CHAPTER 3 INDUCTION MOTOR AND DIFFERENT SPEED CONTROL METHODS


 John Copeland
 2 years ago
 Views:
Transcription
1 CHAPTER 3 INDUCTION MOTOR AND DIFFERENT SPEED CONTROL METHODS Page No 3.1 Introduction Three Phase Induction Motor Stator Rotor Working principle of three phase induction motor Equivalent Circuit Slip Different Speed Control Methods Stator voltage control method Frequency control method Volts Hertz (V/F) control method Conclusion 71 57
2 CHAPTER 3 INDUCTION MOTOR AND DIFFERENT SPEED CONTROL METHODS 3.1 Introduction This chapter describes the construction, principal of operation, start up consideration and the basic speed control methods for induction motor. 3.2 Three Phase Induction Motor (IM) The threephase induction motors are also called as asynchronous motors, which are most commonly used type of motor in industrial applications. In particular, the squirrelcage induction motors are widely used electric motor in home and industrial applications, because these machines are very economical, rugged and reliable. They are available in the ranges of Fractional Horse Power (FHP) to multimegawatt capacity. Fractional Horse Power motors are available in singlephase as well as polyphase (threephase).the three phase machines are used most often in variablespeed drives where the torque requirement is more. An induction motor or asynchronous motor is a type of alternating current motor where power is supplied to rotor by means of electromagnetic induction. An electric motor rotates because of magnetic force exerted between a stationary electromagnet called the stator and rotating electromagnet called the rotor. The current in stator side creates an electromagnetic field which interacts with the secondary to produce a resultant torque, transforming electrical energy into mechanical energy. The cross sectional view of induction motor and its various parts [4] are as shown in Fig 3.1 Construction: In this section, the construction details of induction motor are discussed. A three phase induction motor mainly consists of two parts, stator and rotor. Stator is the stationary 58
3 part while the rotor is the rotating part of the motor and they are separated by a small air gap depending on the rating of the motor. Fig. 3.1: Squirrelcage threephase Induction motor Fig. 3.2 Stator 59
4 3.2.1 Stator The stator is as shown in Fig 3.2, which consists of a steel frame which encloses a hollow cylindrical core made up of thin laminations of silicon steel to reduce eddy current and hysteresis loss. A large number of uniform slots are cut on the inner periphery of the core. The stator conductors are placed in these slots which are insulated from one another and also from the slots. These conductors are connected as a balanced three phase star or delta winding. The windings are wound for a definite number of poles depending on the requirement of speed. It is wound for more number of poles, if speed required is less and vice versa. According to the relation Ns = 120f / P (3.1) Where Ns is the synchronous speed in RPM f is the supply frequency P is the number of poles When a three phase supply is given to stator winding a magnetic field of constant magnitude and rotating at synchronous speed is produced. This rotating magnetic field is mainly responsible for producing the torque in the rotor, so that it can rotate at the rated speed Rotor The rotor is the rotating part of the induction motor and is mounted on the shaft of the motor to which any mechanical load can be connected. Based on the construction of the rotor, induction motors are broadly classified in two categories; squirrel cage motors and slip ring motors. The stator construction is the same in both motors. 60
5 Squirrel cage motors: Fig. 3.3: Squirrel cage type rotor Almost 90% of induction motors are squirrel cage motors. This is because the squirrel cage motor has a simple and rugged construction. Fig 3.3 shows the squirrel cage type rotor, it consists of cylindrical laminated core with axially placed parallel slots for carrying rotor conductors. The rotor conductors are heavy bars of copper or aluminium. Each slot carries a copper, aluminium or alloy bar. If the slots are semi closed, then these bars are inserted from the ends. These rotor bars are permanently shortcircuited at both ends by means of the end rings, thus short circuiting themselves at both the ends. As rotor bars are short circuited on themselves, it is not possible to add any external resistance in series with rotor circuit during starting. The slots are slightly skewed, which helps in two ways i.e. It reduces noise due to magnetic hum and makes motor run quietly. It reduces locking tendency between rotor and stator. Advantages of squirrel cage rotor: 1. It is simple in construction, rugged and can withstand rough handling. 61
6 2. Maintenance cost is low. 3. It has better efficiency and power factor. 4. A simple star delta starter is sufficient to start the rotor. 5. It is explosion proof as there are no slip rings and brushes. Slip ring motors: In the slip ring motor, the windings on the rotor are terminated to three insulated slip rings mounted on the shaft with brushes resting on them. This allows an introduction of an external resistor to the rotor winding. The external resistor can be used to boost the starting torque of the motor and change the speedtorque characteristic. When running under normal conditions, the slip rings are shortcircuited, using an external metal collar, which is pushed along the shaft to connect the rings. In normal conditions, the slip ring motor functions like a squirrel cage motor Working principle of three phase induction motor When a three phase supply is given to the three phase stator winding, a magnetic field of constant magnitude and rotating at synchronous speed N s is produced. This rotating magnetic field sweeps across the rotor conductors and hence an electromagnetic force (EMF) is induced in rotor conductors. As the rotor conductors are short circuited on themselves the induced EMF sets up a current in the rotor conductors in such a direction as to produce a torque, which rotates the rotor in same direction as magnetic field so that relative speed decreases. The speed of rotor gradually increases and tries to catch up with the speed of rotating magnetic field, but it fails to reach synchronous speed, because if it catches up with speed of magnetic field, relative speed becomes zero and hence no EMF will be induced in the rotor conductors, the torque becomes zero. Hence, rotor will not be able to catch up with the speed of magnetic field but rotates at a speed N r which is slightly less than the synchronous speed [3]. 62
