Analysis of Induction Motor Torque
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Motion Projectile Motion,And Straight Linemotion, Differences Between the Similaritiesand 2 CHAPTER 2 Acceleration Make Thefollowing As Youreadthe ●
026_039_Ch02_RE_896315.qxd 3/23/10 5:08 PM Page 36 User-040 113:GO00492:GPS_Reading_Essentials_SE%0:XXXXXXXXXXXXX_SE:Application_File chapter 2 Motion section ●3 Acceleration What You’ll Learn Before You Read ■ how acceleration, time, and velocity are related Describe what happens to the speed of a bicycle as it goes ■ the different ways an uphill and downhill. object can accelerate ■ how to calculate acceleration ■ the similarities and differences between straight line motion, projectile motion, and circular motion Read to Learn Study Coach Outlining As you read the Velocity and Acceleration section, make an outline of the important information in A car sitting at a stoplight is not moving. When the light each paragraph. turns green, the driver presses the gas pedal and the car starts moving. The car moves faster and faster. Speed is the rate of change of position. Acceleration is the rate of change of velocity. When the velocity of an object changes, the object is accelerating. Remember that velocity is a measure that includes both speed and direction. Because of this, a change in velocity can be either a change in how fast something is moving or a change in the direction it is moving. Acceleration means that an object changes it speed, its direction, or both. How are speeding up and slowing down described? ●D Construct a Venn When you think of something accelerating, you probably Diagram Make the following trifold Foldable to compare and think of it as speeding up. But an object that is slowing down contrast the characteristics of is also accelerating. Remember that acceleration is a change in acceleration, speed, and velocity. -
Frames of Reference
Galilean Relativity 1 m/s 3 m/s Q. What is the women velocity? A. With respect to whom? Frames of Reference: A frame of reference is a set of coordinates (for example x, y & z axes) with respect to whom any physical quantity can be determined. Inertial Frames of Reference: - The inertia of a body is the resistance of changing its state of motion. - Uniformly moving reference frames (e.g. those considered at 'rest' or moving with constant velocity in a straight line) are called inertial reference frames. - Special relativity deals only with physics viewed from inertial reference frames. - If we can neglect the effect of the earth’s rotations, a frame of reference fixed in the earth is an inertial reference frame. Galilean Coordinate Transformations: For simplicity: - Let coordinates in both references equal at (t = 0 ). - Use Cartesian coordinate systems. t1 = t2 = 0 t1 = t2 At ( t1 = t2 ) Galilean Coordinate Transformations are: x2= x 1 − vt 1 x1= x 2+ vt 2 or y2= y 1 y1= y 2 z2= z 1 z1= z 2 Recall v is constant, differentiation of above equations gives Galilean velocity Transformations: dx dx dx dx 2 =1 − v 1 =2 − v dt 2 dt 1 dt 1 dt 2 dy dy dy dy 2 = 1 1 = 2 dt dt dt dt 2 1 1 2 dz dz dz dz 2 = 1 1 = 2 and dt2 dt 1 dt 1 dt 2 or v x1= v x 2 + v v x2 =v x1 − v and Similarly, Galilean acceleration Transformations: a2= a 1 Physics before Relativity Classical physics was developed between about 1650 and 1900 based on: * Idealized mechanical models that can be subjected to mathematical analysis and tested against observation. -
Sri Venkateswara College of Engineering and Technology Department of Electrical & Electronics Engineering EE 6504-Electrical
Sri Venkateswara College of Engineering and Technology Department of Electrical & Electronics Engineering EE 6504-Electrical Machines-II UNIT-I 1. Why a 3-phase synchronous motor will always run at synchronous speed? Because of the magnetic coupling between the stator poles and rotor poles the motor runs exactly at synchronous speed. 2. What are the two classification synchronous machines? The classification synchronous machines are: i. Cylindrical rotor type ii. Salient pole rotor type 3. What are the essential features of synchronous machine? i. The rotor speed is synchronous with stator rotating field. ii. Varying its field current can easily vary the speed. iii. It is used for constant speed operation. 4. Mention the methods of starting of 3-phase synchronous motor. a. A D.C motor coupled to the synchronous motor shaft. b. A small induction motor coupled to its shaft.(pony method) c. Using damper windings –started as a squirrel cage induction motor. 5. What are the principal advantages of rotating field system type of construction of synchronous machines? · Form Stationary connection between external circuit and system of conditions enable the machine to handle large amount of volt-ampere as high as 500 MVA. · The relatively small amount of power required for field system can be easily supplied to the rotating field system via slip rings and brushes. · More space is available in the stator part of the machine for providing more insulation to the system of conductors. · Insulation to stationary system of conductors is not subjected to mechanical stresses due to centrifugal action. · Stationary system of conductors can easily be braced to prevent deformation. -
