These motors are generally series wound armature and field winding are in series, and hence produce high starting torque see characteristics of dc motors here. An ac motor is an electric motor driven by an alternating current ac. A simple dc generator consists of a coil of insulated copper wire. The stator consists of a cylindrical frame and stator core. Construction, types and principle of operation of 3phase induction motors.
Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor. If a seried dc motor has a laminated stator frame, it can run effectively htt l d iki di iki di 667 from an ac supply as well as dc, this is the. A dc machine is an electromechanical energy alteration device. List the advantages and disadvantages of the two types of ac generators. In the accomplishment of this project successfully, many people have best owned upon me their blessings and the heart pledged support, this time i am utilizing to thank all the people who have been concerned with project. Speed control by frequency changing or variable frequency control method. An alternator or ac generator is an electrical machine which converts mechanical energy into alternating electric energy. 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. It is just made up of simple motor which run through servo mechanism. Describe the differences between the two basic types of ac generators. Scr silicon controlled rectifiers working,construction. In single phase induction motor, when a single phase supply is given to the stator winding, a pulsating magnetic field is produced and in a three phase induction motor, when three phase supply is given to three phase stator winding, a rotating magnetic field is produced. Universal motors are so named because they can run both on ac as well as dc.
The basic operating principle of dc motor is the same as other electromagnetic motors. The ac motors can be divided in two sub categories, synchronous motors and asynchronous motors. 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. Introduction to ac motor construction instrumentation. Therefore, a dc motor otherwise a dc generator can be generally called as a dc machine. A dc generator is also used as a dc motor by without changing its construction.
The theoretical speed of the rotor in an induction motor depends on the frequency of. Working of electric motor in the case of induction motor is little bit different from dc motor. Ac generator is an electrical machine which converts mechanical energy into electrical energy. The dc machines are classified into two types such as dc generator as well as dc motor. Unit 16 electric motors washington state university. In this chapter, we shall focus our attention on the construction, working and characteristics of commonly used singlephase motors. The threephase induction motor is the extensively used for various kinds of industrial drives.
The field windings of a series motors are connected in series with the armature windings. Session pdf for understand the working of dc motor. We also discuss the construction of a three phase motor including. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy. Ac motor construction threephase induction motors are commonly used in. The most common type of ac motor being used throughout the work today is the induction motor. Other motors that are included are 1phase induction motors, permanent synchronous motors and synchronous reluctance motors. The 3phase set of currents, each of equal magnitude and with a phase. In this session we will provide you some introduction to. Basically, an ac motor is a type of motor that is operated by an alternating current. The shape and size of these motors depends on their applications. The ac induction motor is the most used electrical motor in industrial applications worldwide.
Unit 16 electric motors objectives after studying this unit, the student will be able to state the purpose of an electric motor. This type of motor has three main parts, rotor, stator, and enclosure. In synchronous ac motors, the rotor turns at exactly the same speed as the rotating magnetic field. The shaded pole induction motor has no commutator, brushes, collector rings, contactors, capacitors or moving switch parts, so it is relatively cheaper, simpler and extremely rugged in construction and reliable. Threephase ac induction motors are commonly used in industrial applications. Describe the principle of magnetic induction as it applies to ac generators. A universal motor is a special type of motor which is designed to run on either dc or single phase ac supply. The absence of a centrifugal switch eliminates the possibility of motor failure due to faulty centrifugal switch mechanisms. The basic idea of an electric motor is to generate two magnetic fields. Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. Working of an ac electric generator lets look at the working of an ac electric generator suppose axle is rotated clockwise, so coil is also rotated clockwise, side ab of coil moves up and side cd moves down applying flemings right hand rule on side ab, force is upwards, magnetic field is left to right, so, current flows into the paper i. Construction of induction motor the three phase induction motor is a preferable type of motor.
It is mostly used in industrial drives because it is very reasonable and vigorous, economical and reliable. A typical servo motor comprises of three wires namely power, control, and ground. A universal motor works on either dc or single phase ac supply. Based on the construction there are two distinct types of ac servo motors, they are synchronous type ac servo motor and induction type ac servo motor. The combustion of fuel such as coal, petrol, diesel generates heat. A servo motor is an electrical device which can push or rotate an object with great precision. That is why, universal motors generally comes built into the device they are meant to drive. A universal motor has a high starting torque and variable speed characteristics. Pdf design and construction of induction motor thermal. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy to mechanical energy, and vice versa. The ac motor commonly consists of two basic parts, an outside stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft producing a second rotating magnetic field.