7 3.2.4 Equivalent Circuit Fig.3.4 Per phase equivalent circuit of induction motor The equivalent circuit [3] is as shown in Fig From the equivalent circuit diagram the various power expressions can be written as follows: Input power = 3V s I s cos Φ (3.2) Stator copper loss = P ls = 3 I 2 SR s (3.3) Core Loss = (3.4) Power across air gap = p g = (3.5) Rotor copper loss: P lr = 3 R r (3.6) Output power: P o = P g  P lr = 3 R r ( ) (3.7) Since the output power is the product of developed torque T e and speed ω m, T e can be expressed as T e = T e = R r ( ) = (3.8) 63
8 From the equivalent circuit, the approximate equivalent circuit can be obtained as shown in Fig 3.5, where the core loss resistor R m has been dropped and the magnetizing inductance L m has been shifted to the input. This approximation is easily justified for an integral horsepower machine, where (R s + j L ls )<< L m [5]. The performance prediction by the simplified circuit typically varies within 5 percent from that of the actual machine Fig. 3.5 Approximate per phase equivalent circuit of IM In Figure 3.5, the current I r is figured out by: I r = (3.9) Substituting Equation (3.9) in (3.8) yields T e = (3.10) A further simplification of the equivalent circuit of Fig 3.4 can be made by neglecting the stator parameters R s and L ls. This assumption is not unreasonable for an integral horsepower machine, particularly if the speed is typically above 10 percent. Then, the equation (3.10) can be simplified as 64
9 T e = 3 ) (3.11) where, ω sl = sω e The air gap flux can be given by (3.12) in a lowslip region, equation (3.11) can be approximated as T e = (3.13) where, >> Equation (3.11 ) is important because it indicated that at constant flux, the torque T e is proportional to slip frequency, or at constant slip frequency, torque T e is proportional to Ψ 2 m Slip The slip can be defined as the difference between the synchronous speed and actual speed of the machine. It can be expressed in the percentage. Based on this slip speed, the voltage induced in the rotor winding changes, which in turn changes the rotor current and also the torque. As slip increases, the rotor current and the torque also increases. The rotor moves in the same direction as that of the rotating magnetic field to reduce the induced current (Lenz s law). The slip can be expressed as given below [1][2]: (3.14) or Slip S = = (3.15) or rotor speed N r = Ns (1S) (3.16) Synchronous speed is given by Ns = (3.17) Where P represents the number of poles and f is stator frequency in Hz 65
10 Therefore equation 3.16 becomes, Rotor speed N r = (1S) (3.18) Thus, the speed of an induction motor depends on slip S, stator frequency f and the number of poles P for which the windings are wound. 3.3 Different Speed Control Methods From equation 3.18, the speed of IM can be varied by varying the slip S or number of poles p or frequency of supply. The different methods of speed control of induction motor can be broadly classified in to scalar and vector control methods. In this work, scalar control methods are used. Hence only details of scalar methods are discussed here. The explanation of vector control method is beyond the scope of this thesis. The scalar methods of speed control [4] can be classified as Stator voltage control Frequency control Stator voltage and frequency control i.e Volts Hertz control Rotor voltage control The first three methods are the basic methods of speed control and are explained in detail as follows: Stator voltage control method A very simple and economical method of speed control is to vary the stator voltage at constant supply frequency. The threephase stator voltage at line frequency can be controlled by controlling the switches in the inverter. As seen from the equation (3.10) the developed torque is proportional to the square of the stator supply voltage and a reduction in stator voltage will produce a reduction in speed. Therefore, continuous speed control may be obtained by adjustment of the stator voltage without any alteration in the stator frequency. 66
11 T e = (3.19) The Torque speed curves with variable stator voltage [3] control are shown in Fig 3.6. Fig.3.6: SpeedTorque characteristics with variable stator voltage The salient features of stator voltage control method are: For lowslip motor, the speed range is very low. Not suitable for constanttorque load. Poor power factor. Used mainly in low power applications, such as fans, blowers, centrifugal pumps, etc. 67
12 3.3.2 Frequency control method The torque and speed of induction motors can be controlled by changing the supply frequency but keeping the voltage constant. If the frequency is decreased keeping voltage constant, then saturation of airgap flux takes place. At low frequency, the reactance will decrease and the motor current may be too high. If the frequency is increased above its rated value, then the air gap flux and rotor current decreases correspondingly, the developed torque also decreases. Due to these reasons this method of control is rarely used. The torque speed characteristics with frequency control [3] are shown in Fig.3.7. Fig.3.7 SpeedTorque characteristics with variable frequency control Volts Hertz (V/F) control method The constant V/F control method is the most popular method of Scalar control. If an attempt is made to reduce the supply frequency at the rated supply voltage, the air gap flux Ψ m will tend to saturate, causing excessive stator current and distortion of flux wave. 68
