Electrical Machines With MATLAB : Second Edition

Second

Edition

ELECTRICAL MACHINES with MATLAB* TURAN GONEN

CRC Press Taylor & Francis Group Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business

Contents Preface to the First Edition Preface to the Second Edition Acknowledgments Author Chapter 1

Chapter 2

Chapter 3

Basic Concepts

xiii xv xvii xix 1

1.1 Introduction 1.2 Distribution System 1.3 Impact of Dispersed Storage and Generation 1.4 Brief Overview of Basic Electrical Machines 1.5 Real and Reactive Powers in Single-Phase AC Circuits Problems

1 4 5 7 9 14

Three-Phase Circuits

17

2.1 2.2

Introduction Three-Phase Systems 2.2.1 Ideal Three-Phase Power Sources 2.2.1.1 Wye-Connected Ideal Three-Phase Source 2.2.1.2 Delta-Connected Ideal Three-Phase Source 2.2.2 Balanced Three-Phase Loads 2.3 Unbalanced Three-Phase Loads 2.4 Measurement of Average Power in Three-Phase Circuits 2.5 Power Factor Correction Problems

17 17 18 21 24 24 33 37 41 44

Magnetic Circuits

53

3.1 3.2 3.3 3.4 3.5 3.6 3.7

53 53 56 58 66 68 72 72 72 81 82 82 83 85 88

Introduction Magnetic Field of Current-Carrying Conductors Ampere's Magnetic Circuital Law Magnetic Circuits Magnetic Circuit with Air Gap Brief Review of Ferromagnetism Magnetic Core Losses 3.7.1 Hysteresis Loss 3.7.2 Eddy-Current Loss 3.8 How to Determine Flux for a Given MMF 3.8.1 Trial-and-Error Method 3.8.2 Graphical Method 3.8.3 Magnetization Curve Method 3.9 Permanent Magnets Problems

V

vi

Chapter 4

Contents

Transformers 4.1 4.2 4.3 4.4

Introduction Transformer Construction Brief Review of Faraday's and Lenz's Laws of Induction Ideal Transformer 4.4.1 Dot Convention in Transformers 4.4.2 Impedance Transfer through a Transformer 4.4.3 Relationship between Input and Output Powers of an Ideal Transformer 4.5 Real Transformer 4.6 Approximate Equivalent Circuit of a Real Transformer 4.7 Determination of Equivalent-Circuit Parameters 4.7.1 Open-Circuit Test 4.7.2 Short-Circuit Test 4.8 Transformer Nameplate Rating 4.9 Performance Characteristics of a Transformer 4.9.1 Voltage Regulation of a Transformer 4.9.2 Transformer Efficiency 4.10 Three-Phase Transformers 4.11 Three-Phase Transformer Connections 4.12 Autotransformers 4.13 Three-Winding Transformers 4.14 Instrument Transformers 4.15 Inrush Current Problems Chapter 5 Electromechanical Energy Conversion Principles

Chapter 6

93 93 97 98 101 104 105 107 113 116 121 121 123 124 129 129 134 138 140 146 152 153 154 156 165

5.1 5.2 5.3

Introduction Fundamental Concepts Electromechanical Energy Conversion 5.3.1 Field Energy 5.3.2 Magnetic Force 5.3.3 Energy and Coenergy 5.3.4 Magnetic Force in a Saturable System 5.4 Study of Rotating Machines 5.5 Singly Excited Rotating Systems 5.6 Multiply Excited Rotating Systems 5.7 Cylindrical Machines 5.7.1 Single-Phase Synchronous Machine 5.7.2 Single-Phase Induction Machine 5.8 Force Produced on a Conductor 5.9 Induced Voltage on a Conductor Moving in a Magnetic Field Problems

165 165 175 177 183 185 185 188 188 193 197 199 199 200 202 204

Induction Machines

207

6.1 6.2

207 211

Introduction Construction of Induction Motors

vii

Contents

6.3

Rotating Magnetic Field Concept 6.3.1 Graphical Method 6.3.2 Analytical Method 6.4 Induced Voltages 6.5 Concept of Rotor Slip 6.6 Effects of Slip on the Frequency and Magnitude of Induced Voltage of the Rotor 6.7 Equivalent Circuit of an Induction Motor 6.7.1 Stator Circuit Model 6.7.2 Rotor-Circuit Model 6.7.3 Complete Equivalent Circuit 6.7.4 Approximate Equivalent Circuit 6.8 Performance Calculations 6.9 Equivalent Circuit at Start-Up 6.10 Determination of Power and Torque by Use of Thevenin's Equivalent Circuit 6.11 Performance Characteristics 6.12 Control of Motor Characteristics by Squirrel-Cage Rotor Design 6.13 Starting of Induction Motors 6.13.1 Direct-on-Line Starting 6.13.2 Reduced-Voltage Starting 6.13.3 Current Limiting by Series Resistance or Impedance 6.14 Speed Control 6.15 Tests to Determine Equivalent-Circuit Parameters 6.15.1 No-Load Test 6.15.2 DC Test 6.15.3 Blocked-Rotor Test Problems Chapter 7 Synchronous Machines 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10

