IEEE Press Series on Power Engineering

Advanced Solutions

in Power Systems

HVDC, FACTS, and Artificial Intelligence

Edited by

MIRCEA EREMIA

CHEN-CHING LIU

ABDEL-ATY EDRIS

ADVANCED SOLUTIONS

IN POWER SYSTEMS

IEEE Press

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Piscataway, NJ 08854

IEEE Press Editorial Board

Tariq Samad, Editor in Chief

George W. Arnold Xiaoou Li Ray Perez

Giancarlo Fortino Vladimir Lumelsky Linda Shafer

Dmitry Goldgof Pui-In Mak Zidong Wang

Ekram Hossain Jeffrey Nanzer MengChu Zhou

Kenneth Moore, Director of IEEE Book and Information Services (BIS)

ADVANCED SOLUTIONS

IN POWER SYSTEMS

HVDC, FACTS, and Artificial Intelligence

Edited by

MIRCEA EREMIA

CHEN-CHING LIU

ABDEL-ATY EDRIS

Copyright © 2016 by The Institute of Electrical and Electronics Engineers, Inc.

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Library of Congress Cataloging-in-Publication Data is available.

ISBN: 978-1-119-03569-5

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

CONTENTS

CONTRIBUTORS xxi

FOREWORD xxiii

ACKNOWLEDGMENTS xxv

CHAPTER 1 INTRODUCTION 1

Mircea Eremia, Chen-Ching Liu, and Abdel-Aty Edris

PART I HVDC TRANSMISSION

Mircea Eremia

CHAPTER 2 POWER SEMICONDUCTOR DEVICES FOR HVDC AND

FACTS SYSTEMS 11

Remus Teodorescu and Mircea Eremia

2.1 Power Semiconductor Overview 12

2.1.1 Not-Controllable Power Semiconductor Devices 13

2.1.2 Semicontrollable Power Semiconductor Devices 13

2.1.3 Fully Controllable Power Semiconductor Devices 17

2.1.3.1 Gate Turn-Off Thyristor 18

2.1.3.2 Integrated Gate-Commutated Thyristor 18

2.1.3.3 Isolated Gate Bipolar Transistor 18

2.1.4 Power Semiconductor Parameters 20

2.1.4.1 Steady-State Parameters 20

2.1.4.2 Switching Characteristics 20

2.1.5 Future Power Semiconductor Devices 21

2.2 Converter Types 21

2.3 HVDC Evolution 23

2.3.1 Line-Commutated HVDC Converters (LCC/CSC–HVDC) 24

2.3.2 Capacitor-Commutated Converter (CCC–HVDC) 26

2.3.3 Voltage Source Converter VSC–HVDC 28

2.3.3.1 VSC–HVDC Based on Two-Level Converters 29

2.3.3.2 VSC–HVDC Based on Multilevel Converters 29

2.3.3.3 Limitations of VSC Transmission 30

2.4 FACTS Evolution 30

References 33

v

vi CONTENTS

CHAPTER 3 CSC–HVDC TRANSMISSION 35

Mircea Eremia and Constantin Bulac

3.1 Structure and Configurations 35

3.1.1 Structure of HVDC Links 35

3.1.2 HVDC Configurations 40

3.2 Converter Bridge Modeling 47

3.2.1 Rectifier Equations 47

3.2.1.1 Ideal Converter Bridge Operation 47

3.2.1.2 Commutation Process or Overlap 52

3.2.1.3 Equivalent Circuit of the Rectifier 56

3.2.2 Inverter Equations 57

3.3 Control of CSC–HVDC Transmission 59

3.3.1 Equivalent Circuit and Control Characteristics 59

3.3.1.1 Equivalent Circuit of DC Transmission Link 59

3.3.1.2 Voltage–Current Characteristics 62

3.3.2 HVDC Control Principles 64

3.3.2.1 State Variables of a HVDC Link 64

3.3.2.2 Basic Control Principles of the DC Voltage and DC Current 65

3.3.2.3 Control Modes 67

3.3.3 HVDC Control Strategies 69

3.3.3.1 Rectifier Control Strategy 69

3.3.3.2 Inverter Control Strategy 71