13 Therefore, the region below the base or rated frequency should be accompanied by the proportional reduction of stator voltage so as to maintain the air gap flux constant. If the ratio of voltage to frequency is kept constant, the flux remains constant. By varying the voltage and frequency the torque and speed can be varied. The torque is normally maintained constant while the speed is varied. This arrangement is widely used in the locomotives and industrial applications. The purpose of the volts hertz control scheme is to maintain the airgap flux of AC Induction motor constant in order to achieve higher runtime efficiency. The magnitude of stator flux is proportional to the ratio of stator voltage & the frequency. If ratio is kept constant the stator flux remains constant & motor torque will only depends upon slip frequency. In variablefrequency, variablevoltage operation of a drive system, the machine usually has low slip characteristics (i.e low rotor resistance), giving high efficiency. In spite of the low inherent starting torque for base frequency operation, the machine can always be started at maximum torque as indicated in Fig 3.8.The absence of high inrush starting current in a directstart drive reduces stress and therefore improves the effective life of the machine. By far the majority of variablespeed ac drives operate with a variablefrequency, variablevoltage power supply. Fig 3.8 shows the torquespeed characteristics [3] of the machine with constant V/F control method. Other than the variation in speed, the torquespeed characteristics of the V/F control reveal the following: The starting current is low. The stable operating region of the motor is increased. Instead of simply running at its base/ rated speed (N B ), the motor can be run typically from 5% of the synchronous speed (N S ) up to the base speed. The torque generated by the motor can be kept constant throughout this region. 69
14 Since almost constant rated torque is available over the entire operating range, the speed range of the motor becomes wider. User can set the speed as per the load requirement, thereby achieving the higher efficiency. One of the most advantages is soft start capability in which motors are ramped up to speed instead of being abruptly thrown on line. This useful feature reduces mechanical stresses on the motor and leads to lower maintenance cost as well as a longer motor life. Because of above reasons V/F control method is proposed in this work. Fig.3.8 SpeedTorque curves with constant V/F ratio 70
15 3.4 Conclusion The construction, different parts of induction motor i.e stator and rotor, different types of induction machines, advantages of squirrelcage induction motor over woundrotor induction motor, the working principle, equivalent circuit of induction motor, various power expressions, slip, the different speed control methods of induction motor and the speed v/s torque characteristics are discussed in this chapter. 71
8 Speed control of Induction Machines
8 Speed control of Induction Machines We have seen the speed torque characteristic of the machine. In the stable region of operation in the motoring mode, the curve is rather steep and goes from zero torque
More informationThe Polyphase Induction Motor
Experiment No. 4 The Polyphase Induction Motor The polyphase induction motor is the most commonly used industrial motor, finding application in many situations where speed regulation is not essential.
More informationUnit 33 ThreePhase Motors
Unit 33 ThreePhase Motors Objectives: Discuss the operation of wound rotor motors. Discuss the operation of selsyn motors. Discuss the operation of synchronous motors. Determine the direction of rotation
More informationDHANALAKSHMI COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING EE2302  ELECTRICAL MACHINES II UNITI SYNCHRONOUS GENERATOR
1 DHANALAKSHMI COLLEGE OF ENGINEERING DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING Constructional details Types of rotors EE2302  ELECTRICAL MACHINES II UNITI SYNCHRONOUS GENERATOR PART A 1.
More informationIntroduction. Threephase induction motors are the most common and frequently encountered machines in industry
Induction Motors Introduction Threephase induction motors are the most common and frequently encountered machines in industry  simple design, rugged, lowprice, easy maintenance  wide range of power
More informationSYNCHRONOUS MACHINES
SYNCHRONOUS MACHINES The geometry of a synchronous machine is quite similar to that of the induction machine. The stator core and windings of a threephase synchronous machine are practically identical
More information2. A conductor of length 2m moves at 4m/s at 30 to a uniform magnetic field of 0.1T. Which one of the following gives the e.m.f. generated?
Extra Questions  2 1. A straight length of wire moves through a uniform magnetic field. The e.m.f. produced across the ends of the wire will be maximum if it moves: a) along the lines of magnetic flux
More informationAC Induction Motor Slip What It Is And How To Minimize It
AC Induction Motor Slip What It Is And How To Minimize It Mauri Peltola, ABB Oy, Helsinki, Finland The alternating current (AC) induction motor is often referred to as the workhorse of the industry because
More informationThe Synchronous Machine
Experiment No. 5 The Synchronous Machine Synchronous ac machines find application as motors in constant speed applications and, when interfaced to the power source with a variablefrequency converter system,
More informationSynchronous motor. Type. Nonexcited motors
Synchronous motor A synchronous electric motor is an AC motor in which the rotation rate of the shaft is synchronized with the frequency of the AC supply current; the rotation period is exactly equal to
More informationSECTION 4 ELECTRIC MOTORS UNIT 17: TYPES OF ELECTRIC MOTORS
SECTION 4 ELECTRIC MOTORS UNIT 17: TYPES OF ELECTRIC MOTORS UNIT OBJECTIVES After studying this unit, the reader should be able to Describe the different types of open singlephase motors used to drive
More informationLab 14: 3phase alternator.
