How to Select Carbon Brushes for Motors and Generators
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Transient Analysis of Three-Phase Wound Rotor (Slip-Ring) Induction Motor Under Operating Condition
International Journal of Recent Engineering Research and Development (IJRERD) ISSN: 2455-8761 www.ijrerd.com || Volume 02 – Issue 07 || July 2017 || PP. 19-32 Transient Analysis of Three-Phase Wound Rotor (Slip-Ring) Induction Motor under Operating Condition Obute K.C.1, Enemuoh F.O.1 1 – Department of Electrical Engineering Nnamdi Azikiwe University Awka, Anambra State Nigeria Corresponding Author - Obute Kingsley Chibueze Department of Electrical Engineering Nnamdi Azikiwe University Awka, Anambra State Nigeria Abstract: This work investigates the transient behaviours of a three phase wound rotor type induction motor, running on load. When starting a motor under load condition becomes paramount, obviously a wound rotor (slip ring) induction becomes the best choice of A.C. motor. This is because maximum torque at starting can be achieved by adding external resistance to the rotor circuit through slip-rings. Normally a face-plate type starter is used, and as the resistance is gradually reduced, the motor characteristics at each stage changes from the other (John Bird 2010). Hence, the three phase wound rotor (slip ring) induction motor competes favourably with the squirrel cage induction motor counterpart as the most widely used three-phase induction motor for industrial applications. The world-wide popularity and availability of this motor type has attracted a deep – look and in-depth research including its transient behavior under plugging (operating) condition. This paper unveils, through mathematical modeling, followed by dynamic simulation, the transient performance of this peculiar machine, analyzed based on Park’s transformation technique. That is with direct-quadrature-zero (d-q-o) axis based modeling in stationary reference frame. -
Electrical Machines
1 Electrical Machines 1. The left hand rule is applicable to (a) generator ( b) motor (c) transformer ( d) ( a) and ( b) both (e) ( a) or ( b) 2. The eddy current losses in the transformer will be reduced if (a) the laminations are thick (b) number of turns in the primary winding is reduced (c) the number of turns in the secondary winding is reduced (d) the laminations are thin 3. The speed of d.c. series motor at no load is (a) zero ( b) 1500 r.p.m. (c) infinity ( d) 3000 r.p.m. (e) none of the above 4. A sinusoidal voltage of frequency 1 Hz is applied to the field of d.c. generator. The armature voltage will be (a) 1 Hz square wave ( b) 1 Hz sinusoidal voltage (c) d.c. voltage ( d) none of the above 5. The function of the commutator in a d.c. machine is (a) to change alternating current to a direct current (b) to improve commutation (c) for easy control (d) to change alternating voltage to direct voltage 6. The phase sequence of voltage generated in the alternator can be reversed by reversing its field current. (a) true ( b) false 7. The rotation of three phase induction motor can be reversed by interchanging any two of the supply phases. (a) true ( b) false 2 ELECTRICAL ENGINEERING 8. The starting torque of the three phase induction motor can be increased by (a) increasing the rotor reactance (b) increasing the rotor resistance (c) increasing the stator resistance (d) none of the above 9. -
NNNNN May 19, 1970 A
May 19, 1970 A. D. APPLETON 3,513,340 HOMOPOLAR ELLCTRIC MACHINES Filed Jan. 6, 1967 2 Sheets-Sheet l -uo Lo NNNNN May 19, 1970 A. D. APPLETON HOMOPOLAR ELECTRIC MACHINES 3,513,340 Filed Jan. 6, 1967 2 Sheets-Sheet 2 222a1a1a2.1274.1444/4/14/a/ 244. A. ZZ 3,513,340 United States Patent Office Patented May 19, 1970 2 3,513,340 FIG. 1 shows diagrammatically a homopolar electrical HOMOPOLAR ELECTRIC MACHINES machine in accordance with the invention for use as a low Anthony Derek Appleton, Newcastle upon Tyne, Eng speed motor, land, assignor to International Research & Develop FIG. 2 is a longitudinal section of a typical machine of Company Limited, Newcastle upon Tyne, Eng the general form illustrated in FIG. 1, and FIG. 3 is a Filed Jan. 6, 1967, Ser. No. 607,784 detail of FIG. 2 on an enlarged scale. Claims priority, application Great Britain, Jan. 12, 1966, The homopolar machine shown in FIG. 1 comprises 1,530/66 two rotors 1 and 2. Int. Cl. H02k 31/00, 47/14 Each rotor is in the from of a disc of electrically con U.S. C. 310-13 10 Claims ducting material Such as copper. The copper discs may O each be mounted on a supporting disc of non-electrically conducting material. ABSTRACT OF THE DISCLOSURE Each rotor rotates within a magnetic field common to A homopolar machine is disclosed having two rotors both rotors and provided by a single superconducting coil in a common magnetic field, preferably provided by a 3, which surrounds the rotors. -
Brushes for Aircraft Applications
Brushes for Aircraft Applications Bob Nuckolls AeroElectric Connection April 1993 Updated August 2003 Several times a year I receive a call or letter asking where one be 1000 hours or more of continuous motor operation! We obtains "aircraft" grade brushes for an alternator or generator. were hard pressed to demonstrate more than 600 hours from One of my readers called recently to say he had been verbally any grade of brush. This little motor runs at 22,000 rpm! There keel-hauled by an engineer with an alternator manufacturing were simply no brush products available that would last 1000 company. The reader had confessed to considering a plain hours at those commutator surface speeds. vanilla brush for use in the alternator on his RV-4. The program was nearly scuttled when project managers There's a lot of "hangar mythology" about what constitutes became fixated upon reaching the 1000-hour goal. We aircraft ratings in components. We all know that much of what researched our service records for the same motor supplied in is deemed "aircraft" today are the same products certified onto other forms for over 10 years. airplanes 30-50 years ago. Many developers and suppliers consider aviation a "dying" market; few are interested in Clutches and brakes turned out to be the #1 service problem. researching and qualifying new products. However, Brake problems occurred at 300 to 500 flight hours, not motor automotive markets continue to advance in every technology. operating hours. Given that trim operations might run a pitch It is sad to note that many products found on cars today far trim actuator perhaps 3 minutes total per flight cycle, 1000 exceed the capabilities and quality of similar hardware found hours of flight on a Lear might put less than 50 hours on certified airplanes. -
Electricity’ Contribute to the Second Industrial Revolution (I): the Power Engines
Delft University of Technology How did the General Purpose Technology ’Electricity’ contribute to the Second Industrial Revolution (I): The Power Engines. van der Kooij, Bauke Publication date 2016 Document Version Final published version Citation (APA) van der Kooij, B. (2016). How did the General Purpose Technology ’Electricity’ contribute to the Second Industrial Revolution (I): The Power Engines. Important note To cite this publication, please use the final published version (if applicable). Please check the document version above. Copyright Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policy Please contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim. This work is downloaded from Delft University of Technology. For technical reasons the number of authors shown on this cover page is limited to a maximum of 10. How did the General Purpose Technology ’Electricity’ contribute to the Second Industrial Revolution (I): The Power Engines. B.J.G.van der Kooij Guest at the University of Technology, Delft, Netherlands Jaffalaan 5, 2628 BX, Delft, the Netherlands Abstract The concept of the General Purpose Technology (GPT) of the late 1990s is a culmination of many evolutionairy views in innovation-thinking. By definition the GPT considers the technical, social, and economic effects of meta-technologies like steam-technology and electric technology. -
Slip Ring Rotor - Vertical
Motors I Automation I Energy I Transmission & Distribution I Coatings Low and high voltage three phase induction motors M line - Slip ring rotor - Vertical Installation, Operation and Maintenance Manual Installation, Operation and Maintenance Manual Document Number: 11734748 Models: MAA, MAP, MAD, MAT, MAV, MAF, MAR, MAI, MAW and MAL Language: English Revision: 9 August 2018 Dear Customer, Thank you for purchasing a WEG motor. Our products are developed with the highest standards of quality and efficiency which ensures outstanding performance. Since electric motors play a major role in the comfort and well-being of mankind, it must be identified and treated as a driving machine with characteristics that involve specific care, such as proper storage, installation and maintenance All efforts have been made to ensure that the information contained in this manual is faithful to the configurations and applications of the motor. Therefore, we recommend that you read this manual carefully before proceeding with the installation, operation or maintenance of the motor in order to ensure safe and reliable operation of your equipment and facility. If you need any further information, please contact WEG. Always keep this manual close to the motor, so that it can be consulted whenever necessary. ATTENTION 1. It is imperative to follow the procedures contained in this manual for the warranty to be valid; 2. The motor installation, operation and maintenance procedures must be performed only by qualified personnel. NOTES 1. The total or partial reproduction of information supplied in this manual is authorized, provided that reference is made to its source. If this manual is lost, an electronic PDF file is available at www.weg.net or another printed copy may be requested. -
ELECTRICAL SCIENCE Module 10 AC Generators
DOE Fundamentals ELECTRICAL SCIENCE Module 10 AC Generators Electrical Science AC Generators TABLE OF CONTENTS Table of Co nte nts TABLE OF CONTENTS ................................................................................................... i LIST OF FIGURES ...........................................................................................................ii LIST OF TABLES ............................................................................................................ iii REFERENCES ................................................................................................................iv OBJECTIVES .................................................................................................................. v AC GENERATOR COMPONENTS ................................................................................. 1 Field ............................................................................................................................. 1 Armature ...................................................................................................................... 1 Prime Mover ................................................................................................................ 1 Rotor ............................................................................................................................ 1 Stator ........................................................................................................................... 2 Slip Rings ................................................................................................................... -
Electromagnetic Coil Gun Launcher System
ISSN(Online): 2319-8753 ISSN (Print) : 2347-6710 International Journal of Innovative Research in Science, Engineering and Technology (A High Impact Factor, Monthly, Peer Reviewed Journal) Visit: www.ijirset.com Vol. 8, Issue 3, March 2019 Electromagnetic Coil Gun Launcher System Prof. Yogesh Fatangde1 Swapnil Biradar2, Aniket Bahmne3, Suraj Yadav4, Ajay Yadav5 Department of Mechanical Engineering, RMD Sinhgad Technical Campus, Savitribai Phule Pune University, Pune, Maharashtra, India1 ABSTRACT: In our present time, a study was undertaken to determine if ground based electromagnetic acceleration system could provide a useful reduction in launching cost with current large chemical boosters, while increasing launch safety and reliability. An electromagnetic launcher (EML) system accelerates and launches a projectile by converting electric energy into kinetic energy. An EML system launches projectile by converting electric energy into kinetic energy. There are two types of EML system under development: rail gun and coil gun. A coil gun launches the projectile by magnetic force of electromagnetic coil. A higher velocity needs multiple stages of system, which make coil gun EML system longer. As a result installation cost is very high and it required large installation site for EML. So, we present coil gun EML system with new structure and arrangement for multiple electromagnetic coils to reduce the length of system KEYWORDS: EML, coil gun, Electromagnetic launcher, suck back effect I. INTRODUCTION In chemical launcher systems such as firearms and satellite launchers, chemical explosive energy is converted into mechanical dynamic energy. The system must be redesigned and remanufactured if the target velocity of the projectile is changed. In addition, such systems are not eco-friendly. -
Construction Set Curriculum
Construction Set Curriculum Grades 8-12 Student Edition Center for Mathematics Science and Technology Center for Renewable Energy Illinois State University Normal, Illinois 1 Construction Set Curriculum Grades 8 - 12 Nearly everything done by humans re- quires some type of energy. Of course, manufacturing, transportation, and con- struction require energy, but also the “little things,” like heating your food and charging your cell phone. Energy allows things to be done. Imagine the changes necessary if gasoline was suddenly unavailable for your car, or electricity was shut off at your school. Modern society could not function without energy. Nearly all work was accomplished entirely by muscle power until relatively recent times. The domestication of animals helped to make work easier and more efficient, but both humans and animals have limited power and get tired easily. Inventors have always been looking for ways to produce power that is reliable and inexpensive. At the end of the Roman era, by about 200 B.C., Europeans were using waterwheels to crush grain, saw wood, and do many more tasks. 1200 years later in 1000 A.D., the Dutch had harnessed the power of wind to do many of the same tasks as well as pump water out of manmade basins to expose land. https://www.google.com/imgres?imgurl=https%3A%2F%2Fi.redd.it%2F7en51y8osrlz.jpg&imgrefurl=https%3A%2F%2Fwww.reddit.com%2Fr%2Fancientrome% 2Fcomments%2F6zzw4v%2Fthe_norias_of_hama_tech_referenced_in_painting% 2F&tbnid=cFD679meUV8DfM&vet=12ahUKEwjpnKP9r7vnAhVBYa0KHWLlCCAQMygJegQIARBR..i&docid=Yg5zCQjBvV2lmM&w=972&h=648&itg=1&q=roman% 20water%20wheel&hl=en&ved=2ahUKEwjpnKP9r7vnAhVBYa0KHWLlCCAQMygJegQIARBR 2 Your Horsepower When James Watt first invented the steam engine, he was naturally asked how much power it pro- duced. -