3.3.4 Hierarchical Control of a HVDC Link 72

3.3.4.1 Master Control 72

3.3.4.2 Pole Control 74

3.3.4.3 Firing (Valve) Control 78

3.3.4.4 Telecommunications 78

3.3.4.5 Measurement Transducers 78

3.4 Reactive Power and Harmonics 78

3.4.1 Reactive Power Requirements and Sources 78

3.4.2 Harmonics and Filters 83

3.4.2.1 The Source of AC Harmonic Currents 83

3.4.2.2 The Effect of Y∕Δ Transformation on AC Harmonic Current 85

3.4.2.3 Higher Pulse Operation Using Multiple Bridges

and Transformers 86

3.4.2.4 Elimination of Harmonics 86

3.5 Load Flow in Mixed HVAC/HVDC-CSC Systems 91

3.5.1 Steady-State Model 91

3.5.1.1 The Extended Variables Method 93

3.5.1.2 The Sequential Method 94

3.5.1.3 The Eliminated Variables Method 94

3.6 Interaction Between AC and DC Systems 96

3.6.1 AC Systems Stabilization 96

3.6.2 Influence of AC System Short-Circuit Ratio 96

3.6.3 Effective Inertia Constant 99

3.6.4 Reactive Power and the Strength of the AC System 100

3.7 Comparison Between DC and AC Transmission 101

3.8 Application on a CSC–HVDC Link 109

3.8.1 Solution 111

CONTENTS vii

Appendix 3.1 CSC–HVDC Systems in the World 118

References 123

CHAPTER 4 VSC–HVDC TRANSMISSION 125

Mircea Eremia, Jose Antonio Jardini, Guangfu Tang, and Lucian Toma ´

4.1 VSC Converter Structures 126

4.1.1 Half-Bridge VSC or Two-Level Pole 126

4.1.2 Full-Bridge Single-Phase VSC 128

4.1.3 Three-Phase Two-Level VSC 128

4.1.4 Three-Level Pole VSC 129

4.1.5 Multimodule VSC Systems 131

4.1.6 Multilevel VSC Systems 132

4.1.7 Modular Multilevel Converter 138

4.1.7.1 Half-Bridge Modular Multilevel Converter 140

4.1.7.2 Full-Bridge Modular Multilevel Converter 143

4.1.7.3 The MMC–HVDC INELFE Project 144

4.1.8 Cascaded Two-Level Converters 147

4.2 Modulation Techniques 151

4.2.1 PWM Techniques 151

4.2.1.1 PWM Principle 151

4.2.1.2 PWM Strategy Control of a Half-Bridge Converter 155

4.2.1.3 Three-Phase Bridge Inverter with Sinusoidal PWM 159

4.2.2 Modulation Techniques for Multilevel Converters 163

4.2.2.1 PWM Algorithms for Multilevel Converters 163

4.2.2.2 Space Vector Modulation Algorithms 165

4.2.2.3 Other Modulation and Control Algorithms for Multilevel

Converters 165

4.3 DC/AC Converter Analysis 166

4.3.1 Operation Modes of the Switched-Inductor Cell 166

4.3.2 Ideal DC/AC Half-Bridge Converter 168

4.3.3 Averaging Models 175

4.3.3.1 Circuit/Switch Averaging of DC–DC Converters 176

4.3.3.2 State-Space Averaging of DC–DC Converters 177

4.3.3.3 AVM of DC–AC Converters 178

4.3.4 Detailed and Averaged Models for MMC–HVDC Systems 180

4.3.4.1 Detailed Equivalent Models 181

4.3.4.2 AVM of MMC–HVDC Using Voltage- and

Current-Controlled Sources 183

4.4 VSC Transmission Scheme and Operation 188

4.4.1 Power Equipment 188

4.4.2 Principles of Active and Reactive Power Control 192

4.4.3 VSC Transmission Control 196

4.4.3.1 VSC Converter Control Using the Vector Control Strategy 196

4.4.3.2 Levels of Control 199

4.4.3.3 Coordination of Controls 200

4.5 Multiterminal VSC–HVDC Systems and HVDC Grids 203

4.5.1 On the Conventional Multiterminal HVDC Configurations 203