Lab 14: 3phase alternator. Objective: to obtain the noload saturation curve of the alternator; to determine the voltage regulation characteristic of the alternator with resistive, capacitive, and inductive
More informationMotor Fundamentals. DC Motor
Motor Fundamentals Before we can examine the function of a drive, we must understand the basic operation of the motor. It is used to convert the electrical energy, supplied by the controller, to mechanical
More informationDIRECT CURRENT GENERATORS
DIRECT CURRENT GENERATORS Revision 12:50 14 Nov 05 INTRODUCTION A generator is a machine that converts mechanical energy into electrical energy by using the principle of magnetic induction. This principle
More informationEquipment: Power Supply, DAI, Wound rotor induction motor (8231), Electrodynamometer (8960), timing belt.
Lab 13: Wound rotor induction motor. Objective: to examine the construction of a 3phase wound rotor induction motor; to understand exciting current, synchronous speed and slip in this motor; to determine
More informationInduction Motor Theory
PDHonline Course E176 (3 PDH) Induction Motor Theory Instructor: Jerry R. Bednarczyk, P.E. 2012 PDH Online PDH Center 5272 Meadow Estates Drive Fairfax, VA 220306658 Phone & Fax: 7039880088 www.pdhonline.org
More information13 ELECTRIC MOTORS. 13.1 Basic Relations
13 ELECTRIC MOTORS Modern underwater vehicles and surface vessels are making increased use of electrical actuators, for all range of tasks including weaponry, control surfaces, and main propulsion. This
More informationPrinciples of Adjustable Frequency Drives
What is an Adjustable Frequency Drive? An adjustable frequency drive is a system for controlling the speed of an AC motor by controlling the frequency of the power supplied to the motor. A basic adjustable
More informationAC Drive Theory and Application
AC Drive Theory and Application Application Guide AP4145E Effective May 28 Introduction Adjustable Frequency AC Drive System Description An adjustable frequency AC drive system consists of an ordinary
More informationAC Motor Speed. n s = synchronous speed (in RPM), f = frequency (in Hz), and p = the number of poles
AC Induction Motors Simplest and most rugged electric motor Consists of wound stator and rotor assembly AC in the primary member (stator) induces current in the secondary member (rotor) Combined electromagnetic
More informationIV. ThreePhase Induction Machines. Induction Machines
IV. ThreePhase Induction Machines Induction Machines 1 2 3 4 5 6 7 8 9 10 11 12 13 Example 1: A 480V, 60 Hz, 6pole, threephase, deltaconnected induction motor has the following parameters: R 1 =0.461
More informationAC Generators and Motors
AC Generators and Motors Course No: E03008 Credit: 3 PDH A. Bhatia Continuing Education and Development, Inc. 9 Greyridge Farm Court Stony Point, NY 10980 P: (877) 3225800 F: (877) 3224774 info@cedengineering.com
More informationAC Motors. Siemens STEP 2000 Course. STEP 2000 Courses distributed by
Siemens STEP 2000 Course AC Motors It's easy to get in STEP! Download any course. Hint: Make sure you download all parts for each course and the test answer form. Complete each chapter and its review section
More informationIntroduction. Upon completion of Basics of AC Motors you should be able to:
Table of Contents Introduction...2 AC Motors...4 Force and Motion...6 AC Motor Construction... 12 Magnetism... 17 Electromagnetism... 19 Developing a Rotating Magnetic Field...24 Rotor Rotation...29 Motor
More informationUSE OF ARNO CONVERTER AND MOTORGENERATOR SET TO CONVERT A SINGLEPHASE AC SUPPLY TO A THREEPHASE AC FOR CONTROLLING THE SPEED OF A THREEPHASE INDUCTION MOTOR BY USING A THREEPHASE TO THREEPHASE CYCLOCONVERTER
International Journal of Electrical Engineering & Technology (IJEET) Volume 7, Issue 2, MarchApril, 2016, pp.1928, Article ID: IJEET_07_02_003 Available online at http:// http://www.iaeme.com/ijeet/issues.asp?jtype=ijeet&vtype=7&itype=2
More informationINDUCTION REGULATOR. Objective:
INDUCTION REGULATOR Objective: Using a wound rotor induction motor an Induction Regulator, study the effect of rotor position on the output voltage of the regulator. Also study its behaviour under load
More informationPrinciples and Working of DC and AC machines
BITS Pilani Dubai Campus Principles and Working of DC and AC machines Dr Jagadish Nayak Constructional features BITS Pilani Dubai Campus DC Generator A generator consists of a stationary portion called
More informationEFFICIENCY COMPARISON OF MODERN VARIABLE SPEED DRIVE TECHNOLOGIES
EFFICIENCY COMPARISON OF MODERN VARIABLE SPEED DRIVE TECHNOLOGIES JUNE 1993 BY EDWARD C. LEE POWERTEC INDUSTRIAL CORPORATION Abstract: Brushless D.C. technology is new to the general industrial maketplace
More informationNO LOAD & BLOCK ROTOR TEST ON THREE PHASE INDUCTION MOTOR
INDEX NO. : M142 TECHNICAL MANUAL FOR NO LOAD & BLOCK ROTOR TEST ON THREE PHASE INDUCTION MOTOR Manufactured by : PREMIER TRADING CORPORATION (An ISO 9001:2000 Certified Company) 212/1, Mansarover Civil
More informationQuestion Bank. 1. Electromagnetism 2. Magnetic Effects of an Electric Current 3. Electromagnetic Induction
