HVDC Grids For Offshore and Supergrid of the Future

This book discusses HVDC grids based on multi-terminal voltage-source converters (VSC), which is suitable for the connection of offshore wind farms and  a possible solution for a continent wide overlay grid. HVDC Grids: For Offshore and Supergrid of the Future begins by introducing and analyzing the motivations and energy policy drives for developing offshore grids and the European Supergrid. HVDC transmission technology and offshore equipment are described in the second part of the book. The third part of the book discusses how HVDC grids can be developed and integrated in the existing power system. The fourth part of the book focuses on HVDC grid integration, in studies, for different time domains of electric power systems. The book concludes by discussing developments of advanced control methods and control devices for enabling DC grids.

• Presents the technology of the future offshore and HVDC grid
• Explains how offshore and HVDC grids can be integrated in the existing power system
• Provides the required models to analyse the different time domains of power system studies: from steady-state to electromagnetic transients

This book is intended for power system engineers and academics with an interest in HVDC or power systems, and policy makers. The book also provides a solid background for researchers working with  VSC-HVDC technologies, power electronic devices, offshore wind farm integration, and DC grid protection.

Dirk Van Hertem is an Assistant Professor within ESAT-ELECTA at KU Leuven, Belgium. Dr. Van Hertem has written over 100 scientific papers in international journals and conferences.

Oriol Gomis-Bellmunt is an Associate Professor in the Technical University of Catalonia (UPC). He is involved in the CITCEA-UPC research group and the Catalonia Institute for Energy Research (IREC).

Jun Liang is a Reader within the School of Engineering at Cardiff University, UK. He's also an Adjunct Professor at Changsha University of Science and Technology and North China Electric Power University.