4.5.2 Multiterminal HVDC Grid Configurations 204

4.5.3 Meshed HVDC Grid Configurations 209

viii CONTENTS

4.5.4 Need for Fast and Low Loss HVDC Breakers 211

4.5.4.1 Preconditions 211

4.5.4.2 Schemes for the Current Zero Formation 212

4.5.4.3 Types of DC Circuit Breakers 214

4.5.5 HVDC Grid Protection 218

4.6 Load Flow and Stability Analysis 221

4.6.1 Load Flow in Meshed AC/DC Grids 221

4.6.1.1 Generalities 221

4.6.1.2 Load Flow Calculation in a DC Grid 223

4.6.1.3 Application 227

4.6.2 Dynamic Stability in Meshed AC/DC Grids 231

4.6.2.1 Generalities 231

4.6.2.2 Description of the VSC Model for Stability Analysis 233

4.6.2.3 Control Models 235

4.6.2.4 P–V Droop Control 237

4.6.2.5 Current and Voltage Limits 237

4.6.2.6 RMS Model Testing 238

4.6.2.7 Simulations on an AC/DC Meshed Grid 239

4.7 Comparison of CSC–HVDC Versus VSC–HVDC Transmission 246

4.7.1 Differences Resulting from the Commutation Principle 246

4.7.2 Differences Resulting from the Converter Type 248

4.8 Forward to Supergrid 249

4.8.1 Challenges and Solutions for Developing Supergrid 249

4.8.1.1 Connecting Renewable Energy Sources and Increased

Transmission System Capacity 250

4.8.1.2 Compensating Reactive Power 250

4.8.1.3 Maintaining System Stability 252

4.8.2 Hybrid AC and DC Systems 252

4.8.3 Supernodes 254

4.8.4 Stepwise Development of the European Supergrid 255

4.8.5 Steps Toward a Planetary Supergrid 258

4.8.6 VSC Multiterminal in China 260

Appendix 4.1 VSC–HVDC Projects Around the World 261

Appendix 4.2 Examples of VSC–HVDC One-Line Diagrams 263

References 263

PART II FACTS TECHNOLOGIES

Abdel-Aty Edris and Mircea Eremia

CHAPTER 5 STATIC VAr COMPENSATOR (SVC) 271

Mircea Eremia, Aniruddha Gole, and Lucian Toma

5.1 Generalities 271

5.2 Thyristor-Controlled Reactor 273

5.3 Thyristor-Switched Capacitor 284

5.4 Configurations of SVC 287

5.4.1 Fixed Capacitor and Thyristor-Controlled Reactor 287

5.4.2 The SVC Device (TSC–TCR) 289

5.4.2.1 V–I Characteristics 289

5.4.2.2 Operating Domain 290

CONTENTS ix

5.5 Control of SVC Operation 294

5.5.1 The Voltage Regulator 294

5.5.2 Gate Pulse Generator 296

5.6 SVC Modeling 296

5.6.1 Steady-State SVC Modeling 296

5.6.1.1 Modeling of an SVC That Operates Within or Outside the

Linear Control Domain 297

5.6.1.2 Improved Models for SVC Representation 299

5.6.1.3 Newton–Raphson Modified Algorithm to Include the SVCs 305

5.6.2 SVC Dynamic Modeling 307

5.6.2.1 The Basic Dynamic Model 307

5.6.2.2 First-Order Dynamic Model 308

5.6.2.3 Complex SVC Dynamic Models 309

5.7 Placement of SVC 312

5.8 Applications of SVC 314

5.8.1 Maintaining the Voltage Level of a Bus or into an Area 315

5.8.2 Increasing the Transmission Capacity 315

5.8.3 Static and Transient Stability Reserve Improvement 317

5.8.4 Oscillations Damping 322

5.8.5 Reducing the Transient Overvoltages 323

5.9 SVC Installations Worldwide 324

5.9.1 SVC at Hagby, in Sweden 326

5.9.2 SVC at Forbes, in United States 327

5.9.3 SVC in Temascal, Mexico 328

5.9.4 Complex Compensation Scheme in Argentina 329

5.9.5 SVC in the 735 kV Transmission System in Canada 329