Introduction Construction of Synchronous Machines Field Excitation of Synchronous Machines Synchronous Speed Synchronous Generator Operation Equivalent Circuits Synchronous Motor Operation Power and Torque Characteristics Stiffness of Synchronous Machines Effect of Changes in Excitation 7.10.1 Synchronous Machine Connected to an Infinite Bus 7.10.2 Synchronous Generator Operating Alone 7.11 Use of Damper Windings to Overcome Mechanical Oscillations 7.12 Starting of Synchronous Motors 7.13 Operating a Synchronous Motor as a Synchronous Condenser 7.14 Operating a Synchronous Motor as a Synchronous Reactor 7.15 Tests to Determine Equivalent-Circuit Parameters 7.15.1 Open-Circuit Test 7.15.2 Short-Circuit Test

213 214 216 219 220 222 225 225 226 228 229 230 236 241 243 249 251 252 253 254 259 260 261 261 262 267 273 273 273 276 277 278 282 288 288 293 294 294 297 298 298 299 300 301 301 302

viii

Chapter 8

Chapter 9

Contents

7.15.3 DC lest 7.15.4 Unsaturated Synchronous Reactance 7.15.5 Saturated Synchronous Reactance 7.15.6 Short-Circuit Ratio 7.16 Capability Curve of Synchronous Machine 7.17 Parallel Operation of Synchronous Generators Problems

302 303 304 304 305 306 308

Direct-Current Machines

313

8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11 8.12 8.13 8.14 8.15 8.16 8.17 8.18 8.19 8.20

Introduction Constructional Features Brief Review of Armature Windings Elementary DC Machine Armature Voltage Methods of Field Excitation Armature Reaction Commutation Compensating Windings Magnetization Curve DC Generators Separately Excited Generator Self-Excited Shunt Generator Series Generator Compound Generator Voltage Regulation Developed Power Developed Torque Power Flow and Efficiency DC Motor Characteristics 8.20.1 Speed Regulation 8.20.2 Speed-Current Characteristic 8.20.3 Speed-Torque Characteristic 8.20.4 Torque-Current Characteristic 8.20.5 Internal Generated Voltage-Current Characteristic 8.21 Control of DC Motors 8.22 DC Motor Starting 8.23 DC Motor Braking Problems

313 313 316 318 319 323 323 325 327 328 332 332 333 335 336 337 341 342 343 348 348 349 350 351 351 355 358 364 366

Single-Phase and Special-Purpose Motors

371

9.1 9.2

371 371 374 374 380 381 381 382 383

9.3 9.4

Introduction Single-Phase Induction Motors 9.2.1 Equivalent Circuit 9.2.2 Performance Analysis Starting of Single-Phase Induction Motors Classification of Single-Phase Induction Motors 9.4.1 Split-Phase Motors 9.4.2 Capacitor-Start Motors 9.4.3 Capacitor-Run Motors

Contents

ix

9.4.4 Capacitor-Start Capacitor-Run Motors 9.4.5 Shaded-Pole Motors 9.5 Universal Motors 9.6 Single-Phase Synchronous Motors 9.6.1 Reluctance Motors 9.6.2 Hysteresis Motors 9.6.3 Stepper Motors 9.7 Subsynchronous Motors 9.8 Permanent-Magnet DC Motors Problems Chapter 10 Transients and Dynamics of Electric Machines 10.1 Introduction 10.2 DC Machines 10.3 Separately Excited DC Generator 10.3.1 Field-Circuit Transient 10.3.2 Armature-Circuit Transient 10.4 Separately Excited DC Motor 10.5 Synchronous Generator Transients 10.6 Short-Circuit Transients 10.7 Transient Stability 10.8 Swing Equation Problems Chapter 11 Renewable Energy 11.1 Introduction 11.2 Renewable Energy 11.3 Impact of Dispersed Storage and Generation 11.4 Integrating Renewables into Power Systems 11.5 Distributed Generation 11.6 Renewable Energy Penetration 11.7 Active Distribution Network 11.8 Concept of Microgrid References Chapter 12 Wind Energy and Wind Energy Conversion System (WECS) 12.1 Introduction 12.2 Advantages and Disadvantages of Wind Energy Conversion Systems 12.2.1 Advantages of a Wind Energy Conversion System 12.2.2 Disadvantages of a Wind Energy Conversion System 12.3 Categories of Wind Turbines 12.4 Visual Impact of Wind Turbines 12.5 Types of Generators Used in Wind Turbines 12.6 Wind Turbine Operating Systems 12.6.1 Constant-Speed Wind Turbines 12.6.2 Variable-Speed Wind Turbine System 12.7 Meteorology of Wind 12.8 Power in the Wind

