Examination of Power Systems Solutions Considering High Voltage Direct Current Transmission Daniel Keith Ridenour Thesis Submitted to the Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Master of Science In Electrical Engineering Jaime De La Ree Lopez, Chair Virgilio A. Centeno Rolando P. Burgos R. Matthew Gardner September 16, 2015 Blacksburg, Virginia Keywords: HVDC transmission, voltage source converter, insulated gate bipolar transistor, line congestion alleviation, interconnection of nondispatchable generation, urban infeed Examination of Power Systems Solutions Considering High Voltage Direct Current Transmission Daniel Keith Ridenour Abstract Since the end of the Current Wars in the 19th Century, alternating current (AC) has dominated the production, transmission, and use of electrical energy. The chief reason for this dominance was (and continues to be) that AC offers a way minimize transmission losses yet transmit large power from generation to load. With the Digital Revolution and the entrance of most of the post-industrialized world into the Information Age, energy usage levels have increased due to the proliferation of electrical and electronic devices in nearly all sectors of life. A stable electrical grid has become synonymous with a stable nation-state and a healthy populace. Large-scale blackouts around the world in the 20th and the early 21st Centuries highlighted the heavy reliance on power systems and because of that, governments and utilities have strived to improve reliability. Simultaneously occurring with the rise in energy usage is the mandate to cut the pollution by generation facilities and to mitigate the impact grid expansion has on environment as a whole. The traditional methods of transmission expansion are beginning to show their limits as utilities move generation facilities farther from load centers, which reduces geographic diversity, and the integration of nondispatchable, renewable energy sources upsets the current operating regime. A challenge faces engineers – how to expand generation, expand transmission capacity, and integrate renewable energy sources while maintaining maximum system efficiency and reliability. A technology that may prove beneficial to the operation of power system is high voltage direct current transmission. The technology brings its own set of advantages and disadvantages, which are in many ways the complement of AC. It is important to update transmission planning processes to account for the new possibilities that HVDC offers. This thesis submits a discussion of high voltage direct current transmission technology itself and an examination of how HVDC can be considered in the planning process. To my parents, Jeffrey and Katharine Ridenour, to my sister, Ashley Ridenour, and to my grandmother, Juanita Grieco, for their unconditional love and unwavering support in all aspects of my life. To my friends of ∑∑ for helping me through undergrad and grad school and for the innumerable hours spent together in friendship. iii Acknowledgements I would like to thank my advisor, Dr. Jaime De La Ree Lopez, for his support of my research. His experience, insight, and knowledge have been invaluable to my success in graduate school. I would also like to thank Dr. Virgilio Centeno for sitting on my committee, his assistance in the pursuit of my degree, and his advice. I would also like to thank Dr. Rolando Burgos for sitting on my committee and his assistance in the pursuit of my degree. I would like to thank Dominion Virginia Power for providing my funding and especially Dr. Matthew Gardner for their assistance. I would like to thank Dr. Ryan Quint for answering my endless emails and questions over this whole process and for the moral support. I would like to thank Mr. M. Kyle Thomas for answering my questions and helping me obtain needed information. I would like to thank my friend, Tristan Flowers, for his years of friendship and support from a world away. I would like to thank my colleagues, Brian Cassidy, Taylor Yeago, Thomas O’Connor, and Kevin McDermott, for their assistance in the pursuit of my degree and for their encouragement and friendship. I would like to thank my fellow graduate students in the Power Lab for their advice and constructive critique of my work. iv Table of Contents Abstract ......................................................................................................................................................... ii Acknowledgements ...................................................................................................................................... iv Table of Contents .......................................................................................................................................... v List of Figures .............................................................................................................................................. vii List of Tables ................................................................................................................................................ ix Chapter 1: Introduction ............................................................................................................................... 1 1.1 Advantages of HVDC Transmission [1] .......................................................................................... 2 1.2 Disadvantages of HVDC Transmission [1] ..................................................................................... 4 Chapter 2: Historical HVDC Transmission .................................................................................................... 8 2.1 Mercury Arc Valves ....................................................................................................................... 8 2.2 Thyristors ...................................................................................................................................... 9 2.3 Line Commutated Converters ....................................................................................................... 9 2.3.1 Operation of Line Commutated Converters [3] .................................................................. 10 2.4 Veteran HVDC Topologies [3] [4] ................................................................................................ 14 Chapter 3: Modern and Future HVDC Transmission .................................................................................. 16 3.1 Insulated Gate Bipolar Transistors [11] ...................................................................................... 16 3.2 Voltage Source Converters [2] .................................................................................................... 16 3.2.1 Voltage Source Converter Installation ................................................................................ 17 3.2.2 Operation of Voltage Source Converters ............................................................................ 18 3.2.2.1 Multilevel Converters [2] ............................................................................................... 21 3.2.3 Modular Multilevel Converters [2]..................................................................................... 21 3.2.3.1 Operation of Modular Multilevel Converters ................................................................. 22 3.3 Applications ................................................................................................................................. 24 3.3.1 Interconnection of Intermittent Generation to a Weak AC System ................................... 24 3.3.2 Relieving Transmission System Congestion – Urban Infeeds ............................................. 25 3.3.3 Multi-terminal HVDC Systems and HVDC Transmission Networks ..................................... 26 Chapter 4: Examining Transmission Systems Considering HVDC............................................................... 30 4.1 Statement of Criteria .................................................................................................................. 30 4.2 Explanation of Criteria ................................................................................................................ 31 4.3 Applying Methodology to a System ............................................................................................ 33 4.4 Summary of Methodology .......................................................................................................... 51 4.5 PSS/E Simulations........................................................................................................................ 53 4.5.1 Description of PSS/E Model ................................................................................................ 53 4.5.2 Method for Simulating Converter Operation ..................................................................... 54 v Chapter 5: Conclusion ........................................................................................................................... 56 5.1 Future Work ................................................................................................................................ 56 5.1.1 Protection................................................................................................................................ 56 5.1.2 Mutual Coupling between DC Lines and AC Lines .................................................................