Download or read book Fault Tolerant Homopolar Magnetic Bearings written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic suspensions (MS) satisfy the long life and low loss conditions demanded by satellite and ISS based flywheels used for Energy Storage and Attitude Control (ACESE) service. This paper summarizes the development of a novel MS that improves reliability via fault tolerant operation. Specifically, flux coupling between poles of a homopolar magnetic bearing is shown to deliver desired forces even after termination of coil currents to a subset of failed poles . Linear, coordinate decoupled force-voltage relations are also maintained before and after failure by bias linearization. Current distribution matrices (CDM) which adjust the currents and fluxes following a pole set failure are determined for many faulted pole combinations. The CDM s and the system responses are obtained utilizing 1D magnetic circuit models with fringe and leakage factors derived from detailed, 3D, finite element field models. Reliability results are presented vs. detection/correction delay time and individual power amplifier reliability for 4, 6, and 7 pole configurations. Reliability is shown for two success criteria, i.e. (a) no catcher bearing contact following pole failures and (b) re-levitation off of the catcher bearings following pole failures. An advantage of the method presented over other redundant operation approaches is a significantly reduced requirement for backup hardware such as additional actuators or power amplifiers. Li, Ming-Hsiu and Palazzolo, Alan and Kenny, Andrew and Provenza, Andrew and Beach, Raymond and Kascak, Albert Glenn Research Center NASA/TM-2003-212592, E-14149, NAS 1.15:212592, AIAA Paper 2003-6110
Download or read book Fault Tolerant Homopolar Magnetic Bearings written by and published by . This book was released on 2003 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fault Tolerant Control of Homopolar Magnetic Bearings and Circular Sensor Arrays written by Ming-Hsiu Li and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fault tolerant control can accommodate the component faults in a control system such as sensors, actuators, plants, etc. This dissertation presents two fault tolerant control schemes to accommodate the failures of power amplifiers and sensors in a magnetic suspension system. The homopolar magnetic bearings are biased by permanent magnets to reduce the energy consumption. One control scheme is to adjust system parameters by swapping current distribution matrices for magnetic bearings and weighting gain matrices for sensor arrays, but maintain the MIMO-based control law invariant before and after the faults. Current distribution matrices are evaluated based on the set of poles (power amplifier plus coil) that have failed and the requirements for uncoupled force/voltage control, linearity, and specified force/voltage gains to be unaffected by the failure. Weighting gain matrices are evaluated based on the set of sensors that have failed and the requirements for uncoupling x1 and x2 sensing, runout reduction, and voltage/displacement gains to be unaffected by the failure. The other control scheme is to adjust the feedback gains on-line or off-line, but the current distribution matrices are invariant before and after the faults. Simulation results have demonstrated the fault tolerant operation by these two control schemes.
Download or read book High Temperature Permanent Magnet Biased Magnetic Bearings written by Varun R. Gandhi and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Electron Energy Corporation (EEC) along with the National Aeronautics and Space Administration (NASA) is researching magnetic bearings. The purpose of this research was to design and develop a high-temperature (1000°F) magnetic bearing system using High Temperature Permanent Magnets (HTPM), developed by the EEC. The entire system consisted of two radial bearings, one thrust bearing, one motor and 2 sets of catcher bearings. This high temperature magnetic bearing system will be used in high performance, high speed and high temperature applications like space vehicles, jet engines and deep sea equipment. The bearing system had a target design to carry a load equal to 500 lb-f (2225N). Another objective was to design and build a test rig fixture to measure the load capacity of the designed high temperature radial magnetic bearing (HTRMB) called Radial Bearing Force Test Rig (RBFTR). A novel feature of this high temperature magnetic bearing is its homopolar construction which incorporates state of the art high temperature, 1000°F, permanent magnets. A second feature is its fault tolerance capability which provides the desired control forces even if half the coils have failed. The permanent magnet bias of the radial magnetic bearing reduces the amount of current required for magnetic bearing operation. This reduces the power loss due to the coil current resistance and also increases the system efficiency because magnetic field of the HTPM is used to take up the major portion of the static load on the bearing. The bias flux of the homopolar radial bearing is produced by the EEC HTPM to reduce the related ohmic losses of an electromagnetic circuit significantly. An experimental procedure was developed using the Radial Bearing Force Test Rig (RBTFR) to measure actual load capacity of the designed bearing at the test rig. All the results obtained from the experiment were compiled and analyzed to determine the relation between bearing force, applied current and temperature.