Direct Torque Control of Induction Motors
DIRECT TORQUE CONTROL FOR INDUCTION MOTOR DRIVES MAIN FEATURES OF DTC · Decoupled control of torque and flux · Absence of mechanical transducers · Current regulator, PWM pulse generation, PI control of flux and torque and co-ordinate transformation are not required · Very simple control scheme and low computational time · Reduced parameter sensitivity BLOCK DIAGRAM OF DTC SCHEME + _ s* s j s + Djs _ Voltage Vector s * T + j s DT Selection _ T S S S s Stator a b c Torque j s s E Flux vs 2 Estimator Estimator 3 s is 2 i b i a 3 Induction Motor In principle the DTC method selects one of the six nonzero and two zero voltage vectors of the inverter on the basis of the instantaneous errors in torque and stator flux magnitude. MAIN TOPICS Þ Space vector representation Þ Fundamental concept of DTC Þ Rotor flux reference Þ Voltage vector selection criteria Þ Amplitude of flux and torque hysteresis band Þ Direct self control (DSC) Þ SVM applied to DTC Þ Flux estimation at low speed Þ Sensitivity to parameter variations and current sensor offsets Þ Conclusions INVERTER OUTPUT VOLTAGE VECTORS I Sw1 Sw3 Sw5 E a b c Sw2 Sw4 Sw6 Voltage-source inverter (VSI) For each possible switching configuration, the output voltages can be represented in terms of space vectors, according to the following equation æ 2p 4p ö s 2 j j v = ç v + v e 3 + v e 3 ÷ s ç a b c ÷ 3 è ø where va, vb and vc are phase voltages. -
The Fundamentals of Ac Electric Induction Motor Design and Application
THE FUNDAMENTALS OF AC ELECTRIC INDUCTION MOTOR DESIGN AND APPLICATION by Edward J. Thornton Electrical Consultant E. I. du Pont de Nemours Houston, Texas and J. Kirk Armintor Senior Account Sales Engineer Rockwell Automation The Woodlands, Texas Edward J. (Ed) Thornton is an Electrical Electrical Mechanical Consultant in the Electrical Technology Coupling System Field System Consulting Group in Engineering at DuPont, in Houston, Texas. His specialty is the design, operation, and maintenance of electric power distribution systems and large motor installations. He has 20 years E , I T , w of consulting experience with DuPont. Mr. Thornton received his B.S. degree Figure 1. Block Representation of Energy Conversion for Motors. (Electrical Engineering, 1978) from Virginia Polytechnic Institute and State University. The coupling magnetic field is key to the operation of electrical He is a registered Professional Engineer in the State of Texas. apparatus such as induction motors. The fundamental laws associated with the relationship between electricity and magnetism were derived from experiments conducted by several key scientists J. Kirk Armintor is a Senior Account in the 1800s. Sales Engineer in the Rockwell Automation Houston District Office, in The Woodlands, Basic Design and Theory of Operation Texas. He has 32 years’ experience with The alternating current (AC) induction motor is one of the most motor applications in the petroleum, rugged and most widely used machines in industry. There are two chemical, paper, and pipeline industries. major components of an AC induction motor. The stationary or He has authored technical papers on motor static component is the stator. The rotating component is the rotor. -
Chapter 3 Motion in Two and Three Dimensions
Chapter 3 Motion in Two and Three Dimensions 3.1 The Important Stuff 3.1.1 Position In three dimensions, the location of a particle is specified by its location vector, r: r = xi + yj + zk (3.1) If during a time interval ∆t the position vector of the particle changes from r1 to r2, the displacement ∆r for that time interval is ∆r = r1 − r2 (3.2) = (x2 − x1)i +(y2 − y1)j +(z2 − z1)k (3.3) 3.1.2 Velocity If a particle moves through a displacement ∆r in a time interval ∆t then its average velocity for that interval is ∆r ∆x ∆y ∆z v = = i + j + k (3.4) ∆t ∆t ∆t ∆t As before, a more interesting quantity is the instantaneous velocity v, which is the limit of the average velocity when we shrink the time interval ∆t to zero. It is the time derivative of the position vector r: dr v = (3.5) dt d = (xi + yj + zk) (3.6) dt dx dy dz = i + j + k (3.7) dt dt dt can be written: v = vxi + vyj + vzk (3.8) 51 52 CHAPTER 3. MOTION IN TWO AND THREE DIMENSIONS where dx dy dz v = v = v = (3.9) x dt y dt z dt The instantaneous velocity v of a particle is always tangent to the path of the particle. 3.1.3 Acceleration If a particle’s velocity changes by ∆v in a time period ∆t, the average acceleration a for that period is ∆v ∆v ∆v ∆v a = = x i + y j + z k (3.10) ∆t ∆t ∆t ∆t but a much more interesting quantity is the result of shrinking the period ∆t to zero, which gives us the instantaneous acceleration, a. -
Abstract Controlling Ac Motor Using Arduino
