This book, therefore, targets the large body of workers engineers and students reasonably versed in engineering concepts who feel the need for practical insights relating to electric motors. The modules listed in the overview are linked to the corresponding pages. Synchronous and asynchronous electromechanicalsystems dr. There are many types of ac motors, but this course focuses on threephase induction motors, the most common type of motor used in industrial applications. Ac motors are efficient, durable, and quiet, making them a good choice for powering pumps, blowers, conveyors, and machine tools. Ac induction motors have some disadvantages as well. Ac motors are electric motors that rotate by using power from a commercial ac power supply. It may be necessary to replace an electric motor in. A motor that reverses the direction of an electrical current at regular times is called an alternating current motor, or more commonly known as an ac motor. 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. Electric motors convert electrical energy into mechanical energy.
Ac motors ac motor theory ac motor theory ac motors are widely used to drive machinery for a wide variety of applications. As in the dc motor, an ac motor also has a set of coils field and a rotor or armature, however, since there is a continuous current reversal, a commutating device is not needed. This section contains lecture notes in both pdf and powerpoint formats. Other members of the family are the directcurrent dc motor or generator, the induction motor or generator, and a number. This represents the number of ac power lines supplying the motor. Important questions and answers on electric motor with pdf to. This module describes the basic concepts of alternating current ac electrical circuits and discusses the associated terminology. Here are the types of questions on electric motors which are asked in an interview, question papers and other competitive exams as well. Other motors that are included are 1phase induction motors, permanent synchronous motors and synchronous reluctance motors. The only userserviceable parts on an ac motor are the brushes and the bearings.
Electrical motor electric motor electromagnetic induction. Types of ac motor definition and classification of ac motor. The types of ac motors mainly include synchronous, asynchronous, induction motor. The ac induction motor is the most used electrical motor in industrial applications worldwide. To understand how these motors operate, a knowledge of the basic theory of operation of ac motors is necessary. Far too often motors are mismatchedor oversizedfor the load they are intended to serve, or have been rewound multiple times. Three phase ac induction motors rated 1 hp 750 w and 25 w with small motors from cd player, toy and cddvd drive reader head traverse for higherpower applications where a polyphase electrical supply is available, the three. The handbook includes information on alternating current ac and direct current dc theory, circuits, motors, and generators. An indepth troubleshooting guide to help you with your ac electric motor issues. The electric current needed to turn the rotor is created by electromagnetic induction created by the stator winding.
Pdf nowadays, electric vehicles are regarded as the future for a sustainable automobile industry. An introduction to electrical motors basics course description. General purpose ac motors motors grainger industrial. Pdf \ file contains bookmarks, thumbnails, and hyperlinks to help you navigate through the document. Electrical machines generators and motors electrodynamics. Ac motors are known for their increased power output and efficiency, while dc motors are prized for their speed control.
Inverters are utilized when variablefrequency ac motors are supplied from a dc grid e. This loss applies whenever an imaginary component is present not just for motors. For motors falling outside this description, the more comprehensive model specifications below are recommended. Virtually all electrical motors use magnetic field rotation to spin their rotors. These ac electric motors consist of two electrical assemblies. The current flowing through the windings creates an electromagnet with a north pole and a south pole.
Threephase ac motors work on threephase electrical power, which is commonly found in largescale industrial applications. Two types of electric motors are used in electric vehicles to provide power to the wheels. Synchronous and asynchronous electricmotors the electric motor is an electromechanical continuous energy conversion equipment that converts electrical energy into electrical energy mechanical energy. Power factor correction electrical loss 2 between power plant and useful work output of motor was the transmission and transformer i2r and hysteresis losses resulting from the imaginary component of the power. Conversion of electrical power into mechanical power takes place in the rotating part of an electric motor i. For higherpower applications where a polyphase electrical supply is available, the three phase or polyphase ac induction motor is used. These speed controllers operate by varying the frequency of the power supply to an asynchronous threephase motor. In fact, ac and dc motor designs are very similar to their generator counterparts. Instrumentation and control tutorial 2 electric actuators this is a stand alone tutorial on electric motors and actuators. An ac motor of this type may be part of a pump or fan or. Transmission of electrical energy covered longer distances at a lower loss with alternating current. With that in mind, a finite element program is used in order to compare the performance of the two types of motor designs the im and pmac motor. This standard specification describes the requirements for the contractor to overhaul ashore in a suitable repair facility an alternating current ac induction or synchronous motor removed from a coast guard vessel. The theory used in the work was collected by studying literature on how electrical motors work, and by simplifying the.