1. Electromagnetism 2. Magnetic Effects of an Electric Current 3. Electromagnetic Induction 1. Diagram below shows a freely suspended magnetic needle. A copper wire is held parallel to the axis of magnetic
More informationFREQUENCY CONTROLLED AC MOTOR DRIVE
FREQUENCY CONTROLLED AC MOTOR DRIVE 1.0 Features of Standard AC Motors The squirrel cage induction motor is the electrical motor motor type most widely used in industry. This leading position results mainly
More informationELECTRICAL ENGINEERING Vol. III  Induction Motor and SelfExcited Induction Generator  TzeFun Chan
INDUCTION MOTOR AND SELFEXCITED INDUCTION GENERATOR TzeFun Chan The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China Keywords: threephase induction motor, singlephase induction motor,
More informationAND8008/D. Solid State Control Solutions for Three Phase 1 HP Motor APPLICATION NOTE
Solid State Control Solutions for Three Phase 1 HP Motor APPLICATION NOTE INTRODUCTION In all kinds of manufacturing, it is very common to have equipment that has three phase motors for doing different
More informationModelling, Simulation and Performance Analysis of A Variable Frequency Drive in Speed Control Of Induction Motor
International Journal of Engineering Inventions eissn: 787461, pissn: 3196491 Volume 3, Issue 5 (December 013) PP: 3641 Modelling, Simulation and Performance Analysis of A Variable Frequency Drive
More informationChapter 4: DC Generators
Chapter 4: DC Generators Creating an AC Voltage The voltage produced in a DC generator is inherently AC and only becomes DC after rectification Consider an AC generator, consisting of a coil on the rotor
More information*ADVANCED ELECTRIC GENERATOR & CONTROL FOR HIGH SPEED MICRO/MINI TURBINE BASED POWER SYSTEMS
*ADVANCED ELECTRIC GENERATOR & CONTROL FOR HIGH SPEED MICRO/MINI TURBINE BASED POWER SYSTEMS Jay Vaidya, President Electrodynamics Associates, Inc. 409 Eastbridge Drive, Oviedo, FL 32765 and Earl Gregory,
More informationBasics of Electricity
Basics of Electricity Generator Theory PJM State & Member Training Dept. PJM 2014 8/6/2013 Objectives The student will be able to: Describe the process of electromagnetic induction Identify the major components
More informationProf. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
6 Synchronous motor 6.1 Principle of operation In order to understand the principle of operation of a synchronous motor, let us examine what happens if we connect the armature winding (laid out in the
More informationEquipment: Power Supply, DAI, Splitphase/Capacitor start motor (8251), Electrodynamometer (8960), timing belt.
Lab 10: Splitphase induction motor. Objective: to examine the construction of the splitphase motor; to learn its wiring connections; to observe its starting and running operations; to measure its starting
More informationchapter6 Electrical machines and motors Unit 1 outcome 6
Electrical machines and motors chapter6 Unit 1 outcome 6 The principles of magnetism are central to many of the tasks you will carry out as an electrician. Magnetism, like gravity, is a fundamental force.
More informationExperiment 1 The DC Machine
Experiment 1 The DC Machine ECEN 4517 R. W. Erickson and D. Maksimovic The purpose of this experiment is to become familiar with operating principles, equivalent circuit models, and basic characteristics
More informationControl circuit. gathering and reporting fault messages. carrying out of protective functions for the frequency converter and motor.
Control circuit The control circuit, or control card, is the fourth main component of the frequency converter and has four essential tasks: control of the frequency converter semiconductors. data exchange
More informationDC GENERATOR THEORY. LIST the three conditions necessary to induce a voltage into a conductor.
DC Generators DC generators are widely used to produce a DC voltage. The amount of voltage produced depends on a variety of factors. EO 1.5 LIST the three conditions necessary to induce a voltage into
More information% FULLLOAD AMPS % FULLLOAD TORQUE STARTING TORQUE
. When applying VARIABLE Frequency Drives(VFD), the speedtorque characteristics of an induction motor started at full voltage and operated on utility power should first be reviewed. Figure 1 shows the
More informationControl of Motor Characteristics by SquirrelCage Rotor Design
394 CHAPTER 7 INDUCTION MOTORS Control of Motor Characteristics by SquirrelCage Rotor Design The reactance X 2 in an induction motor equivalent circuit represents the referred form of the rotor s leakage
More informationElectrical Power & Machines
d.c. Machines a.c. Single & Three Phase Machines Dissectible Machines Single & Three phase Transformers Measurement & Control Power Electronics Conventional & Virtual (PC based) Instrumentation Renewable
More informationSpeed Control Methods of Various Types of Speed Control Motors. Kazuya SHIRAHATA
Speed Control Methods of Various Types of Speed Control Motors Kazuya SHIRAHATA Oriental Motor Co., Ltd. offers a wide variety of speed control motors. Our speed control motor packages include the motor,
More informationEquipment: Power Supply, DAI, Synchronous motor (8241), Electrodynamometer (8960), Tachometer, Timing belt.