5.9.6 SVC at Auas, in Namibia 330

5.9.7 SVC at the Channel Tunnel Rail Link 333

5.9.8 SVC at Harker, in United Kingdom 334

5.9.9 Relocatable SVCs 336

References 337

CHAPTER 6 SERIES CAPACITIVE COMPENSATION 339

Mircea Eremia and Stig Nilsson

6.1 Generalities 339

6.2 Mechanical Commutation-Based Series Devices 339

6.3 Static-Controlled Series Capacitive Compensation 342

6.3.1 GTO-Controlled Series Capacitor 342

6.3.2 Thyristor-Switched Series Capacitor 345

6.3.3 Thyristor-Controlled Series Capacitor 348

6.3.3.1 Basic Structure 349

6.3.3.2 Operating Principles of TCSC. Steady-State Approach and

Synchronous Voltage Reversal 351

6.3.3.3 Operation Modes and the Characteristics of the TCSC 357

6.3.3.4 Capability Characteristics of the TCSC 362

6.4 Control Schemes for the TCSC 365

6.4.1 Open Loop Impedance Control 365

6.4.2 Closed Loop Control 366

6.5 TCSC Modeling 370

x CONTENTS

6.5.1 Steady-State Modeling of TCSC 370

6.5.1.1 TCSC Modeling Through Series Variable Impedance 370

6.5.1.2 TCSC Impedance Modeling as a Function of the Firing Angle 374

6.5.2 TCSC Dynamic Models 376

6.5.2.1 Transient Stability Model 376

6.5.2.2 Long-Term Stability Model 379

6.6 Applications of TSSC/TCSC Installations 382

6.7 Series Capacitors Worldwide 387

6.7.1 Kanawha River Mechanically Switched Series Capacitor in United

States 387

6.7.2 Kayenta TCSC in United States 389

6.7.3 Slatt TCSC in United States 392

6.7.4 Stode TCSC in Sweden ¨ 396

6.7.5 Imperatriz-Serra da Mesa TCSC in Brazil 397

6.7.6 Purnea and Gorakhpur TCSC/FSC in India 400

6.7.7 Series-Compensated 500 kV Power Transmission Corridors in

Argentina 402

Appendix 6.1 TCSC Systems Around the World 404

References 405

CHAPTER 7 PHASE SHIFTING TRANSFORMER: MECHANICAL AND STATIC

DEVICES 409

Mylavarapu Ramamoorty and Lucian Toma

7.1 Introduction 409

7.2 Mechanical Phase Shifting Transformer 410

7.2.1 Principle of Operation of the PST 410

7.2.2 PST Topology 412

7.2.2.1 Direct-Type Asymmetrical PSTs 412

7.2.2.2 Direct-Type Symmetrical PSTs 414

7.2.2.3 Indirect-Type Asymmetrical and Symmetrical PSTs 416

7.2.2.4 Comparison of the Topologies 417

7.2.3 Steady-State Model of a Mechanical Phase Shifter 418

7.2.4 Equivalent Series Reactance as a Function of the Phase Shift Angle 420

7.2.4.1 Symmetrical Phase Shifter 420

7.2.4.2 Quadrature Booster 424

7.2.4.3 Asymmetrical Phase Shifter 425

7.2.4.4 In-Phase Transformer and Symmetrical/Asymmetrical

Phase Shifter 426

7.3 Thyristor-Controlled Phase Shifting Transformer 428

7.3.1 Configurations of the Static Phase Shifter 428

7.3.1.1 Substitution of Mechanical Tap Changer by Electronic

Switches 429

7.3.1.2 Thyristor-Controlled Quadrature Voltage Injection 429

7.3.1.3 Pulse-Width Modulation AC Controller 432

7.3.1.4 Delay-Angle Controlled AC-AC Bridge Converter 433

7.3.1.5 Discrete-Step Controlled AC-AC Bridge Converter 434

7.3.1.6 PWM Voltage Source Converter 434

7.3.2 Modeling of TCPST 436

7.3.2.1 Model of a Transmission System with a TCPST 436

CONTENTS xi

