This final thesis will mostly be dedicated to induction motors but also to synchronous permanent magnet and reluctance motors. There are two basic reasons for the use of singlephase motors rather than 3phase motors. Induction motors are referred to as asynchronous motors because they operate at a speed less than their synchronous speed. The theory used in the work was collected by studying literature on how electrical motors work, and by simplifying the.
The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. Speed control of an induction motor there is a various method of speed control of an induction motor. This application note discusses the basics of an ac induction motor. From the equation 1 it is clear that the motor speed can be changed by a change in frequency f, a number of poles p, and slip s. The locked rotor test is made at 15 hz to minimize the errors due to saturation and skin effects.
Fall 2005 ee595s electric drive systems 3 voltsperhertz control. Starting method for induction motors a 3phase induction motor is theoretically self starting. The threephase induction motor is the extensively used for various kinds of industrial drives. Uses soft magnet rotor that is magnetized by the application of current in the stator coils 3. Apr 02, 2008 lecture series on basic electrical technology by prof. Singlephase induction motor threephase induction motor singlephase induction motor there are probably more singlephase ac induction motors in use today than the total of all the other types put together. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. If an induction motor with certain ratio of rotor to stator slots, runs at 17 of the normal. Determine the motor parameters and the total core, friction and windage losses. 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. Pdf electromagnetism lecture notes university of cambridge. Induction motors and transformers both im and transformer works on the principle of induced voltage transformer. The electric energy generated purchased by consumers for different needs. Siemens circuit breakers siemens switch rotary 3pole siemens motor siemens induction motor shunt trip cqda2 shunt trip breaker siemens circuit breaker nema three phase induction motor text.
The stator works as the primary while the rotor works as the secondary. It is based on freescales 56f800e microcontrollers. The rotor will constantly be turning to align its magnetic field with that of the stator field. It is logical that the least expensive, lowest maintenance type motor should be used most often. Induction motors despite the fact that the threephase motor has more phases than the singlephase motor, the singlephase motor is a much more complex machine. Woundrotor induction motors are more expensive they require much more maintenance because of the.
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. The induction machine behaves like a transformer, transferring electrical energy from the stator to the rotor. Department of electrical engineering dit, university, dehradun, uttarakhand references. A rotating magnetic field is set up on the stator by using distributed windings and a 3phase ac. The electromagnetism lecture notes is a book to provide an introduction to electromagnetism for electrical and electronics engineers. Induction machines notes from jane courtney operation the induction machine behaves like a transformer, transferring electrical energy from the stator to the rotor. Induction motor basics, single phase and three phase. Record all nameplate information for the induction motor. The induction motor cannot make a quickreversal run because of. The disadvantage of this type of rotor is that the motor behavior cannot be altered by connecting anything to the rotor there are no rotor terminals.
By far the most commonly used ac motor is the induction motor. 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. Syllabus of bachelor of technology in electrical engineering 4th semester. Three phase induction motor model design and performance analysis in ansys rmxprt. It is logical that the least expensive, lowest maintenance type. The rotor of an induction motor can be a squirrel cage rotor or wound. Fall 2005 ee595s electric drive systems 36 the plan continued achieving 14.
Scalar control is the term used to describe a simpler form of motor control, using nonvectorcontrolled. An843, speed control of 3phase induction motor using. Lecture series on basic electrical technology by prof. Moduleiv 10 hours single phase induction motor, theory of operation double revolving field theory, equivalent circuit, determination of parameters methods of starting, split phase starting, repulsion starting, shaded pole starting, performance characteristics. It is this feature that makes induction machine suitable for use even in hazardous environments and reliable operation is achieved. Types, construction and principle of operation, 3 phase induction motor, general phasor diagram, equivalent circuit, power and torque.
Fall 2005 ee595s electric drive systems 2 overview of strategies voltsperhertz control constant slip control fieldoriented control. Extending binary properties to nary properties 12 8. An induction motor can therefore be made without electrical connections to the rotor. An induction motor im is a type of asynchronous ac motor where power is supplied to. The alternating current ac induction motor is one of the most rugged and most widely used machines in industry. A 3 phase induction motor can be used for different applications with various speed and load requirements. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. 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.