Lab 9: Synchronous motor. Objective: to examine the design of a 3phase synchronous motor; to learn how to connect it; to obtain its starting characteristic; to determine the fullload characteristic of
More informationOnline efficiency diagnostic of three phase asynchronous machines from start up data
European Association for the Development of Renewable Energies, Environment and Power Quality International Conference on Renewable Energies and Power Quality (ICREPQ 09) Valencia (Spain), 15th to 17th
More informationTechnical Guide No. 100. High Performance Drives  speed and torque regulation
Technical Guide No. 100 High Performance Drives  speed and torque regulation Process Regulator Speed Regulator Torque Regulator Process Technical Guide: The illustrations, charts and examples given in
More informationSIMULATION AND SPEED CONTROL OF INDUCTION MOTOR DRIVES
SIMULATION AND SPEED CONTROL OF INDUCTION MOTOR DRIVES A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF Bachelor of Technology In ELECTRICAL ENGINEERING By AMITPAL SINGH I.S.
More informationEDEXCEL NATIONAL CERTIFICATE/DIPLOMA UNIT 5  ELECTRICAL AND ELECTRONIC PRINCIPLES NQF LEVEL 3. OUTCOME 3  MAGNETISM and INDUCTION
EDEXCEL NATIONAL CERTIFICATE/DIPLOMA UNIT 5  ELECTRICAL AND ELECTRONIC PRINCIPLES NQF LEVEL 3 OUTCOME 3  MAGNETISM and INDUCTION 3 Understand the principles and properties of magnetism Magnetic field:
More informationThreePhase Induction Motor
EXPERIMENT Induction motor ThreePhase Induction Motors 208V LL OBJECTIVE This experiment demonstrates the performance of squirrelcage induction motors and the method for deriving electrical equivalent
More informationAPPLICATION NOTE  017
APPLICATION NOTE  017 PWM Motor Drives Theory and Measurement Considerations Pulse Width Modulated (PWM) power electronic techniques represent a large and increasing proportion of modern power electronics.
More informationWe will discuss common industrial applications with guides for the proper use of electric motors on these.
INTRODUCTION: Baldor Electric Company has prepared this Specifiers Guide to help you cover all the bases when you are specifying electric motors. It will cover in a generic way most of the subjects which
More informationFunctions, variations and application areas of magnetic components
Westring 18 3314 Büren Germany T +49 951 60 01 0 F +49 951 60 01 3 www.schaffner.com energy efficiency and reliability 1.1 Transformers The transformer is one of the traditional components of electrical
More informationMotor/Transformer Winding Repair
Workshop Practice Title and topics of HKSE 1 03.1.1.01.1 Fundamentals of specific trade Workshop organisation, industrial safety, quality assurance, introduction to accident prevention 2 03.1.1.21.1 Preparation
More informationProf. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao. D.C Machines
D.C Machines 1 Introduction The steam age signalled the beginning of an industrial revolution. The advantages of machines and gadgets in helping mass production and in improving the services spurred the
More informationData Sheet. AC Industrial Electric Motors
Data Pack B Issued ovember 2005 1502325812 Data Sheet AC Industrial Electric Motors Standards organisations The RSABB range of ac induction motors is produced to common European standards, these being
More informationCHAPTER 4 DESIGN OF INTEGRAL SLOT AND FRACTIONAL SLOT BRUSHLESS DC MOTOR
47 CHAPTER 4 DESIGN OF INTEGRAL SLOT AND FRACTIONAL SLOT BRUSHLESS DC MOTOR 4.1 INTRODUCTION This chapter deals with the design of 24 slots 8 poles, 48 slots 16 poles and 60 slots 16 poles brushless dc
More informationWIND TURBINE TECHNOLOGY
Module 2.22 WIND TURBINE TECHNOLOGY Electrical System Gerhard J. Gerdes Workshop on Renewable Energies November 1425, 2005 Nadi, Republic of the Fiji Islands Contents Module 2.2 Types of generator systems
More informationMAGNETISM MAGNETISM. Principles of Imaging Science II (120)
Principles of Imaging Science II (120) Magnetism & Electromagnetism MAGNETISM Magnetism is a property in nature that is present when charged particles are in motion. Any charged particle in motion creates
More informationDOE FUNDAMENTALS HANDBOOK ELECTRICAL SCIENCE Volume 4 of 4
DOEHDBK1011/492 JUNE 1992 DOE FUNDAMENTALS HANDBOOK ELECTRICAL SCIENCE Volume 4 of 4 U.S. Department of Energy Washington, D.C. 20585 FSC6910 Distribution Statement A. Approved for public release;
More informationEquipment: Power Supply, DAI, Universal motor (8254), Electrodynamometer (8960), timing belt.