Alternating current motors or ac motors are built on the principle that nikola tesla discovered in the late 19th century. The electric energy generated purchased by consumers for different needs. Mechanical energy what is an electric motor an electric motor is a device converting electrical energy into mechanical energy usually a torque. What is the difference between ac motors and dc motors. Preface the handbook of electric power calculationsprovides detailed stepbystep calculation procedures commonly encountered in electrical engineering.
Electric motors are the machines that convert electrical energy into the mechanical energy which further is used to drive a vehicle, plant and many more things around us. Some of the slides include animations, which can be seen by viewing the powerpoint file as a slide show. Determining electric motor load and efficiency most likely your operations motors account for a large part of your monthly electric bill. The complete guide to electrical insulation testing. Text headings in each module are linked to and f\ rom the table of contents for that module. Comparing ac induction with permanent magnet motors in. Understanding motor nameplate information nema vs iec standards. Dc motors, ac theory, ac power, ac generators, voltage regulators, ac. The ac motor is depends on the reversing magnetic field produced by alternating current through its stationary coils of wire to make the magnet rotate. Have you ever noticed what kind of motor drives the ceiling fan. They are easy to handle and have features that can be configured at. Electric motors and drives fundamentals, types and applications third edition austin hughes senior fellow, school of electronic and electrical engineering, university of leeds amsterdam boston heidelberg london new york oxford paris san diego san francisco singapore sydney tokyo newnes is an imprint of. Introduction to ac motors ac motors electronics textbook.
Read here to know about these electrical motors and their exhaustive classification. The stator in the electric motor generates the field current which rotates in a stable speed based on the ac frequency. Unit 16 electric motors washington state university. Their maximum speed is limited by the supply frequency a 50 hz supply limits the motor to about. Energy management guide for selection and use of singlephase motors. The 3phase set of currents, each of equal magnitude and with a phase.
Model repair specifications for low voltage induction motors. Sep 27, 2012 read about learning 101 basics of motors and motor controls. An ac motor is an electric motor driven by an alternating current ac. The national electrical manufacturers association nema specifies that every motor nameplate. Ac motors are generally reliable and last a long time before needing to be replaced. Types of ac motors classification and uses of alternating. Types of electric motors electric motors dc motors other motors h ac motors s unt motor separately excited induction motor stepper motor motor brushlessdc motor series motor hysteresis motor permanent magnet dc pmdc synchronous motor reluctance motor compounded motor universal motor. Singlephase ac motors use singlephase power that is typically found in homes.
The most obvious difference is the type of current each motor turns into energy, alternating current in the case of ac motors, and direct current in the case of dc motors. While dc motors require the use of brushes to make electrical contact with moving coils of wire, ac motors do not. A motor converts electrical energy into mechanical energy ac alternating current reverses poles of electromagnetic coil 120 times per sec 60hz coils wound into the stator of the motor create rotating magnetic field magnetic field passing through the conductors of the rotor induces current to flow. This interactive publication is created with flippingbook, a service for streaming pdfs online. Both types of electric motors are used in electric vehicles and have advantages and disadvantages, as shown here. The speed at which an induction motor operates is dependent upon the input power frequency and the number of electrical magnetic poles for which the motor is. Electrical tech note 103 agricultural engineering department michigan state university understanding electric motor nameplates1 understanding the information provided on an electric motor nameplate and how to use the information is important.