In this post we will discuss ac generator working and construction. Pdf rotor and stator temperature rise in induction motors is considered to be a major cause of motor insulation. It is also called asynchronous motor because it does not run at a synchronous speed. These types of motors are known as selfstarting induction motors.
That a motor is synchronous means that the motor shaft is rotating with the same speed as the rotating magnetic field inside the. Classification of motors electric motors alternating current ac motors direct current dc motors synchronous induction. An ac motor of this type may be part of a pump or fan or connected to some other form of mechanical equipment such as a winder, conveyor, or mixer. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. A universal motor is a special type of motor which is designed to run either on dc or single phase ac supply.
The coil is placed between the two poles of a strong horseshoe magnet. Describe the construction of a squirrel cage ac motor. An887, ac induction motor fundamentals microchip technology. Read more universal motor construction, working and application. Ac induction motors are also the most common motors used in main powered home appliances. Ac induction motors how ac motors work explain that stuff. Pdf construction and working of brushless dc motors. Shaded pole induction motors working and construction. Synchronous and asynchronous electricmotors the electric motor is an electromechanical continuous energy conversion equipment that converts electrical energy into electrical energy mechanical energy. Universal motor construction, working and application. This heat is supplied to a working substance at high temperature. Construction and working of dc motor electrical youtube. The rotor will constantly be turning to align its magnetic field with that of the stator field.
Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications. Working principle of dc generator, construction, diagram. The working principle of an alternator or ac generator is similar to the basic working principle of a dc generator. Understand the working and construction of a dc motor. A 3 phase induction motor can be used for different applications with various speed and load requirements. The working principle of a dc machine is when electric current flows through a coil within a magnetic field, and then the magnetic force generates a torque which rotates the dc motor. When current flows in the field winding, it produces an electromagnetic field. Induction motors in practice what controls the speed of an ac motor. The above diagram shows the configuration of stator winding. A universal motor is a singlephase series motor, which is able to run on either alternating current ac or direct current dc and the characteristics are similar for both ac and dc. It has the following main advantages and also some disadvantages. Construction and working of a dc motor 3d animation. Introduction to ac motors chapter ac motors pdf version.
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. Advantages and disadvantages of 3 phase induction motors. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. Dc machine construction, working, types, emf equation. Synchronoustype ac servo motor consist of stator and rotor. After the introduction of the dc electrical distribution system by edison in the united states, a gradual transition to the more economical ac system commenced. Motor speed relationship the synchronous speed of an ac motor is the speed of the rotating magnetic field set up by the stator winding synchronous speed rpm 120 x frequency divided by the number of poles. Electric generator class 10 working, principle, diagram. 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. It is logical that the least expensive, lowest maintenance type. Through this way the speed of a dc motor is controlled. Ac servo motor is an ac motor that includes encoder is used with controllers for givin g. Construction and principles of operation the slosyn motor is unique in that it has the capability of being operated as an ac synchronous, constant speed motor or as a phase switched dc stepper motor. An air conditioner collects hot air from a given space, processes it within itself with the help of a refrigerant and a bunch of coils and then releases cool air into the same space where the hot air had originally been collected.
Induction motors are by ac switchboard and it is a. Construction and working of dc motor electrical sharpedgelearning. Applications of threephase induction motors of size varying from half a kilowatt to. Introduction to ac motors ac motors electronics textbook. The theory used in the work was collected by studying literature on how electrical motors work, and by simplifying the. The rotor and stator windings are connected in parallel. Learn all the important areas of dc motor like the construction, working of dc motor and its principle. The design, construction, and the modes of operation are different. Construction of dc generator working principle of dc generator. Like most motors, an ac induction motor has a fixed outer portion, called the stator and a rotor that. Its operation is based on the principle that when a current carrying conductor is placed in a.
Because work is the product of force times the distance applied, work can be expressed in any compound unit of. Work is calculated by multiplying the force that causes the motion times the distance the force is applied. If you want to rotate and object at some specific angles or distance, then you use servo motor. Construction and working of 3 phase induction motor on ship.
In this work, digital temperature sensors are installed on rotor and stator windings. Synchronous and asynchronous electromechanicalsystems dr. The stator and rotor do the work, and the enclosure protects the stator and rotor. If motor is used is dc powered then it is called dc servo motor, and if it is ac. In this chapter, we shall focus our attention on the construction, working and. The construction of the slipring induction motor is exactly similar to the construction of. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. Lecture notes electrical machine ii bee 1401 page 1.
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