Lab 12: The universal motor. Objective: to examine the construction of the universal motor; to determine its noload and fullload characteristics while operating on AC; to determine its noload and fullload
More informationChapter 3: AC and DC Motors DC Motors: General Principles of Operation 83. Most DC motors also carry one of three duty ratings:
Chapter 3: AC and DC Motors DC Motors: General Principles of Operation 83 Amps/field amps: designations for armature and field winding amps, respectively. These ratings are needed when programming the
More informationFigure Notional Portion of a Shipboard Electric Power Generation System
AC SYCHROOUS GEERATORS Why do we study AC synchronous generators? The short answer is that 3phase AC generators are the workhorse of the power generation arena. Why? They are not as power limited as DC
More informationHow the efficiency of induction motor is measured?
How the efficiency of induction motor is measured? S. Corino E. Romero L.F. Mantilla Department of Electrical Engineering and Energy E.T.S.I.I. y T. Universidad de Cantabria Avda de Los Castros, 395 Santander
More informationC Standard AC Motors
C Standard AC Standard AC C1 Overview, Product Series... C2 Constant... C9 C21 C113 Reversible C147 Overview, Product Series Constant Reversible Electromagnetic Brake C155 Electromagnetic Brake
More informationPower Quality paper #4
THE BEHAVIOUR OF CONTACTORS DURING VOLTAGE DIPS by: IT De Villiers SYNOPSIS Electrically heldin contactors may drop out during voltage depressions. The time that contactors take to drop out depends on
More informationOutline. Turbine Generators. Generator History 3/25/2014
Turbine Generators Andrew Kusiak 2139 Seamans Center Iowa City, Iowa 522421527 andrewkusiak@uiowa.edu Tel: 3193355934 Fax: 3193355669 http://www.icaen.uiowa.edu/~ankusiak Outline Generators Synchronous
More informationDirect Current Motor Electrical Evaluation Using Motor Circuit Analysis
Direct Current Motor Electrical Evaluation Using Motor Circuit Analysis Howard W. Penrose, PhD ALLTEST Pro, LLC Old Saybrook, CT Introduction Electrical testing of Direct Current (DC) electric motors
More informationAN887. AC Induction Motor Fundamentals INTRODUCTION BASIC CONSTRUCTION AND OPERATING PRINCIPLE. Stator
AC Induction Motor Fundamentals AN887 Author: INTRODUCTION Rakesh Parekh Microchip Technology Inc. AC induction motors are the most common motors used in industrial motion control systems, as well as in
More informationName: Date: Regents Physics Mr. Morgante UNIT 4B Magnetism
Name: Regents Physics Date: Mr. Morgante UNIT 4B Magnetism Magnetism Magnetic Force exists b/w charges in motion. Similar to electric fields, an X stands for a magnetic field line going into the page,
More informationmaxon DC motor Permanent magnet DC motor with coreless winding
maxon DC motor Permanent magnet DC motor with coreless winding Design, Characteristics Stator: Magnetic circuit Rotor: Winding and current flow Operation principle Commutation: Graphite brushes, precious
More informationMotors and Generators
Motors and Generators Electromechanical devices: convert electrical energy to mechanical motion/work and vice versa Operate on the coupling between currentcarrying conductors and magnetic fields Governed
More informationSYNCHRONOUS MACHINE TESTING WITH MOTOR CIRCUIT ANALYSIS INSTRUMENTATION
SYNCHRONOUS MACHINE TESTING WITH MOTOR CIRCUIT ANALYSIS INSTRUMENTATION Introduction Howard W. Penrose, Ph.D., CMRP Vice President, Engineering and Reliability Services Dreisilker Electric Motors, Inc.
More informationElectrical Machines II. Week 1: Construction and theory of operation of single phase transformer
Electrical Machines II Week 1: Construction and theory of operation of single phase transformer Transformers Overview A transformer changes ac electric power at one frequency and voltage level to ac electric
More informationAC generator theory. Resources and methods for learning about these subjects (list a few here, in preparation for your research):
AC generator theory This worksheet and all related files are licensed under the Creative Commons Attribution License, version 1.0. To view a copy of this license, visit http://creativecommons.org/licenses/by/1.0/,
More information1. Title Electrical fundamentals II (Mechanics Repair and Maintenance)
1. Title Electrical fundamentals II (Mechanics Repair and Maintenance) 2. Code EMAMBG429A 3. Range The knowledge is needed for a wide range of aircraft repair and maintenance works,e.g. applicable to aircrafts,
More informationAPPLICATION NOTE Innovative shunt design techniques optimise power measurement accuracy
APPLICATION NOTE  012 Innovative shunt design techniques optimise power measurement accuracy Introduction Rapid developments in power conversion technologies combined with a need for better product efficiency
More informationADJUSTABLE FREQUENCY DRIVES APPLICATION GUIDE
ADJUSTABLE FREQUENCY DRIVES APPLICATION GUIDE Adjustable Frequency Drives Application Guide Table of Contents Introduction....................................................................................