The rotor magnetic field may be produced by permanent magnets, reluctance. There are many different electrical motors, but this thesis and the course that was made, focus mostly on the ac induction motor. This conversion is usually obtained through the generation of a magnetic field by means of a current flowing into one or more coils. Motors and generators are the exact same device, but motors convert electrical energy into mechanical energy if the shaft on a motor is spun, a voltage is. Before we discuss these modifications, here it is essential to discuss what is the need and where do we need to do modifications. The speed of the motor is reduced with a compact gear box before driving the lead screw. There are many types of ac motors, but this course focuses on threephase ac induction motors, the most common type of motor used in industrial applications. The basic idea of an electric motor is to generate two magnetic fields. As we know, an electric motor plays a vital role in every sector of the industry, and also in a wide range of applications.
Different types of electric motors and their applications. Practical electric motor handbook pdf by irving m gottlieb. Understanding motor nameplate information nema vs iec. This magnetic flux is setup in the air gap of ac motor. Like most motors, an ac induction motor has a fixed outer portion, called the stator and a rotor that spins inside with a carefully engineered air gap between the two. General specification for consultants, industrial and municipal. Ac motors ac motors are used worldwide in many applications to transform electrical energy into mechanical energy. Jan 06, 2019 ac series motors are also known as the modified dc series motor as their construction is very similar to that of the dc series motor. Energy management guide for selection and use of fixed frequency medium ac squirrelcage polyphase induction motors. In fact, ac and dc motor designs are very similar to their generator counterparts identical for the sake of this tutorial, the ac motor being dependent. Electrical motor types classification and history of motor. Fundamentals of electrical drive controls josko deur and danijel pavkovi. The working of the synchronous motor mainly depends on the 3phase supply. Powering industry since replacing the steam engine from tiny hysteresis motors that drive electric clocks to huge synchronous motors that develop more than 50,000 hp, the alternating current ac motor has become an indispensable part of everyday life.
This type of motor uses opposing and attracting magnetic forces to propel the ac through the motor. Basic ac electrical generators 1 introduction faradays law. This course is intended to prepare the target persons with the ability to understand and recognize different types, components, theory of operation and applications of all electrical motors. In the year 1821 british scientist michael faraday explained the conversion of electrical energy into mechanical energy by placing a current carrying conductor in a magnetic field which resulted in the rotation of the conductor due to the torque produced by the mutual action of electrical current and field. This portable document format \ pdf \ file contains bookmarks, thumbnails, and hyperlinks to help you navigate through the document. Electrical motor free download as powerpoint presentation. Ac motor is an electrical device which converts electrical energy into mechanical energy. A basic rule of thumb is that in an ac motor, as in an ac generator used for industrial power production, the magnet is on the rotor and the current 1. The results presented in the remaining sections collectively represent. Transmission of electrical energy covered longer distances at a lower loss with alternating.
A singlephase ac induction motor depends on extra electrical components to produce this. A threephase ac induction motor is the only type where the rotating magnetic field is created naturally in the stator because of the nature of the supply. This section gives a very brief introduction to the most prevalent electrical actuators. There are a variety of types of electric motors are available in the market. The conversion of electrical energy to mechanical energy is through a coupling medium of magnetic flux. Since this motor has one north pole and one south pole, it is a 2pole motor. Ac motors are used worldwide in many applications to transform electrical energy into mechanical energy. Dc motors depend either on mechanical or electronic commutation to create rotating magnetic fields. There are many differences between ac and dc motors. Table of contents eep electrical engineering portal. The rotor will constantly be turning to align its magnetic field with that of the stator field. While dc motors need brushes to make electrical contact with moving coils of wire, ac motors do not. The principle of an ac motor is that electric current is applied to electromagnets, creating a rotating magnetic field to convert electrical energy to rotation mechanical energy. Unit 16 electric motors objectives after studying this unit, the student will be able to state the purpose of an electric motor.
An electric motor is a device converting electrical energy into mechanical energy usually a torque. Pdf ac motors for application in a commercial electric vehicle. The handbook contains a wide array of topics and each topic is written by an authority on the subject. Other motors that are included are 1phase induction motors, permanent synchronous. A useful introduction to electric motors electrical. Induction motors are among the most commonly used type of motor in the world. Like generators, electric motors consist of a stator and a rotor and the three ingredients. Generators, motors, transformers, and solenoids each use the principle of electromagnetism. Know where these different types of motors are used. 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.
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