LIST OF FIGURES xvii
LIST OF TABLES xxv
CONTRIBUTORS xxvii
FOREWORD xxix
PREFACE xxxi
ACKNOWLEDGMENTS xxxv
ACRONYMS xxxvii
PART I HVDC GRIDS IN THE ENERGY VISION OF THE FUTURE
CHAPTER 1 DRIVERS FOR THE DEVELOPMENT OF HVDC GRIDS 3
Dirk Van Hertem
1.1 Introduction 3
1.2 From the Vertically Integrated Industry to Fast Moving Liberalized Market 3
1.3 Drivers for Change 5
1.3.1 Liberalized Energy Market 6
1.4 Investments in the Grid 12
1.5 Towards HVDC Grids 17
1.6 Conclusions 22
CHAPTER 2 ENERGY SCENARIOS: PROJECTIONS ON EUROPE'S FUTURE GENERATION AND LOAD 25
Erik Delarue and Cedric De Jonghe
2.1 Introduction 25
2.2 System Setting 26
2.3 Scenarios for Europe's Energy Provision 34
2.4 Conclusions 40
PART II HVDC TECHNOLOGY AND TECHNOLOGY FOR OFFSHORE GRIDS
CHAPTER 3 HVDC TECHNOLOGY OVERVIEW 45
Gen Li, Chuanyue Li, and Dirk Van Hertem
3.1 Introduction 45
3.2 LCC-HVDC Systems 45
3.3 LCC-HVDC Converter Station Technology 51
3.4 VSC-HVDC Systems 53
3.5 VSC-HVDC Converter Station Technology 53
3.6 Transmission Lines 72
3.7 Conclusions 76
CHAPTER 4 COMPARISON OF HVAC AND HVDC TECHNOLOGIES 79
Hakan Ergun and Dirk Van Hertem
4.1 Introduction 79
4.2 Current Technology Limits 79
4.3 Technical Comparison 82
4.4 Economic Comparison 87
4.5 Conclusions 94
CHAPTER 5 WIND TURBINE TECHNOLOGIES 97
Eduardo Prieto-Araujo and Oriol Gomis-Bellmunt
5.1 Introduction 97
5.2 Parts of the Wind Turbine 98
5.3 Wind Turbine Types 99
5.4 Conclusions 107
CHAPTER 6 OFFSHORE WIND POWER PLANTS (OWPPS) 109
Mikel De Prada-Gil, Jose Luis Dominguez-Garcia,
Francisco Diaz-Gonzalez, and Andreas Sumper
6.1 Introduction 109
6.2 AC OWPPs 111
6.3 DC OWPPs 130
6.4 Other OWPPs Proposals 135
6.5 Conclusions 138
PART III PLANNING AND OPERATION OF HVDC GRIDS
CHAPTER 7 HVDC GRID PLANNING 143
Hakan Ergun and Dirk Van Hertem
7.1 Context of Transmission System Planning 143
7.2 Transmission Expansion Optimization Methodologies 152
7.3 Specialties of Grid Planning with HVDC Technology 155
7.4 Illustrative Examples 157
CHAPTER 8 HVDC GRID LAYOUTS 171
Jun Liang, Oriol Gomis-Bellmunt, and Dirk Van Hertem
8.1 What is an HVDC Grid? 172
8.2 HVDC Grid Topologies 172
8.3 Topologies of HVDC Grids for Offshore Wind Power Transmission 176
8.4 HVDC Converter Station Configuration 183
8.5 Substation Configuration 189
8.6 Conclusions 189
CHAPTER 9 GOVERNANCE MODELS FOR FUTURE GRIDS 193
Muhajir Tadesse Mekonnen, Diyun Huang, and Kristof De Vos
9.1 Introduction 193
9.2 Transmission Grid Planning 194
9.3 Transmission Grid Ownership 197
9.4 Transmission Grid Financing 201
9.5 Transmission Grid Pricing 204
9.6 Transmission Grid Operation 208
9.7 Conclusions 210
CHAPTER 10 POWER SYSTEM OPERATIONS WITH HVDC GRIDS 213
Dirk Van Hertem, Robert H. Renner, and Johan Rimez
10.1 Introduction 213
10.2 Who Operates the HVDC Link or Grid? 214
10.3 Reliability Considerations in Systems with HVDC 217
10.4 Managing Energy Unbalances in the System 223
10.5 Active and Reactive Power Control 226
10.6 Ancillary Services 230
10.7 Grid Codes 235
10.8 Conclusions 235
CHAPTER 11 OPERATION AND CONTROL OF OFFSHORE WIND POWER PLANTS 239
Oriol Gomis-Bellmunt and Monica Aragues-Penalba
11.1 Introduction 239
11.2 System Under Analysis 240
11.3 Control and Protection Requirements 240
11.4 Wind Power Plant Control Structure 245
11.5 Dynamic Simulation of a Simplified Example 249
11.6 Conclusions 254
PART IV MODELING HVDC GRIDS
CHAPTER 12 MODELS FOR HVDC GRIDS 257
Jef Beerten and Dirk Van Hertem
12.1 Introduction 257
12.2 Power System Computation Programs 257
12.3 Modeling Power Electronic Converters 258
12.4 HVDC Grids Modeling Challenges 262
12.5 Conclusions 264
CHAPTER 13 POWER FLOW MODELING OF HYBRID AC/DC SYSTEMS 267
Jef Beerten
13.1 Introduction 267
13.2 Simplified Power Flow Modeling 268
13.3 Detailed Power Flow Modeling 272
13.4 Sequential AC/DC Power Flow 279
13.5 Software Implementation 289
13.6 Test Case 289
13.7 Conclusions 290
CHAPTER 14 OPTIMAL POWER FLOW MODELING OF HYBRID AC/DC SYSTEMS 293
Johan Rimez
14.1 Introduction 293
14.2 Optimal Power Flow: Standard Formulation and Extension 293
14.3 Optimal Power Flow with DC Grids and Converters 299
14.4 Adding Security Constraints 306
14.5 Conclusions 313
CHAPTER 15 CONTROL PRINCIPLES OF HVDC GRIDS 315
Jef Beerten, Agusti Egea, and Til Kristian Vrana
15.1 Introduction 315
15.2 Basic Control Principles 316
15.3 Basic Converter Control Strategies 318
15.4 Advanced Converter Control Strategies 321
15.5 Basic Grid Control Strategies 324
15.6 Advanced Grid Control Strategies 325
15.7 Converter Inner Current Control 326
15.8 System Power Flow Control 328
15.9 Conclusions 330
CHAPTER 16 STATE-SPACE REPRESENTATION OF HVDC GRIDS 333
Eduardo Prieto-Araujo and Fernando Bianchi
16.1 Introduction 333
16.2 Multi-Terminal Grid Modeling 333
16.3 Four-Terminal Grid Example 339
16.4 Conclusions 343
CHAPTER 17 DC FAULT PHENOMENA AND DC GRID PROTECTION 345
Willem Leterme and Dirk Van Hertem
17.1 Introduction 345
17.2 Short-Circuit Faults in the DC Grid 346
17.3 DC Grid Protection 361
17.4 DC Protection Components 366
17.5 Conclusions 368
CHAPTER 18 REAL-TIME SIMULATION EXPERIMENTS OF DC GRIDS 371
Oluwole Daniel Adeuyi and Marc Cheah
18.1 Introduction 371
18.2 Real-Time Simulation in Power Systems 375
18.3 Design of Experimental Test Rig 379
18.4 Potential Applications of HIL Tests in DC Grids 386
PART V APPLICATIONS
CHAPTER 19 POWER SYSTEM OSCILLATION DAMPING BY MEANS OF VSC-HVDC SYSTEMS 391
Jose Luis Dominguez-Garcia and Carlos E. Ugalde-Loo
19.1 Introduction 391
19.2 Power System Stability 392
19.3 VSC-HVDC Systems Damping Contribution: Application Examples 397
19.4 Conclusions 409
CHAPTER 20 OPTIMAL DROOP CONTROL OF MULTI-TERMINAL VSC-HVDC GRIDS 413
Fernando D. Bianchi and Eduardo Prieto-Araujo
20.1 Introduction 413
20.2 Control of Multi-Terminal VSC-HVDC Grids 414
20.3 Time-Varying Description for Droop Control Design 418
20.4 Design of Optimal Control Droops 421
20.5 Four-Terminal VSC-HVDC Network Example 422
20.6 Conclusions 426
CHAPTER 21 DC GRID POWER FLOW CONTROL DEVICES 429
Chunmei Feng, Sheng Wang, and Qing Mu
21.1 DC Power Flow Control Devices (DCPFC) 430
21.2 Generic Modeling of DC Power Flow Control Devices 437
21.3 Sensitivity Analysis of DCPFC in DC Grid 438
21.4 Case Study of Power Flow Control Devices in DC Grids 441
21.5 Control Sensitivity of DCPFC in DC Grids 444
21.6 Comparison of Power Control Devices 448
21.7 Conclusions 450
CHAPTER 22 MODELING AND CONTROL OF OFFSHORE AC HUB 451
Xiaobo Hu, Jun Liang, and Jose Luis Dominguez-Garcia
22.1 Reasons for Developing AC Hub 451
22.2 What is the AC Hub? 452
22.3 Frequency-Dependent Modeling of AC Hub Components 455
22.4 AC Hub Control Using Variable Frequency 460
22.5 Conclusions 469