More informationModule 7. Transformer. Version 2 EE IIT, Kharagpur
Module 7 Transformer Version EE IIT, Kharagpur Lesson 4 Practical Transformer Version EE IIT, Kharagpur Contents 4 Practical Transformer 4 4. Goals of the lesson. 4 4. Practical transformer. 4 4.. Core
More informationTHIS paper reports some results of a research, which aims to investigate the
FACTA UNIVERSITATIS (NIŠ) SER.: ELEC. ENERG. vol. 22, no. 2, August 2009, 227234 Determination of Rotor Slot Number of an Induction Motor Using an External Search Coil Ozan Keysan and H. Bülent Ertan
More informationElectrical Drives 1. Week 1: Introduction to drive systems
Electrical Drives 1 Week 1: Introduction to drive systems What Do we mean by Electrical Drive System? It is the study of the electric system involving controlling electric motors in both steady state and
More informationSection 10. Application Manual for NEMA Motors. Special Applications
Special Applications 1 Power Factor Correction 1 Methods of Starting 3AC Induction Motors 5 3 Duty Cycles and Inertia 3 4 Horsepower Determination 30 5 Formulas and General Data 34 Power Factor Correction
More informationHow to Turn an AC Induction Motor Into a DC Motor (A Matter of Perspective) Steve Bowling Application Segments Engineer Microchip Technology, Inc.
1 How to Turn an AC Induction Motor Into a DC Motor (A Matter of Perspective) Steve Bowling Application Segments Engineer Microchip Technology, Inc. The territory of highperformance motor control has
More information2. Permanent Magnet (De) Magnetization 2.1 Methodology
Permanent Magnet (De) Magnetization and Soft Iron Hysteresis Effects: A comparison of FE analysis techniques A.M. Michaelides, J. Simkin, P. Kirby and C.P. Riley Cobham Technical Services Vector Fields
More informationVFD 101 Lesson 4. Application Terminology for a VFD
VFD 101 Lesson 4 Application Terminology for a VFD This lesson covers the application terminology associated with a Variable Frequency Drive (VFD) and describes each term in detail. When applying a Variable
More informationThe following table shows approximate percentage wise the
SHORTCIRCUIT CALCULATION INTRODUCTION Designing an electrical system is easy and simple, if only the normal operation of the network is taken into consideration. However, abnormal conditions which are
More informationCOMPUTER AIDED ELECTRICAL DRAWING (CAED) 10EE65
COMPUTER AIDED ELECTRICAL DRAWING (CAED) EE Winding Diagrams: (i) DC Winding diagrams (ii) AC Winding Diagrams Terminologies used in winding diagrams: Conductor: An individual piece of wire placed in the
More informationChapter 4. Magnetic Materials and Circuits
Chapter 4 Magnetic Materials and Circuits Objectives List six characteristics of magnetic field. Understand the righthand rule for current and magnetic fluxes. Define magnetic flux, flux density, magnetomotive
More information1150 hp motor design, electromagnetic and thermal analysis
115 hp motor design, electromagnetic and thermal analysis Qasim Al Akayshee 1, and David A Staton 2 1 Mawdsley s Ltd., The Perry Centre, Davey Close, Waterwells, Gloucester GL2 4AD phone: +44 1452 888311
More informationDrives Low Voltage. Adjustable Frequency. Adjustable Frequency Drives Low Voltage 32.01. Contents
June 2006 Sheet 17.01 Adjustable Frequency Drives Low Voltage Contents Application Guide Basic Motor and Adjustable Frequency Drive Theory..................02 AC Motors...................................................02
More informationCHAPTER 5 SYNCHRONOUS GENERATOR
CHPTER 5 SYNCHRONOUS GENERTOR Summary: 1. Synchronous Generator Construction 2. The Speed of Rotation of a Synchronous Generator 3. The Internal Generated Voltage of a Synchronous Generator 4. The Equivalent
More informationGenerator Stator Protection, under/over voltage, under /over frequency and unbalanced loading. Ramandeep Kaur Aujla S.NO 250447392
1 Generator Stator Protection, under/over voltage, under /over frequency and unbalanced loading By Ramandeep Kaur Aujla S.NO 250447392 ES 586b: Theory and applications of protective relays Department of
More informationEvaluating Induction Motor Rotor Bars with Electrical Signature Analysis
Evaluating Induction Motor Rotor Bars with Electrical Signature Analysis Howard W Penrose, Ph.D., CMRP SUCCESS by DESIGN Reliability Services Hello and welcome to our presentation on Evaluating Induction
More information1. The diagram below represents magnetic lines of force within a region of space.
1. The diagram below represents magnetic lines of force within a region of space. 4. In which diagram below is the magnetic flux density at point P greatest? (1) (3) (2) (4) The magnetic field is strongest
More informationDirect Current Motors
Direct Current Motors DC MOTORS The DC machine can operate as a generator and as a motor. Chap 5. Electrical Machines by Wildi, 6 e Lecturer: R. AlbaFlores Alfred State College Spring 2008 When a DC machine
More informationHIGH SPEED PERMANENT MAGNET SYNCHRONOUS MOTOR / GENERATOR DESIGN FOR FLYWHEEL APPLICATIONS
HIGH SPEED PERMANENT MAGNET SYNCHRONOUS MOTOR / GENERATOR DESIGN FOR FLYWHEEL APPLICATIONS Aleksandr Nagorny, Ph.D. National Research Council Outline Introduction Selection of the Rated Point The major
More informationWound Rotor Induction Motors 412 poles, up to 8000 kw, 11500 HP
Wound Rotor Induction Motors 412 poles, up to 8000 kw, 11500 HP ABB The Preferred Partner Egypt Cement Corporation, a major cement manufacturer, has chosen ABB wound rotor motors for all key applications
More information