ABSTRACT CONTROLLING AC MOTOR USING ARDUINO MICROCONTROLLER Nithesh Reddy Nannuri, M.S. Department of Electrical Engineering Northern Illinois University, 2014 Donald S Zinger, Director Space vector modulation (SVM) is a technique used for generating alternating current waveforms to control pulse width modulation signals (PWM). It provides better results of PWM signals compared to other techniques. CORDIC algorithm calculates hyperbolic and trigonometric functions of sine, cosine, magnitude and phase using bit shift, addition and multiplication operations. This thesis implements SVM with Arduino microcontroller using CORDIC algorithm. This algorithm is used to calculate the PWM timing signals which are used to control the motor. Comparison of the time taken to calculate sinusoidal signal using Arduino and CORDIC algorithm was also done. NORTHERN ILLINOIS UNIVERSITY DEKALB, ILLINOIS DECEMBER 2014 CONTROLLING AC MOTOR USING ARDUINO MICROCONTROLLER BY NITHESH REDDY NANNURI ©2014 Nithesh Reddy Nannuri A THESIS SUBMITTED TO THE GRADUATE SCHOOL IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE MASTER OF SCIENCE DEPARTMENT OF ELECTRICAL ENGINEERING Thesis Director: Dr. Donald S Zinger ACKNOWLEDGEMENTS I would like to express my sincere gratitude to Dr. Donald S. Zinger for his continuous support and guidance in this thesis work as well as throughout my graduate study. I would like to thank Dr. Martin Kocanda and Dr. Peng-Yung Woo for serving as members of my thesis committee. I would like to thank my family for their unconditional love, continuous support, enduring patience and inspiring words. Finally, I would like to thank my friends and everyone who has directly or indirectly helped me for their cooperation in completing the thesis. -
Electric Motors
SPECIFICATION GUIDE ELECTRIC MOTORS Motors | Automation | Energy | Transmission & Distribution | Coatings www.weg.net Specification of Electric Motors WEG, which began in 1961 as a small factory of electric motors, has become a leading global supplier of electronic products for different segments. The search for excellence has resulted in the diversification of the business, adding to the electric motors products which provide from power generation to more efficient means of use. This diversification has been a solid foundation for the growth of the company which, for offering more complete solutions, currently serves its customers in a dedicated manner. Even after more than 50 years of history and continued growth, electric motors remain one of WEG’s main products. Aligned with the market, WEG develops its portfolio of products always thinking about the special features of each application. In order to provide the basis for the success of WEG Motors, this simple and objective guide was created to help those who buy, sell and work with such equipment. It brings important information for the operation of various types of motors. Enjoy your reading. Specification of Electric Motors 3 www.weg.net Table of Contents 1. Fundamental Concepts ......................................6 4. Acceleration Characteristics ..........................25 1.1 Electric Motors ...................................................6 4.1 Torque ..............................................................25 1.2 Basic Concepts ..................................................7 -
Exploring Robotics Joel Kammet Supplemental Notes on Gear Ratios
CORC 3303 – Exploring Robotics Joel Kammet Supplemental notes on gear ratios, torque and speed Vocabulary SI (Système International d'Unités) – the metric system force torque axis moment arm acceleration gear ratio newton – Si unit of force meter – SI unit of distance newton-meter – SI unit of torque Torque Torque is a measure of the tendency of a force to rotate an object about some axis. A torque is meaningful only in relation to a particular axis, so we speak of the torque about the motor shaft, the torque about the axle, and so on. In order to produce torque, the force must act at some distance from the axis or pivot point. For example, a force applied at the end of a wrench handle to turn a nut around a screw located in the jaw at the other end of the wrench produces a torque about the screw. Similarly, a force applied at the circumference of a gear attached to an axle produces a torque about the axle. The perpendicular distance d from the line of force to the axis is called the moment arm. In the following diagram, the circle represents a gear of radius d. The dot in the center represents the axle (A). A force F is applied at the edge of the gear, tangentially. F d A Diagram 1 In this example, the radius of the gear is the moment arm. The force is acting along a tangent to the gear, so it is perpendicular to the radius. The amount of torque at A about the gear axle is defined as = F×d 1 We use the Greek letter Tau ( ) to represent torque. -
Improvement of Electromagnetic Railgun Barrel Performance and Lifetime By
