Fundamental Elements of Applied Superconductivity in Electrical Engineering

The superconducting technology is potential important technology and one of future smart grid technologies, it is a combination of superconductor material, electrical engineering, cryogenic insulation, cryogenic, cryostat. There is no such specific book systematically involving those full of science and technology in electrical engineering. The book can include those areas, and is essential for people majoring applied superconductivity in electrical engineering.  Recently, the superconducting technology has made great progress. Many Universities, companies involve in the applied superconductivity under supporting by government.

In next 5 years, many people from schools of electrical engineering of University and companies will involve in this area. The people can directly do research on applied superconductivity in electrical engineering after learning the book. It is more comprehensive and practical compared with other advances.

Presents a clear introduction to the application of superconductor in electrical engineering and related fundamental technologies Arms readers with the technological aspects of superconductivity required to produce a machine Covers power supplying technologies in superconducting electric apparatus Well organized and adaptable by students, lecturers, researchers and engineers

Preface xiii

Acknowledgments xv

Abbreviations and Symbols xvii

1 Introduction 1

References 3

2 Superconductivity 5

2.1 The Basic Properties of Superconductors 5

2.2 Critical Parameters 17

2.3 Classification and Magnetization 19

2.4 Measurement Technologies of Critical Parameters 27

References 43

3 Mechanical Properties and Anisotropy of Superconducting Materials 45

3.1 Mechanical Properties 45

3.2 Electromagnetic Anisotropy 48

3.3 Critical Current Characteristics of LTS Materials 57

3.4 Irreversible Fields of Superconducting Materials 60

3.5 Critical Temperature of Several Kinds of HTS Materials 61

3.6 Thermodynamic Properties of Practical Superconducting Materials 62

References 67

4 Stability of Superconductors 71

4.1 Critical States 72

4.2 Adiabatic Stabilization 72

4.3 Adiabatic Stability with Flux Jump 75

4.4 Self–Field Stability 79

4.5 Dynamic Stability 82

4.6 Cryostability 95

4.7 NPZ Velocity in Adiabatic Composite Superconductors 105

4.8 Stability of HTS Bulks 109

4.9 Mechanical Stability of Superconducting Magnets 112

4.10 Degradation and Training Effect of Superconducting Magnets 113

4.11 Quench and Protection of Superconducting Magnets 114

4.12 Tests of Stability 135

References 139

5 AC Losses 141

5.1 AC Losses of Slab 142

5.2 AC Losses of Concentric Cylinder 156

5.3 AC Losses of Hybrid Concentric Cylinder 165

5.4 AC Losses of Concentric Hollow Cylinder in Longitudinal Field 167

5.5 AC Losses for Large Transverse Rotating Field 167

5.6 AC Losses with Different Phases between AC Field and AC Current 168

5.7 AC Losses for other Waves of AC Excitation Fields 175

5.8 AC Losses for other Critical State Models 177

5.9 Other AC Losses 182

5.10 Measurements of AC Loss 194

5.11 AC Losses Introduction of Superconducting Electrical Apparatus 204

References 206

6 Brief Introduction to Fabricating Technologies of Practical Superconducting Materials 209

6.1 NbTi Wire 211

6.2 Nb3Sn Wire 213

6.3 Nb3Al Wire 215

6.4 MgB2 Wire 216

6.5 BSCCO Tape/Wire 216

6.6 YBCO Tape 221

6.7 HTS Bulk 223

References 226

7 Principles and Methods for Contact–Free Measurements of HTS Critical Current and n Values 229

7.1 Measurement Introduction of Critical Current and n Values 229

7.2 Critical Current Measurements of HTS Tape by Contact–Free Methods 230

7.3 n Value Measurements of HTS Tape by Contact–Free Methods 235

7.4 Analysis on Uniformity of Critical Current and n Values in Practical Long HTS Tape 238

7.5 Next Measurements of Critical Currents and n Values by Contact–Free Methods 240

References 240

8 Cryogenic Insulating Materials and Performances 243

8.1 Insulating Properties of Cryogenic Gas 243

8.2 Insulating Characteristics of Cryogenic Liquid 248

8.3 Insulating Properties of Organic Insulating Films 256

8.4 Cryogenic Insulating Paints and Cryogenic Adhesive 269

8.5 Structural Materials for Cryogenic Insulation 271

8.6 Inorganic Insulating Materials 273

References 278

9 Refrigeration and Cryostats 279

9.1 Cryogens 280

9.2 Cryostat 281

9.3 Refrigeration 310

9.4 Cooling Technologies of Superconducting Electric Apparatus 317

References 323

10 Power Supplying Technology in Superconducting Electrical Apparatus 325

10.1 Current Leads 326

10.2 Superconducting Switch 352

10.3 Flux Pump 357

References 361

11 Basic Structure and Principle of Superconducting Apparatus in Power System 363

11.1 Cable 363

11.2 Fault Current Limiter 366

11.3 Transformer 374

11.4 Rotating Machine–Generator/Motor 376

11.5 Superconducting Magnetic Energy Storage (SMES) 379

11.6 Superconducting Flywheel Energy Storage (SFES) 382

11.7 Other Industrial Applications 384

References 387

12 Case Study of Superconductivity Applications in Power System–HTS Cable 389

12.1 Design of AC/CD HTS Cable Conductor 389

12.2 Electromagnetic Design of AC/CD Cable Conductor 395

12.3 Analysis on AC Losses of DC HTS Cable 399

12.4 Design of AC WD HTS Cable Conductor 404

12.5 Design of DC HTS Cable Conductor 405

12.6 Design of Cryostat 408

12.7 Manufacture of CD HTS Cable Conductor 410

12.8 Bending of HTS Cable 412

12.9 Termination and Joint 412

12.10 Circulating Cooling System and Monitoring System 415

References 419

Appendix 421

A.1 Calculations of Volumetric Heat Capacity, Thermal Conductivity and Resistivity of Composite Conductor 421

A.2 Eddy Current Loss of Practical HTS Coated Conductor (YBCO CC) 422

A.3 Calculation of Geometrical Factor G 425

A.4 Derivation of Self and Mutual Inductances of CD Cable 426

A.5 Other Models for Hysteresis Loss Calculations of HTS Cable 429

A.6 Cooling Arrangements 430

References 438

Index 439

Yinshun Wang, North China Electric Power University, China