Schweitzer / Maslen Magnetic Bearings

Theory, Design, and Application to Rotating Machinery
1. Auflage 2009
ISBN: 978-3-642-00497-1
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 535 Seiten

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.

Autoren/Hrsg.

Schweitzer, Gerhard

Maslen, Eric H.

Inhaltsverzeichnis

1;Preface;5
2;Contents;7
3;List of Contributors;9
4;The Authors;11
5;1 Introduction and Survey;16
5.1;1.1 Principles of Magnetic Bearing Function;16
5.2;1.2 The Magnetic Bearing as a Mechatronic Product;19
5.3;1.3 The Magnetic Bearing in Transportation, Physics and Mechanical Engineering;20
5.4;1.4 Classification of Magnetic Bearings;25
5.5;1.5 Characteristics of Active Magnetic Rotor Bearings;30
5.6;1.6 Examples from Research and Industry;32
5.7;References;39
6;2 Principle of Active Magnetic Suspension;42
6.1;2.1 The Magnetic Bearing as a Controlled Suspension;42
6.2;2.2 Closing the Control Loop of a Magnetic Bearing;48
6.3;2.3 Feedback Control Design;66
6.4;2.4 Forced Vibration and Frequency Response;70
6.5;References;82
7;3 Hardware Components;84
7.1;3.1 Bearing Electromagnets;85
7.2;3.2 Permanent Magnet Biased Magnetic Bearings;110
7.3;3.3 Power Ampli.ers;112
7.4;3.4 Sensors;114
7.5;3.5 Concluding Remarks;122
7.6;References;123
8;4 Actuators;125
8.1;4.1 Structure;125
8.2;4.2 Amplifiuers;126
8.3;4.3 Electromagnets;129
8.4;4.4 Actuator assembly;131
8.5;4.3 Electromagnets;129
8.6;4.4 Actuator assembly;131
8.7;4.5 Examples;134
8.8;4.6 Driving Modes and Linearization;138
8.9;4.7 Response Limitations of the Magnetic Actuator;141
8.10;4.8 Measuring System Characteristics;145
8.11;References;147
9;5 Losses in Magnetic Bearings;149
9.1;5.1 Overview;149
9.2;5.2 Iron Losses in the Rotor;152
9.3;5.3 Aerodynamic Losses, Windage Losses;154
9.4;5.4 Determining Rotor Losses;160
9.5;5.5 Measures to Reduce Losses;161
9.6;5.6 Losses in Various Applications;162
9.7;References;164
10;6 Design Criteria and Limiting Characteristics;165
10.1;6.1 Load Capacity;165
10.2;6.2 Controller and Actuator;166
10.3;6.3 Speed;168
10.4;6.4 Size;172
10.5;6.5 High Temperature;172
10.6;6.6 Losses;173
10.7;6.7 Precision;175
10.8;6.8 Smart Machine Concept;175
10.9;6.9 Conclusions;176
10.10;References;177
11;7 Dynamics of the Rigid Rotor;180
11.1;7.1 Introduction;180
11.2;7.2 Inertia Properties;180
11.3;7.3 Natural Vibrations of a Rotor on Elastic Supports;184
11.4;7.4 In.uence of Rotor Speed and Gyroscopic E.ects;189
11.5;7.5 Static and Dynamic Unbalance;193
11.6;7.6 Rotor Excitations and Critical Speeds;195
11.7;References;202
12;8 Control of the Rigid Rotor in AMBs;203
12.1;8.1 The Rotor–Bearing Model;203
12.2;8.2 Feedback Control Design;205
12.3;8.3 Unbalance Control;227
12.4;References;236
13;9 Digital Control;241
13.1;9.1 Digital vs. Analog Control;241
13.2;9.2 Digital Control Hardware and Timing Issues;242
13.3;9.3 Basics of Discrete-Time Control;244
13.4;9.4 Control Design for Discrete-Time Systems;254
13.5;9.5 Implementation Aspects of Digital Control;257
13.6;9.6 Diagnostic Capabilities of Digitally Controlled AMBs;258
13.7;References;261
