, 20 8 of 10 vmot ll imot rpm torque vd id 208 v 1. Of all ac motor available, a poly phase induction motor is one which is most used in several kinds of industrial drives. Testing and inspection of surge protection devices. Type of ac servo motor 3 direct drive motor model name mdm series rangedia. Induction motor fault heading fault causes remedies induction motor a no supply voltage b driven equipment jam c motor shaft jammed. A wound rotor or slip ring motor has a 3phase winding, similar to the stator winding. An induction motor can therefore be made without electrical connections to the rotor.
Umanand, principal research scientist, power electronics group, cedt, iisc bangalore for more details on nptel visit. Pdf vf control of three phase induction motor drive with. Circle diagram of induction motor pdf conduct no load test and blocked rotor test on the induction motor and find out the per phase values of no load current i0, short. Stanway, the poly phase induction motor control by firing angle adjustment of silicon. 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. Low and high voltage three phase induction motors m line squirrel cage rotor horizontal date. Principle of onoff control technique integral cycle control the basic principle of onoff control technique is explained with reference to a single phase full wave ac voltage controller circuit shown below. One singlephase wattmeter plus miscellaneous apparatus as needed. Almost 80% of the mechanical power used by 3 phase induction motor pdf nptel. Fall 2005 ee595s electric drive systems 2 overview of strategies voltsperhertz control constant slip control fieldoriented control. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. When a three phase supply is given to the three phase stator winding, a rotating magnetic field of constant magnitude is produced as discussed earlier.
These currents act to produce mmf and ux along the axes of the respective coils. Construction of three phase induction motor electrical4u. This strange behavior of singlephase induction motor can be explained on the basis of doublefield revolving theory. View notes l34nkdet eenptel from ee 203 at iit kanpur. Find the percentage slip and number of poles of the induction motor. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. Three phase induction motors three phase induction motor three phase induction motors are the most widely used motor in industry induction motor is used as generator especially in the wind energy applications single phase induction motors are commonly used for household appliance the operation of the. You should also make a dc measurement of stator winding linetoline resistance. Specifically, the squirrel cage design is the most extensively used electric motor in industrial applications. Unit 3, 477 great south road penrose auckland new zealand tel. An induction motors rotor can be either wound type or squirrelcage type. 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.
Speed control of induction motors single phase and poly phase ac induction motor control. No name of experiment page no 1 to perform the brake test on a 3 slip ring induction motor and obtain its performance characteristics 2 to start a 3phase slip ring induction motor by rotor resistance starter. Lecture 10three phase induction motors electromechanical. The induction motor stator resembles the stator of a revolving field, three phase alternator. Frequency of supply to the induction motor f pn120 12. If the frequency of 3phase supply to the stator of 3phase induction motor is increased, then. 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. Fall 2005 ee595s electric drive systems 3 voltsperhertz control history. Nptel, online courses and certification, learn for free. Working principle of 3phase induction motor electrical. Approximate equivalent circuit of an induction motor. It gives the relationship between electrical rating and physical dimensions quantities output of a 3 phase im is.
The research was conducted at the laboratory of the electrical engineering of the. Assignment i visvesvaraya technological university. The motor then runs as a singlephase induction motor. 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. Torque production is governed by the angle formed between the rotor and the stator magnetic fluxes. You should also make a dc measurement of stator winding linetoline resistance using a dmm. Therefore, these motors are frequently used in industry. Theory and analysis of three phase induction motor using. Three phase induction motors mcqs with explanatory answers 1. List two problems each associated with over voltage and under voltage in a three phase induction motor. Maintenance and troubleshooting three phase induction motor.
The main body of the induction motor comprises of two major parts as shows. There are many methods in use to start 3phase induction motors. If a set of threephase current is added to these three coils. Explain how a rotating magnetic field is produced when the stator of a three phase induction motor is supplied from a symmetrical three phase supply. Resistance tests on resistance temperature detector rtd circuits. Three phase induction motor using written pole technology, main winding, exciter winding, control circuit for optimum utilization. Lecture 6 three phase induction motors cairo university. Chapter 3 induction motor and different speed control methods page no 3. A 3phase induction motor has two main parts i stator and ii rotor. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. Dq based modeling of three phase induction motor is presented in this model. Pdf this paper presents a vf control of induction motor with. Threephase induction motor, cage and wound slipring rotor, synchronous and rotor speed, slip, induced voltages in stator winding and rotor bar. They run at a constant speed from noload to the full load.
It is verylow cost but highly reliable gadget, besides being foolproof. As the current passes through the coils on opposite sides of the stator, a twopole electromagnet is established, creating a twopole motor. Vibration testing of motor after it has started running. There are two basic reasons for the use of singlephase motors rather than 3phase motors. Windingrotor arrangements for 3 phase induction machine three phase slip ring induction motor.
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