IMPROVEMENT OF ELECTROMAGNETIC RAILGUN BARREL PERFORMANCE AND LIFETIME BY METHOD OF INTERFACES AND AUGMENTED PROJECTILES A Thesis Presented to the Faculty of California Polytechnic State University San Luis Obispo In Partial Fulfillment of the Requirements for the Degree Master of Science in Aerospace Engineering by Aleksey Pavlov June 2013 c 2013 Aleksey Pavlov ALL RIGHTS RESERVED ii COMMITTEE MEMBERSHIP TITLE: Improvement of Electromagnetic Rail- gun Barrel Performance and Lifetime by Method of Interfaces and Augmented Pro- jectiles AUTHOR: Aleksey Pavlov DATE SUBMITTED: June 2013 COMMITTEE CHAIR: Kira Abercromby, Ph.D., Associate Professor, Aerospace Engineering COMMITTEE MEMBER: Eric Mehiel, Ph.D., Associate Professor, Aerospace Engineering COMMITTEE MEMBER: Vladimir Prodanov, Ph.D., Assistant Professor, Electrical Engineering COMMITTEE MEMBER: Thomas Guttierez, Ph.D., Associate Professor, Physics iii Abstract Improvement of Electromagnetic Railgun Barrel Performance and Lifetime by Method of Interfaces and Augmented Projectiles Aleksey Pavlov Several methods of increasing railgun barrel performance and lifetime are investigated. These include two different barrel-projectile interface coatings: a solid graphite coating and a liquid eutectic indium-gallium alloy coating. These coatings are characterized and their usability in a railgun application is evaluated. A new type of projectile, in which the electrical conductivity varies as a function of position in order to condition current flow, is proposed and simulated with FEA software. The graphite coating was found to measurably reduce the forces of friction inside the bore but was so thin that it did not improve contact. The added contact resistance of the graphite was measured and gauged to not be problematic on larger scale railguns. The liquid metal was found to greatly improve contact and not introduce extra resistance but its hazardous nature and tremendous cost detracted from its usability. -
Rotation: Moment of Inertia and Torque
Rotation: Moment of Inertia and Torque Every time we push a door open or tighten a bolt using a wrench, we apply a force that results in a rotational motion about a fixed axis. Through experience we learn that where the force is applied and how the force is applied is just as important as how much force is applied when we want to make something rotate. This tutorial discusses the dynamics of an object rotating about a fixed axis and introduces the concepts of torque and moment of inertia. These concepts allows us to get a better understanding of why pushing a door towards its hinges is not very a very effective way to make it open, why using a longer wrench makes it easier to loosen a tight bolt, etc. This module begins by looking at the kinetic energy of rotation and by defining a quantity known as the moment of inertia which is the rotational analog of mass. Then it proceeds to discuss the quantity called torque which is the rotational analog of force and is the physical quantity that is required to changed an object's state of rotational motion. Moment of Inertia Kinetic Energy of Rotation Consider a rigid object rotating about a fixed axis at a certain angular velocity. Since every particle in the object is moving, every particle has kinetic energy. To find the total kinetic energy related to the rotation of the body, the sum of the kinetic energy of every particle due to the rotational motion is taken. The total kinetic energy can be expressed as .. -
Electrical Machines-II 2015-16(ODD)
A Course Material on Electrical Machines-II 2015-16(ODD) By Mrs. M.Latha Assistant Professor DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING SASURIE COLLEGE OF ENGINEERING VIJAYAMANGALAM – 638 056 QUALITY CERTIFICATE This is to certify that the e-course material Subject Code : EE6504 Subject : Electrical Machines -II Class : III YEAR EEE Being prepared by me and it meets the knowledge requirement of the university curriculum. Signature of the Author Name: M.Latha Designation: AP This is to certify that the course material being prepared by Mrs.M.Latha is of adequate quality. She has referred more than five books among them minimum one is from aboard author. Signature of HD Name: SEAL Syllabus EE6504 Electrical Machines -II UNIT I SYNCHRONOUS GENERATOR Constructional details – Types of rotors –winding factors- emf equation – Synchronous reactance –Armature reaction – Phasor diagrams of non salient pole synchronous generator connected to infinite bus--Synchronizing and parallel operation – Synchronizing torque -Change of excitation and mechanical input- Voltage regulation – EMF, MMF, ZPF and A.S.A methods – steady state power angle characteristics– Two reaction theory –slip test -short circuit transients - Capability Curves UNIT II SYNCHRONOUS MOTOR Principle of operation – Torque equation – Operation on infinite bus bars - V and Inverted V curves – Power input and power developed equations – Starting methods – Current loci for constant power input, constant excitation and constant power developed-Hunting – natural frequency of oscillations – damper windings- synchronous condenser. UNIT III THREE PHASE INDUCTION MOTOR Constructional details – Types of rotors –- Principle of operation – Slip –cogging and crawling- Equivalent circuit – Torque-Slip characteristics - Condition for maximum torque – Losses and efficiency – Load test - No load and blocked rotor tests - Circle diagram – Separation of losses – Double cage induction motors –Induction generators – Synchronous induction motor.