7.3.2.2 Line Model with Thyristor-Controlled Phase Angle Regulator 437

7.3.2.3 The Dynamic Model of the Phase Shifter 439

7.4 Applications of the Phase Shifting Transformers 439

7.4.1 Power Flow Control by Phase Angle Regulators 440

7.4.2 Real and Reactive Loop Power Flow Control 442

7.4.3 Improvement of Transient Stability with PST 444

7.4.4 Power Oscillation Damping with PST 446

7.4.4.1 Application to Damp Power Oscillations 448

7.5 Phase Shifting Transformer Projects Around the World 450

References 456

CHAPTER 8 STATIC SYNCHRONOUS COMPENSATOR – STATCOM 459

Rafael Mihalic, Mircea Eremia, and Bostjan Blazic

8.1 Principles and Topologies of Voltage Source Converter 459

8.1.1 Basic Considerations 459

8.1.2 Converter Topologies 464

8.1.2.1 Two-Level Topologies 464

8.1.2.2 Multilevel Topologies 469

8.1.2.3 PWM Converter 471

8.1.3 Switching Function 472

8.2 STATCOM Operation 473

8.3 STATCOM Modeling 476

8.3.1 STATCOM Model for Steady-State Analysis 476

8.3.1.1 Basic Load Flow Equations 478

8.3.1.2 The Single-Phase Voltage-Based Model 480

8.3.1.3 The Single-Phase Current-Based Model 482

8.3.1.4 Three-Phase Voltage-Based Model 484

8.3.1.5 Three-Phase Current-Based Model 487

8.3.2 Dynamic Models of STATCOM 492

8.3.2.1 Simplified Dynamic Model 492

8.3.2.2 Detailed Dynamic Model 494

8.3.3 Control Algorithm 499

8.3.4 STATCOM Model for Unbalanced Operation 501

8.4 STATCOM Applications 506

8.4.1 Fast Voltage Control and Maintaining Voltage Levels of a Bus or an Area 506

8.4.2 Flicker Compensation 506

8.4.3 Improvement of the Network Transmission Capability 509

8.4.4 Improvement of Static and Transient Stability Reserve 512

8.4.5 Oscillations Damping 514

8.5 STATCOM Installations in Operation 515

8.5.1 ± 80 MVAr STATCOM in Japan 515

8.5.2 ± 100 MVAr STATCOM at Sullivan, in United States 516

8.5.3 +225/–52 MVAr TSC and STATCOM Mixed System at East Claydon,

in Great Britain 520

8.5.4 +133/–41 MVAr STATCOM at Essex, in United States 520

8.5.5 STATCOM (+80/–110 MVAr) and Mechanic-Switched Capacitor (–93

MVAr) Mixed System, at Holly, in United States 521

8.5.6 ±100 MVAr STATCOM at Talega, in United States 522

References 524

xii CONTENTS

CHAPTER 9 STATIC SYNCHRONOUS SERIES COMPENSATOR (SSSC) 527

Laszlo Gyugyi, Abded-Aty Edris, and Mircea Eremia

9.1 Introduction 527

9.2 Architecture and Operating Principles 528

9.2.1 The Basic Structure and Principles of Operation 528

9.2.2 Operating Modes of SSSC 530

9.2.3 The Pq-δ Characteristic of SSSC 532

9.3 Comparison of SSSC with Other Technologies 533

9.3.1 Comparison with Fixed Series Capacitor 533

9.3.2 Comparison with Fixed Series Reactor 534

9.3.3 Comparison with Phase Angle Regulator 534

9.3.4 Comparison with Thyristor-Controlled Series Capacitor 535

9.3.5 Comparison with Gate-Controlled Series Capacitor 538

9.3.6 Dynamic Flow Controller 540

9.4 Components of an SSSC 540

9.4.1 Overview of the Functional SSSC Components 540

9.4.2 Control 542

9.4.3 Protection 545

9.5 SSSC Modeling 546

9.5.1 Steady-State SSSC Model 546

9.5.1.1 VSC Controller Load Flow Models 546

9.5.1.2 Newton–Raphson Load Flow Solution 547