384 384 387 390 390 391 392 394 394 398 401 401 401 401 403 404 408 413 413 419 420 424 427 427 428 429 429 430 431 431 431 434 435 435 436 437 437 437 441 442 444 444 445 446 449

x

Contents

12.9 12.10 12.11 12.12 12.13 12.14

Effects of a Wind Force Impact of Tower Height on Wind Power Wind Measurements Characteristics of a Wind Generator Efficiency and Performance Efficiency of a Wind Turbine 12.14.1 Generator Efficiency 12.14.2 Gearbox 12.14.3 Overall Efficiency 12.15 Other Factors to Define the Efficiency 12.16 Grid Connection 12.17 Some Further Issues Related to Wind Energy 12.18 Development of Transmission System for Wind Energy in the United States 12.19 Energy Storage 12.20 Wind Power Forecasting Problems References Chapter 13 Solar Energy Systems 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 13.13 13.14 13.15 13.16

Introduction Crystalline Silicon Effect of Sunlight on Solar Cell's Performance Effects of Changing Strength of the Sun on a Solar Cell Temperature's Effect on Cell Characteristics Efficiency of Solar Cells Interconnection of Solar Cells Overall System Configuration Thin-Film PV Concentrating PV PV Balance of Systems Types of Conversion Technologies Linear CSP Systems Power Tower CSP Systems Dish/Engine CSP Systems PV Applications 13.16.1 Utility-Interactive PV Systems 13.16.2 Stand-Alone PV Systems Problems References Chapter 14 Energy Storage Systems 14.1 Introduction 14.2 Storage Systems 14.3 Storage Devices 14.3.1 Large Hydro 14.3.2 Compressed-Air Storage 14.3.3 Pumped Hydro 14.3.4 Hydrogen

452 453 455 456 458 461 461 461 462 462 464 465 466 466 467 469 469 471 471 472 476 477 480 482 483 485 487 488 488 488 489 489 489 490 490 490 490 491 493 493 493 494 494 495 495 496

Contents

xi 14.3.5 14.3.6 14.3.7 14.3.8 14.3.9 14.4 Battery 14.4.1 14.4.2 14.4.3

High-Power Flow Batteries High-Power Fly wheels High-Power Supercapacitors Superconducting Magnetic Energy Storage Heat or Cold Storage Types Secondary Batteries Sodium-Sulfur Batteries Flow Battery Technology 14.4.3.1 Zinc-Bromine Flow Battery 14.4.3.2 Vanadium Redox Flow Battery 14.4.4 Lithium-Ion Batteries 14.4.4.1 Lithium Titanate Batteries 14.4.4.2 Lithium Iron Phosphate Batteries 14.4.5 Lead-Acid Batteries 14.4.5.1 Advanced Lead-Acid Batteries 14.4.6 Nickel-Cadmium Batteries 14.5 Operational Problems in Battery Usage 14.6 Fuel Cells 14.6.1 Types of Fuel Cells 14.6.1.1 Polymer Electrolyte Membrane 14.6.1.2 Phosphoric Acid Fuel Cell 14.6.1.3 Molten Carbonate Fuel Cell 14.6.1.4 Solid Oxide Fuel Cell References Chapter 15 The Smart Grid 15.1 15.2 15.3 15.4 15.5 15.6

Introduction Need for Establishment of Smart Grid Roots of the Motivation for the Smart Grid Distribution Automation Active Distribution Networks Volt/Var Control in Distribution Networks 15.6.1 Traditional Approach to Volt/Var Control in the Distribution Networks 15.6.2 SCADA Approach to Control Volt/Var in the Distribution Networks 15.6.3 Integrated Volt/Var Control Optimization 15.7 Existing Electric Power Grid 15.8 Supervisory Control and Data Acquisition 15.9 Advanced SCADA Concepts 15.10 Substation Controllers 15.11 Advanced Developments for Integrated Substation Automation 15.12 Evolution of Smart Grid 15.13 Smart Microgrids 15.14 Topology of aMicrogrid 15.15 Topology of a Smart Grid 15.16 Standards of Smart Grids 15.17 Existing Challenges to the Application of the Concept of Smart Grids References

496 497 497 497 498 499 499 499 500 501 501 501 501 501 501 502 502 502 503 505 506 506 507 507 508 509 509 512 513 516 517 517 517 519 521 523 524 526 527 528 531 534 535 535 535 537 538

xii

Contents

Appendix A: Brief Review of Phasors

539

Appendix B: Per-Unit System

547

Appendix C: Salient-Pole Synchronous Machines

569

Appendix D: Unit Conversions from the English System to SI System

577

Appendix E: Unit Conversions from the SI System to English System

579

Appendix F: Stator Windings

581

Appendix G: Glossary for Electrical Machines Terminology

585

Answers to Selected Problems

615

Bibliography

619

Index

623