Record all nameplate information for the induction motor. The torque produced by three phase induction motor depends upon the following three factors. Cage induction machines institut fur elektrische energiewandlung. Induction motor formulas with calculations january 11. The starting of the motor requires the generation of a rotating magnetic flux similar to the rotating flux in a threephase motor. There are three basic types of small induction motors. Arrangement of stator in 3ph induction motor are given below. 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. Single phase induction motor the singlephase motor starting torque is zero because of the pulsating singlephase magnetic flux. Most ac power today is produced and distributed as threephase power where three sinusoidal voltages are generated out of phase with each other. Following data is taken from no load, locked rotor, and dc tests of a 3phase, wye connected 40 hp, 60 hz, 460 v, induction motor with a. With singlephase ac power there is only one single sinusoidal voltage. Pdf design and analysis of three phase induction motor. The rotor will constantly be turning to align its magnetic field with that of the stator field.
Ss synchronous speed rpm f frequency cycles second 60 p number of poles pole pairs. To this end, it will be assumed that the motor is a balanced three phase wye connected load and that you will therefore need to measure only one lineneutral voltage, only one line current, and only one phase power to characterize p in completely. Stardelta starting of a three phase induction motor 10. If the motor slip is known, the rotor speed can be expressed by the equation.
Rotor the rotor is a rotating part of induction motor. The current in each winding is 120 electrical degrees out of phase with the urrent in the other windings. The reply is to give a start point for your education, on this subject. You can then quantify the motor s partload by comparing the measured input power under. A 480v, 60 hz, 6pole, threephase, deltaconnected induction motor has the following. Rotor is at the stand still, while low voltage is applied to stator windings to circulate rated current. In the motor name plate the company provide the motor is 15 kw 3 phase induction motor. Three phase ac winding calculation linkedin slideshare. The ss is a function of the frequency of the power source and the number of poles pole pairs in the motor. Torque equation of three phase induction motor electrical4u.
The rotor is connected to the mechanical load through the shaft. The output of the motor drive is 3phase pulse width modulation pwm ranging in possible operation frequencies from 0hz to khz. You should also make a dc measurement of stator winding linetoline resistance. Index termscombined stardelta winding, combined wye delta winding. The threephase induction motor is the extensively used for various kinds of industrial drives. You will have to carry out the balance exploration yourself. The induction motor is made up of the stator, or stationary windings, and the rotor. For the rotor locked, s 1 so that the following equations can be written from the equivalent circuit of. The threephase induction motor is the extensively used for various.
Lecture 6 three phase induction motors cairo university. Design and analysis of three phase induction motor using computer program. A 3phase, y connected, 460 volt line to line, 25 horsepower, 60 hz, 8 pole induction motor has the following constants, in ohms per phase referred to the stator. The relationship to calculate the ss of an induction motor is. Locked rotor test the locked rotor test, like short circuit test on a transformer, provides the information about leakage impedances and rotor resistance. The three phase induction motor is the easiest motor of this type to understand so these notes start with that type. The three phase induction motor is the extensively used for various kinds of industrial drives. The induction motor block implements a three phase induction motor. Wiring methods nec 300 junction and cutout boxes nec 300. Three phase induction motor using written pole technology, main winding, exciter winding, control circuit for optimum utilization.
How an induction motor works by equations and physics. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. A single phase induction motor requires separate starting circuitry to provide a rotating field to. The motor drives a mechanical load at a speed of 1170 rpm. The magnetic field in the air gap from the voltage applied to the stator. The threephase induction motor is the easiest motor of this type to understand so these notes start with that type. Synchronous speed, frequency, and poles of the induction motor are related by the formula. 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, absence of commutator and good speed regulation. Definition of voltage and current transfer ratio to simplify equations. The synchronous speed of an induction motor depends on the frequency of the power supply and on the number of poles for which the motor. Find the starting current of 10 hp, three phase 220 v a class motor. Find the synchronous speed of 4 pole induction motor which operates at 60 hz. We will consider a 3phase, y connected machine, the.
Threephase ac winding calculations singlespeed windings kinds of diagrams this calculations program includes all necessary details for rewinding threephase motors. Regulation of 3phase alternator by zpf and asa methods 9. Induction motor theory quiz electrician practice tests. 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. If the threephase induction motor operated on power supply system, the motor can be analyzed by using characteristics of the. How to calculate the winding calculation of a single phase. Since these are vector equations the line current and power factor may be obtained from them. The 3phase set of currents, each of equal magnitude and with a phase.
Single phase motor schematics and working do follow the links as your question is too simple to make a proper re. It consists stator winding it is housed on the motor frame. The singlephase induction motor is more subtle and less efficient. The single phase induction motor is more subtle and less efficient. One singlephase wattmeter plus miscellaneous apparatus as needed. Calculate i the synchronous speed ii the rotor speed, when slip is 4% and iii. Theory and analysis of three phase induction motor using. For this example, refer to the motor equivalent circuit and calculations described above. Perphase equivalent circuit motor slip r 1 and r 2. Define the equivalent circuit of the transformer and calculate its efficiency and.
The three phase induction motor is the most widely used electrical motor. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. Find the voltage and horsepower of the motor and use the chart to. Find the phase of the motor, this will dictate which table you will go to for the flc. Ac induction motors are also the most common motors used in main powered home appliances. The basic idea of an electric motor is to generate two magnetic fields. They run at a constant speed from noload to the full load. To start induction motor by rotor resistance starter 8.
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