9.5.2 SSSC Dynamic Model 549

9.6 Applications 551

9.7 SSSC Installation 552

9.7.1 SSSC in Operation 552

9.7.2 SSSC for Power Flow Control: A Project in Spain 553

9.7.2.1 Project Overview 553

9.7.2.2 Components of the SSSC 554

9.7.2.3 Location Selection for Prototype Installation 555

References 556

CHAPTER 10 UNIFIED POWER FLOW CONTROLLER (UPFC) 559

Laszlo Gyugyi

10.1 Introduction 559

10.1.1 UPFC as the Functional Combination of Conventional Transmission

Controllers 559

10.1.2 UPFC Directly Providing Line Current Forcing Function 566

10.2 Basic Characteristics of the UPFC 567

10.3 UPFC Versus Conventional Power Flow Controllers 571

10.3.1 UPFC versus Series Reactive Compensators 571

10.3.2 UPFC versus Phase Shifters 573

10.4 UPFC Control System 575

10.4.1 Functional Control of the Shunt Converter 578

10.4.2 Functional Control of the Series Converter 579

10.4.3 Stand-Alone Shunt and Series Compensation 580

10.4.4 Basic Control Structure for the Series and Shunt Converters 580

10.4.5 Practical Control Considerations 583

CONTENTS xiii

10.5 Equipment Structural and Rating Considerations 584

10.5.1 Circuit Structural Considerations 586

10.5.2 Rating Considerations for Series and Shunt Converters 588

10.5.2.1 Series Converter Rating to Meet Line Compensation

Requirements 588

10.5.2.2 Shunt Converter Rating to Meet UPFC Operation

Requirements 592

10.5.3 UPFC Rating Optimization by Combined Compensation 594

10.6 Protection Considerations 596

10.6.1 Protection of the Series Converter 596

10.6.2 Protection of the Shunt Converter 600

10.7 Application Example: UPFC at AEP’s INEZ Station 600

10.7.1 Background and Planning Information at the Time of Installation 601

10.7.2 UPFC Operation Strategy 603

10.7.3 Description of the UPFC 604

10.7.4 Performance of the UPFC 607

10.7.5 Importance of Results and Possible Future Trends 613

10.8 Modeling of the UPFC Device 613

10.8.1 The Steady-State Model of UPFC 613

10.8.2 Power Flow and Active Power Balance Restrictions 616

10.8.3 Implementing the UPFC Model in the Newton–Raphson Method 618

10.8.4 The Dynamic Model of UPFC 623

References 627

CHAPTER 11 INTERLINE POWER FLOW CONTROLLER (IPFC) 629

Laszlo Gyugyi

11.1 Generalities 629

11.2 Basic Operating Principles and Characteristics of the IPFC 630

11.3 Generalized Interline Power Flow Controller for Multiline Systems 636

11.4 Basic Control System 638

11.5 Equipment Structural and Rating Considerations 640

11.6 Protection Considerations 642

11.7 Application Example: IPFC at NYPA’s Marcy Substation 643

11.7.1 Background Information, System, and Equipment

Requirements 643

11.7.2 Description of the CSC/IPFC 644

11.7.3 Importance of the NYPA Installation 645

References 649

CHAPTER 12 SEN TRANSFORMER: A POWER REGULATING TRANSFORMER 651

Kalyan K. Sen

12.1 Background 651

12.1.1 Traditional Power Flow Controllers 652

12.1.2 Essential Control Parameters and Their Implementations 655

12.2 The Sen Transformer Concept 656

12.2.1 Shunt-Series Configuration for ST 657

12.2.2 Principle of Operation of ST 658