Download or read book Magnetic Bearings written by Gerhard Schweitzer and published by Springer Science & Business Media. This book was released on 2009-06-10 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compiling the expertise of nine pioneers of the field, Magnetic Bearings - Theory, Design, and Application to Rotating Machinery offers an encyclopedic study of this rapidly emerging field with a balanced blend of commercial and academic perspectives. Every element of the technology is examined in detail, beginning at the component level and proceeding through a thorough exposition of the design and performance of these systems. The book is organized in a logical fashion, starting with an overview of the technology and a survey of the range of applications. A background chapter then explains the central concepts of active magnetic bearings while avoiding a morass of technical details. From here, the reader continues to a meticulous, state-of-the-art exposition of the component technologies and the manner in which they are assembled to form the AMB/rotor system. These system models and performance objectives are then tied together through extensive discussions of control methods for both rigid and flexible rotors, including consideration of the problem of system dynamics identification. Supporting this, the issues of system reliability and fault management are discussed from several useful and complementary perspectives. At the end of the book, numerous special concepts and systems, including micro-scale bearings, self-bearing motors, and self-sensing bearings, are put forth as promising directions for new research and development. Newcomers to the field will find the material highly accessible while veteran practitioners will be impressed by the level of technical detail that emerges from a combination of sophisticated analysis and insights gleaned from many collective years of practical experience. An exhaustive, self-contained text on active magnetic bearing technology, this book should be a core reference for anyone seeking to understand or develop systems using magnetic bearings.
Download or read book Magnetic Bearings Magnetic Drives and Dry Gas Seals Conference written by and published by CRC Press. This book was released on 1997-08-12 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: A pre-conference collection of 30 papers that contribute to the event's purpose of promoting the use of magnetic bearings in industrial applications. They cover applications in pumps, turbines, machining, textile spindles, compressors, and fans; auxiliary bearings; magnetic suspension; controls; mod
Download or read book Fault tolerant Control of Heteropolar Magnetic Bearings written by Uhn Joo Na and published by . This book was released on 1999 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Bearings and Bearingless Drives written by Akira Chiba and published by Elsevier. This book was released on 2005-05-20 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of bearingless drives is emerging as an important technique in the areas of high-speed machinery and motion-control, and this book aims to provide a thorough grounding in the principles behind this cutting-edge technology. Basic principles are described in detail with practical examples to aid understanding, and the different types of bearingless drives are introduced, along with coverage of test machines and applications. Aimed at practising electrical and mechanical engineers and advanced students, Magnetic Bearings and Bearingless Drives provides an essential guide to an area of engineering previously only fully covered by large numbers of academic papers. · Unique and comprehensive coverage of a cutting-edge subject for electrical and mechanical engineers · A reference text and survey for designers, manufacturers and users of high-speed motors, generators and electrical drive systems · Examines the basic principles behind magnetic bearings, with key technologies and applications illustrated through examples and case studies
Download or read book High Speed Operation and Testing of a Fault Tolerant Magnetic Bearing written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-24 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research activities undertaken to upgrade the fault-tolerant facility, continue testing high-speed fault-tolerant operation, and assist in the commission of the high temperature (1000 degrees F) thrust magnetic bearing as described. The fault-tolerant magnetic bearing test facility was upgraded to operate to 40,000 RPM. The necessary upgrades included new state-of-the art position sensors with high frequency modulation and new power edge filtering of amplifier outputs. A comparison study of the new sensors and the previous system was done as well as a noise assessment of the sensor-to-controller signals. Also a comparison study of power edge filtering for amplifier-to-actuator signals was done; this information is valuable for all position sensing and motor actuation applications. After these facility upgrades were completed, the rig is believed to have capabilities for 40,000 RPM operation, though this has yet to be demonstrated. Other upgrades included verification and upgrading of safety shielding, and upgrading control algorithms. The rig will now also be used to demonstrate motoring capabilities and control algorithms are in the process of being created. Recently an extreme temperature thrust magnetic bearing was designed from the ground up. The thrust bearing was designed to fit within the existing high temperature facility. The retrofit began near the end of the summer, 04, and continues currently. Contract staff authored a NASA-TM entitled "An Overview of Magnetic Bearing Technology for Gas Turbine Engines", containing a compilation of bearing data as it pertains to operation in the regime of the gas turbine engine and a presentation of how magnetic bearings can become a viable candidate for use in future engine technology. DeWitt, Kenneth and Clark, Daniel Glenn Research Center
Download or read book Fault Tolerant Control of Rotor magnetic Bearing Systems written by Matthew Owen Thomas Cole and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Bearings written by G. Schweitzer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Bearings are bearings where the suspension forces are generated magnetically without any contact. The advantages to modern machinery are obvious: no mechanical wear, no lubrication, potential for high rotor speed, accuracy, and high dynamic performance, new constructional solutions to a classical problem in machine dynamics. The realization of such bearings is in rapid progress. Examples for application areas are turbomachinery, centrifuges, vacuum techniques, machine tool spindles, chemical industry, medical devices, robotics, high speed drives, spacecraft equipment, con tactless actuators, vibration isolation. The Symposium is demonstrating the current state of the art in this developing field of mechatronics, showing actual research efforts, reporting on applications in the various areas, and discussing open questions. The main purpose of the Symposium has been to establish a common information basis for people working on magnetic bearings. It will point to promising areas, and it will help to facilitate decisions on research and development projects, and on investments for applications.
