Introduction to induction motor instrumentation and. Its diameter is still vx01 and is parallel to the horizontal axis oc. To illustrate the simplicity of the ac induction motor. Circle diagram of induction motor simple steps to learn circle. The rotor of an induction motor can be a squirrel cage rotor or wound. 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. If we look at the voltage induced in these coils as phasors, the diagram looks as shown in g. In a 3ph induction motor if we shift the magnetising branch.
The basic idea of an electric motor is to generate two magnetic fields. As we know, the diagrammatic representation is easier compared to theoretical and mathematical descriptions. The motor circle diagram also known as a heyland, behrend, or ossanna diagram is simply a graphical representation of the locus of induction motor stator current from zero speed to synchronous speed. Actually, we do not have that much time or patience to go through the writings so we prefer diagrammatic. Nptel provides elearning through online web and video courses various streams. The magnetization current im flowing in the motors equivalent circuit fig. Download link is provided and students can download the anna university ee6504 electrical machinesii em ii syllabus question bank lecture notes syllabus part a 2 marks with answers part b 16 marks question bank with answer, all the materials are listed below for the students to make use of it and score good maximum marks with our study materials. Types and constructional features of 3phase induction motor. Starting of 3 phase induction motors, high starting. What is a circle diagram a circle diagram is a graphical representation of the performance of an electrical machine. Pdf ee6504 electrical machinesii emii books, lecture. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. Schematic diagram illustration instructions there are two parts lists to choose from depending upon the availability of 120vac or.
The heyland diagram is an approximate representation of circle diagram applied to induction motors, which assumes that stator input voltage, rotor resistance and rotor reactance are constant and stator resistance and core loss are zero. When w and wm are converted into cycles per second or hz and revolutions per minute respectively, we have. Types, construction and principle of operation, 3 phase induction motor, general phasor diagram, equivalent circuit, power and torque relations, condition for maximum torque, circle diagram. Coefficient of coupling, energy stored in coupled coils lecture 05. Positive current is said to ow in these coils when current ows out of the page in a. Getting expression for torque in terms of equivalent circuit parameters and supply voltage.
Ppt induction motor powerpoint presentation free to. Nptel, online courses and certification, learn for free. The circle diagram is a graphical solution of the motor equivalent circuit which traces the locus of stator current. Circle diagram of an induction motor the circle diagram of an induction motor is very useful to study its performance under all operating conditions. And its based on the approximate equivalent circuit before deepen in steps of drawing the diagram it. Computations and circle diagrams 15 b0 of the exciting circuit are assumed constant, then i0 and. The basic diagram view a shows a circle with two leads labeled t1 and t2.
There are two basic reasons for the use of singlephase motors rather than 3phase motors. The stator part of the equivalent circuit together with the magnetising branch can be replaced by a. To understand the circle diagram of induction motor we should first know what is the circle diagram. A three phase induction motor is running at a synchronous speed of 1500 rpm,the rotor runs. Slip is the ratio between the slip speed and synchronous speed. To build an ac permanent capacitor splitphase induction motor. To analyse the three phase induction motor performance using circle diagram we need to. You will understand the important phenomena that occur when you start a motor using either a directon. Induction motor circle diagrams gp technologies ltd. For most shore facility applications, this is the case. Fall 2005 ee595s electric drive systems 2 overview of strategies voltsperhertz control constant slip control fieldoriented control.
An induction motor also known as an asynchronous motor is a commonly used ac electric motor. Singlephase induction motor the winding used normally in the stator fig. The threephase induction motor is the extensively used for various kinds of industrial drives. Hence, we find that if an induction motor is tested at various loads, the. Just as in the threephase motor diagram, the motor shows the power supply lines as being identified with the t. The current of a series circuit of constant reactance and variable resistance lies in a circle of diameter, vx, where v is the voltage across the series circuit and x is the reactance. Circle diagram 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. A circle diagram is a graphical representation of the performance of an electrical machine. Learn for free, pay a small fee for exam and get a certificate. Ac induction motors are also the most common motors used in main powered home appliances. It is the diagrammatic representation of the performance of the induction motor. The circle diagram can be drawn for alternators, synchronous motors, transformers, induction motors.
More precisely, you will be familiar with the characteristics of directonline starters and soft starters. 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. Generally three phase induction motor is treated as rotating transformer. Single phase induction motors have very high starting torque b. Learning objectives computations and circle diagrams. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. Lecture 53 exact power flow diagram and circle diagram lecture 54 circle diagram continued.
The concept of the circle diagram was conceived in the late 19th century, but is today no longer commonly utilized by engineers. Development of equivalent circuit of the motor when it runs with a slip. Induction machines guru nanak dev engineering college. Singlephase induction motor, starting torque, main and auxiliary windings, starting methods, splitphase, capacitor type, motor with capacitor startrun. Fall 2005 ee595s electric drive systems 3 voltsperhertz control history. The power flow diagram of an induction motor is shown below. In general, the induction motor is cheaper and easier to maintain compared to other alternatives. Slip line lecture 56 circle diagram from test data lecture 57 starting of 3 phase induction motor introduction lecture 58 dol and reactor starting lecture 59 dol and auto transformer starting lecture 60.
The circle diagram means that it is figure or curve which is drawn has a circular shape. The torque produced by a squirrel cage induction motor depends on irrespective of the supply frequency a mechanical load b supply voltage c rotor resistance d slip speed. The construction of the circle diagram is based on the approximate equivalent circuit shown below. It is commonly used to illustrate the performance of transformers, alternators, synchronous motors, and induction motors. How to construct circle diagram of induction motor source. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. Power flow diagram of induction motor explains the input given to the motor, the losses occurring and the output of the motor. The data below give the measurements of line current, voltage and reading of two wattmeters connected to measure the input.
Power flow diagram and losses of induction motor circuit. You should also make a dc measurement of stator winding linetoline resistance using a dmm. Lecture 6 three phase induction motors cairo university. 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.
Pdf computeraided teaching using matlabsimulink for. Threephase induction motor starters labvolt threephase induction motor starters. Circle diagram of induction motor simple steps to learn. In many cases, the singlephase motors on board a ship will be wired into the lighting distribution. The circle diagram is a graphic representation of the performance of the machine and its drawn in terms of the locus of the input voltage and current. Explain how the performance of induction motor can be predicted by circle diagram. The motor is mounted in a test rig that allows one to control the torque applied to the motor shaft and to measure both rpm and torque. The induction motor is made up of the stator, or stationary windings, and the rotor.
The 3phase set of currents, each of equal magnitude and with a phase. It is very useful to study the performance of an electric machine under a large variety of operating conditions. Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. The circle diagram of an induction motor is very useful to study its performance under all operating conditions. Circle diagram of an induction motor its construction. Draw the circle diagram for a 3phase, meshconnected, 22. The input power given to an induction motor is in the form of threephase voltage and currents.
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