14;10 Dynamics of Flexible Rotors;263
14.1;10.1 Introduction;263
14.2;10.2 Je.cott Rotor – a Simple Flexible Rotor;264
14.3;10.3 Flexible Rotors with Continuous Mass and Stiffness Distribution;275
14.4;10.4 Equations of Motion Based on the Finite Element Method;279
14.5;10.5 Flexible Rotor with Active Magnetic Bearings;300
14.6;10.6 Reduction of Finite Element Models;304
14.7;10.7 Closing Remarks;307
14.8;References;308
15;11 Identification;310
15.1;11.1 Introduction;310
15.2;11.2 Dynamic Characteristics of Rotating Systems;311
15.3;11.3 Identification of Physical and/or Modal Parameters;312
15.4;11.4 Excitation of a Rotor by means of Magnetic Bearings;316
15.5;11.5 Applications for Identi.cation;318
15.6;11.6 Closing Remarks;328
15.7;References;329
16;12 Control of Flexible Rotors;330
16.1;12.1 Flexibility E.ects;330
16.2;12.2 Model Structure;339
16.3;12.3 Model Elements and Assembly;340
16.4;12.4 Simplest Control: Collocated Local PID;353
16.5;12.5 Performance Assessment;358
16.6;12.6 Non-collocated Local PID Control;363
16.7;12.7 Sensitivity;366
16.8;12.8 Non-collocated Mixed PID Control;372
16.9;12.9 H8 Norm;377
16.10;12.10 H8 Control;378
16.11;12.11 µ.Control;381
16.12;12.12 Asymmetric Example;386
16.13;12.13 Gyroscopics;388
16.14;12.14 Unbalance Control;389
16.15;12.15 Closing Remarks;394
16.16;References;395
17;13 Touch-down Bearings;400
17.1;13.1 A Rotor Contacting its Housing - Survey;401
17.2;13.2 Modeling of Contacts;402
17.3;13.3 Whirl Motion;407
17.4;13.4 Ball Bearings;411
17.5;13.5 Design Considerations;412
17.6;13.6 Conclusions;415
17.7;References;416
18;14 Dynamics and Control Issues for Fault Tolerance;418
18.1;Introduction;418
18.2;14.1 Avoiding Touchdown;418
18.3;14.2 Touch-down Dynamics;423
18.4;References;443
19;15 Self–Sensing Magnetic Bearings;445
19.1;15.1 Concepts;445
19.2;15.2 Motivation;447
19.3;15.3 Control Approaches;448
19.4;15.4 Remaining Technical Challenges;460
19.5;15.5 Conclusions;464
19.6;References;465
20;16 Self–Bearing Motors;470
20.1;16.1 Introduction;470
20.2;16.2 Self-Bearing Motor of the Type P ± 2;472
20.3;16.3 Hybrid Type Self-Bearing Motor;477
20.4;16.4 Lorentz Type Self-Bearing Motor;482
20.5;16.5 Axial Self-Bearing Motor;486
20.6;16.6 Application to Arti.cial Heart Pump;489
20.7;16.7 Concluding remarks;493
20.8;References;493
21;17 Micro Magnetic Bearings;495
21.1;17.1 Introduction to micro magnetic actuators and their down-scaling;495
21.2;17.2 Classification of magnetic bearing types;501
21.3;17.3 Diamagnetic rotor bearings;503
21.4;17.4 Active Magnetic Micro Bearings;506
21.5;17.5 A microbearing for 3 million rpm;507
21.6;17.6 Conclusions;510
21.7;References;511
22;18 Safety and Reliability Aspects;512
22.1;18.1 Psychological and Philosophical Background of Safety;513
22.2;18.2 De.nitions and Technical Aspects of Safety, Reliability and Dependability;514
22.3;18.3 The AMB as a Mechatronic Product and Failure Examples;515
22.4;18.4 Measures for Reducing Risks of Failure;516
22.5;18.5 Smart Machine Technologies;521
22.6;18.6 Conclusions;525
22.7;References;525
23;Index;529