Motor Actuators Basics
Motor Actuators Basics - 1 - Note: All specifications and other information are not guaranteed and are subject to change without notice. Prior to any new usage of JE motor actuators it is recommended to contact Johnson Electric. All information below and content of links are subject to the disclaimer of the Johnson Electric website - 2 - Contents Overview ....................................................................................................................................................................... 4 Classification ............................................................................................................................................................. 5 DC Motors ................................................................................................................................................................. 6 Universal Motors ....................................................................................................................................................... 7 BLDC Motors ............................................................................................................................................................. 8 Synchronous Motors ................................................................................................................................................. 9 Stepper Motors ........................................................................................................................................................ 10 Shaded -
Brush DC Motors Turning More Advanced
Brush DC Motors wearing process by targeting brush assemblies, brush size, and brush materials. turning More Advanced The traditional method for mounting brushes in DC motor assem- blies has been to solder the brushes onto standard cantilever “Off-the-shelf” brush-commutated DC motors typically springs to enable the required constant contact with the commu- tend to serve as a “starting point,” because virtually every tator. The conventional spring design, however, exhibits inherent application for a motor carries particular design and drawbacks as force levels diminish over time, often resulting in performance criteria to be accommodated. premature motor failure. Motor manufacturers usually address these criteria by This problem can be overcome by housing brushes within a customizing products with components to satisfy the specially designed cartridge and utilizing torsion springs to ensure demands. An end-user thereby gains a motor designed to desired even force over the life of a motor. perform as required and, in the process, others ultimately may benefit if and when a custom component becomes The cartridge brush assembly fits into the motor base and “standard.” Many innovations in motor technology, in fact, consists of a two-piece, high-temperature plastic snap-together have originated as specific solutions to specific customer assembly in which each of two brushes is seated securely within its challenges. own specially constructed slot. This cartridge design restricts the brushes to traveling in a track in a desired linear motion. The design further can provide for an ideal Innovations have further been driven by overall marketplace needs. region of pressure for brushes to withstand the detrimental effects As examples, motor manufacturers have been obliged to offer more of mechanical wear. -
Electrical Engineering
ESE-2016 Answer key of (Objective Paper-II) Electrical Engineering solutions Answer Key of Electrical Engg. Objective Paper-II (ESE - 2016) SET - A 1. Compared to the salient-pole Hydroelectric 4. The regulation of a transformer in which ohmic generators, the steam and the gas-turbine have loss is 1% of the output and reactance drop is cylindrical rotors for 5% of the voltage, when operating at 0.8 power factor lagging, is (a) Better air-circulation in the machine (a) 3.8% (b) 4.8% (b) Reducing the eddy-current losses in the rotor (c) 5.2% (d) 5.8% (c) Accommodating larger number of turns in Sol. (a) the field winding 5. In a power transformer, the core loss is 50 W (d) Providing higher mechanical strength at 40 Hz and 100 W at 60 Hz, under the against the centrifugal stress condition of same maximum flux density in both Sol. (d) cases. The core loss at 50 Hz will be 2. Consider the following losses for short circuit (a) 64 W (b) 73 W test on a transformer: (c) 82 W (d) 91 W 1. Copper loss Sol. (b) 2. Copper and iron losses 6. Consider the following advantages of a 3. Eddy current and hysteresis losses distributed winding in a rotating machine: 4. Friction and windage losses 1. Better utilization of core as a number of evenly placed small slots are used Which of the above is/are correct ? 2. Improved waveform as harmonic emf’s are (a) 1 only (b) 2 only reduced (c) 3 only (d) 2, 3 and 4 3.