A motor with only armortisseur windings is called an induction motor. The singlephase induction motor is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth. Several additional components are necessary to operate the singlephase motor. The stator separate from rotor by small air gap have ranges from 0. If an induction motor with certain ratio of rotor to stator slots, runs at 17 of the normal speed, the phenomenon will be termed as. Other motors that are included are 1phase induction motors, permanent synchronous motors and synchronous reluctance motors. Squirrel cage wound rotor with slip rings the rotating magnetic field the basic idea of an electric motor is to generate two magnetic fields. Starting of 3 phase induction motors, high starting torque motors, speed. The supply is connected to the stator and the rotor received power by induction caused by the stator rotating flux, hence the motor obtains its name induction motor. Lecture notes electrical machine ii bee 1401 page 1. An induction motor is the most modest electrical machine from constructional point of view, in the majority of the cases. The motor with national specifications is of heatproof class 120 e. The induction motor is made up of the stator, or stationary windings, and the rotor.
In general, the induction motor is cheaper and easier to maintain compared to other alternatives. The stator of an induction motor consists of 3phase windings, which when connected to a 3phase supply creates a rotating magnetic field. Induction motor works on the principle of induction where electromagnetic field is induced into the rotor when rotating magnetic field of stator cuts the. In this application note, we will generate a third pwm in software, using a general purpose timer and an io pin resource that are readily available on the picmicro microcontroller. The rotor of the squirrel cage three phase induction motor is cylindrical in shape and have slots on its periphery.
There are two major components of an ac induction motor. Induction motor notes electrical components electric power. Short question answers for 3 phase induction motor. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. Introduction this application note describes the design of a 3phase ac induction motor drive with volts per hertz control in closedloop vhz cl. Draw the approximate equivalent circuit for the motor lockrotor noload dc test v line 36. The induction motor cannot make a quickreversal run because of the torque acting in the opposite. Singlephase motors have only two power source supply lines connected. Induction motor theory jerry bednarczyk, pe course content introduction the ac induction motor is well suited to applications requiring constant speed operation. An843, speed control of 3phase induction motor using pic18 mcus.
Principle of operation of single phase induction motor. The ac induction motor is the most used electrical motor in industrial applications worldwide. This application note also covers the basics of induction motors and different types of induction motors. Physical layout of induction motor in an induction motor induction refers the field in the rotor is induced by the stator currents and asynchronous refers that the rotor speed is not equal to the stator speed. Three phase induction motor introduction the induction machine was invented by nikola tesla in 1888. If the induction motor is operating in the linear magnetic region, the lm is constant. Syllabus of bachelor of technology in electrical engineering 4th semester electrical machinesii. The induction motor essentially consists of two parts. This will link and cut the rotor conductors which in turn will induce a current in the rotor conductors and. Simplified steadystateequivalent circuit of induction motor. Ac induction motors are also the most common motors used in main powered home appliances. Synchronous and asynchronous electromechanicalsystems dr. Note that the torque exerted upon the motor by the dynamometer is indicated by the appropriate scale on the dynamometer circumference.
The major difference between them is that transformer is static in nature i. Rewinding of motors pdf the information in this report and the good practice guide to maintain motor efficiency part 2 was. Nov 03, 2019 an induction motor also known as an asynchronous motor is a commonly used ac electric motor. Then, equation 1 can be shown in terms of magnitude as. Right from its inception its ease of manufacture and its robustness have made it a very strong candidate for electromechanical energy conversion. These are compiled by david tong, department of applied mathematics and theoretical physics, university of cambridge. Synchronous and asynchronous electricmotors the electric motor is an electromechanical continuous energy conversion equipment that converts electrical energy into electrical energy mechanical energy.
The basic idea of an electric motor is to generate two magnetic fields. An887, ac induction motor fundamentals microchip technology. The maximum torque that the motor can develop typically 2. There are two types of induction motors, one with wound type rotor, also called slipring motor and another one with squirrelcage rotor. Applications of single phase induction motor these are used in low power. The rotor has salient poles and a cage so that it starts like an induction motor, and runs like a synchronous motor. The rotor speed of an induction motor is given by the equation shown below. All we need to do is to keep daxis stator current constant. Umanand, principal research scientist, power electronics group, cedt, iisc bangalore for more detail. It is available from fractional horsepower ratings to. You should also make a dc measurement of stator winding linetoline resistance using a dmm. 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. The 3phase set of currents, each of equal magnitude and with a phase.
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