Download or read book Les Etrennes de la Saint Jean written by and published by . This book was released on 1791 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Permanent Magnet Biased Homopolar Magnetic Bearing Actuator written by Mohammad Ahsan Hossain and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The EEC (Electron Energy Corporation) in conjunction with the National Aeronautics and Space Administration is researching the magnetic bearings for an alternative to conventional journal or ball bearings. The purpose of this research was to design and develop a high-temperature (1000°F) hybrid Magnetic Bearing using High Temperature Permanent Magnets (HTPM), developed by the EEC for high performance jet engines at high speeds that supply loads of 500 lbf. Another objective is to design and build a test rig fixture to measure the load capacity of the designed bearing. The permanent magnet bias of the Homopolar radial magnetic bearing reduces the amount of current required for magnetic bearing operation. This reduces the power loss due to the coil current resistance and improves the system efficiency because the magnetic field of the HTPM can suspend the major portion of the static load on bearing. A high temperature radial magnetic bearing was designed via an iterative search employing 3D finite element based electromagnetic field simulations. The bearing was designed to produce 500 lbf of force at 1000°F and the design weight is 48 lbs. The bias flux of the Homopolar radial bearing is produced by EEC HTPM to reduce the related ohmic losses of an electromagnetic circuit significantly. An experimental procedure was developed to measure actual load capacity of the designed bearing at the test rig. All the results obtained from the experiment were compiled and analyzed to determine the relation between bearing force, applied current and temperature.
Download or read book Feedback Control of a Permanent Magnet Biased Homopolar Magnetic Bearing System written by Vishal Ashok Wadhvani and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic bearings are increasingly being used in a wide variety of applications in the industry such as compressors, turbines, motors, generators etc. Also, there are different types available depending upon their construction. The research presented here investigates a high temperature permanent magnet biased magnetic bearing system which is jointly being researched by National Aeronautics and Space Administration (NASA) and Electron Energy Corporation (EEC). The purpose of this research was to develop a permanent magnet biased magnetic bearing system using high temperature (HT) permanent magnets (PM) developed by EEC. This system was designed for high performance, high temperature (1000F) and high speed applications. The entire system consisted of two radial bearings, two catcher bearings, one axial thrust bearing and a motor. The central rotor shaft is powered by a high temperature permanent magnet motor to be able to run at the designed conditions of 20,000 rpm. This thesis documents the design of a feedback control law that stabilizes this HTPM biased AMB levitated system and summarizes efforts to build a test rig for the HT tests of the machine. A decentralized PD control law is used to achieve successful levitation. An existing PD analog controller with single input single output (SISO) control law for each axis (previously used for a flywheel test rig) is used as a feedback controller for this HTPM magnetic bearing system. Modeling and simulation of the resulting closed loop system is done in Matlab to test for stability and an iterative approach leads to optimum values of proportional and derivative gain pairs. The notch filter locations are also determined through this closed loop iterative simulation.
Download or read book Magnetic Bearings for Assist Devices written by Stephen Day and published by Momentum Press. This book was released on 2015-12-16 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces magnetic bearings--mechatronic devices that produce contact-free electromagnetic force to support a load, such as a moving train or a spinning rotor. Compared to traditional bearings, magnetic bearings offer several advantages: no friction, low heat generation, no required lubrication, quiet operation, and fast and stable rotation. For these reasons, magnetic bearings have been used in rotary ventricular assist devices (VADs) to increase design life, reduce or eliminate material wear and bearing maintenance, as well as to increase biocompatibility by eliminating high fluid stresses and heat generation, both of which are associated with hemolysis, platelet activation and aggregation, and thrombus growth. The book covers the principles of these bearings, how they are used in integrated control and electronics systems, and useful information on several major brands of current assist devices.
Download or read book Fault tolerant magnetic bearings ASME 98 GT 377 written by Eric H. Maslen and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Stockholm, Sweden, Jun 2-5, 1998.
Download or read book Proceedings of the Intersociety Energy Conversion Engineering Conference written by and published by . This book was released on 2002 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:
