Design, Control, and Application of Modular Multilevel Converters for HVDC Transmission Systems (eBook)

Kamran Sharifabadi, Power Grid & Regulatory Affairs, Statoil, Norway Kamran has twenty-five years of international experience in the field of HVDC technology projects. He started out as a research engineer in ABB and Siemen, worked as a consultant for five years, then became a manager at the Norwegian TSO. He is currently a senior technology advisor for Statoil`s HVDC projects, a guest lecturer in the topics of VSC HVDC, Wind power generation technologies at NTNU and at various different universities in central Europe. Kamran is an active member of the Cigre B4 (HVDC) working group and the leader of the steering committee for a European research project on DC grids. Remus Teodorescu, Aalborg University, Denmark Remus is an Associate Professor at the Institute of Technology, teaching courses in power electronics and electrical energy system control. He has authored over 80 journal and conference papers and two books. He is the founder and coordinator of the Green Power Laboratory at Aalborg University, and is co-recipient of the Technical Committee Prize Paper Award at IEEE Optim 2002. Hans Peter Nee, KTH, Sweden Hans is Professor of Power Electronics in the Department of Electrical Engineering. He has supervised and examined ten finalized doctor's projects, and was awarded the Elforsk Scholarship in 1997. He has served on the board of the IEEE Sweden Section for many years and was Chairman during 2002 and 2003. He is also a member of EPE and serves in the Executive Council and in the International Steering Committee. Lennart Harnefors, ABB, Västerås, Sweden Lennart is currently with ABB Power Systems - HVDC, Ludvika, Sweden as an R&D Project Manager and Principal Engineer, and with KTH as an Adjunct Professor of power electronics. Between 2001 and 2005, he was a part-time Visiting Professor of electrical drives with Chalmers University of Technology, Sweden. He is an Associate Editor of the IEEE Transactions on Industrial Electronics, on the Editorial Board of IET Electric Power Applications, and a member of the Executive Council and the International Scientific Committee of the European Power Electronics and Drives Association. Staffan Norrga, KTH, Sweden Between 1994 and 2011, Staffan worked as a Development Engineer at ABB in Västerås, Sweden, in various power-electronics-related areas such as railway traction systems and converters for HVDC power transmission systems. In 2000, he returned to the Department of Electric Machines and Power Electronics of the Royal Institute of Technology, where he is an associate professor. He is the inventor or co-inventor of 11 granted patents and 14 patents pending and has authored more than 35 scientific papers.

Preface

About the Companion Website

Introduction

1 Introduction to Modular Multilevel Converters

1.1 The Two-Level Voltage Source Converter

1.2 Benefits of Multilevel Converters

1.3 Early Multilevel Converters

1.4 Cascaded Multilevel Converters

1.5 Summary

2 Main-Circuit Design

2.1 Properties and Design Choices of Power Semiconductor Devices for High-Power Applications

2.2 Medium-Voltage Capacitors for Submodules

2.3 Arm Inductors

2.4 Submodule Configurations

2.5 Choice of Main-Circuit Parameters

2.6 Handling of Redundant and Faulty Submodules

2.7 Auxiliary Power Supplies for Submodules

2.8 Start-Up Procedures

2.9 Summary

3 Dynamics and Control

3.1 Introduction

3.2 Fundamentals

3.3 Converter Operating Principle and Averaged Dynamic Model

3.4 Per-Phase Output-Current Control

3.5 Arm-Balancing (Internal) Control

3.6 Three-Phase Systems

3.7 Vector Output-Current Control

3.8 Higher-Level Control

3.9 Control Architectures

3.10 Summary

4 Control Under Unbalanced Grid Conditions

4.1 Grid Requirements

4.2 Shortcomings of Conventional Vector Control

4.3 Positive/Negative-Sequence Extraction (PNSE)

4.4 Injection Reference Strategy

4.5 Component-Based Vector Output-Current Control

4.6 Summary

4.7 References

5 Modulation and Submodule Energy Balancing

5.1 Fundamentals of PulseWidth Modulation

5.2 Carrier-Based Modulation Methods

5.3 Multilevel Carrier-Based Modulation

5.4 Nearest-Level Control

5.5 Submodule Energy Balancing Methods

5.6 Summary

6 Modeling and Simulation

6.1 Introduction

6.2 Leg-Level Averaged (LLA) Model

6.3 Arm-Level Averaged (ALA) Model

6.4 Submodule-Level Averaged (SLA) Model

6.5 Submodule-Level Switched (SLS) Model

6.6 Summary

7 Design and Optimization of MMC-HVDC Schemes for Offshore Wind-Power Plant Application

7.1 Introduction

7.2 The Influence of Regulatory Frameworks on the Development Strategies for Offshore HVDC Schemes

7.3 Impact of Regulatory Frameworks on the Functional Requirements and Design of Offshore HVDC Terminals

7.4 Components of an Offshore MMC-HVDC Converter

7.5 Offshore Platform Concepts

7.6 Onshore HVDC Converter

7.7 Recommended System Studies for Development and Integration of an Offshore HVDC Link to a WPP

8 MMC-HVDC Standards and Commissioning Procedures

8.1 Introduction

8.2 CIGRE and IEC Activities for Standardisation of MMC-HVDC Technology

8.3 MMC-HVDC Commissioning, Factory and Site Acceptance Tests

9 Control and Protection of MMC-HVDC under AC and DC Network Fault Contingencies

9.1 Two-level VSC-HVDC Fault Characteristics under Unbalanced AC Network Contingency

9.2 MMC-HVDC Fault Characteristics under Unbalanced AC Network Contingency

9.3 DC Pole to Ground Short Circuit Fault Characteristics of the Half-bridge MMC-HVDC

9.4 MMC-HVDC Component Failures

9.5 MMC-HVDC Protection Systems

10 MMC-HVDC Transmission Technology and MTDC Networks

10.1 LCC HVDC Transmission Technology

10.2 Modular Multilevel HVDC Transmission Technology

10.3 The European HVDC Projects and MTDC Network Perspectives

10.4 Multiterminal HVDC Configurations

10.5 DC Load Flow Control in MTDC Networks

10.6 DC Grid Control Strategies

10.7 DC Fault Detection and Protection in MTDC Networks

10.8 Fault Detection Methods in MTDC

10.9 DC Circuit Breaker Technologies

10.10 Fault Current Limiters

10.11 The Influence of Grounding Strategy on Fault Currents

10.12 DC Supergrids of the Future

Index