Multi-terminal Direct-Current Grids


Book Description

A generic DC grid model that is compatible with the standard AC system stability model is presented and used to analyse the interaction between the DC grid and the host AC systems. A multi-terminal DC (MTDC) grid interconnecting multiple AC systems and offshore energy sources (e.g. wind farms) across the nations and continents would allow effective sharing of intermittent renewable resources and open market operation for secure and cost-effective supply of electricity. However, such DC grids are unprecedented with no operational experience. Despite lots of discussions and specific visions for setting up such MTDC grids particularly in Europe, none has yet been realized in practice due to two major technical barriers: Lack of proper understanding about the interaction between a MTDC grid and the surrounding AC systems. Commercial unavailability of efficient DC side fault current interruption technology for conventional voltage sourced converter systems This book addresses the first issue in details by presenting a comprehensive modeling, analysis and control design framework. Possible methodologies for autonomous power sharing and exchange of frequency support across a MTDC grid and their impact on overall stability is covered. An overview of the state-of-the-art, challenges and on-going research and development initiatives for DC side fault current interruption is also presented.







HVDC Grids


Book Description

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.




Planning and Control of Expandable Multi-Terminal VSC-HVDC Transmission Systems


Book Description

This book discusses novel methods for planning and coordinating converters when an existing point-to-point (PtP) HVDC link is expanded into a multi-terminal HVDC (MTDC) system. It demonstrates that expanding an existing PtP HVDC link is the best way to build an MTDC system, and is especially a better option than the build-from-scratch approach in cases where several voltage-sourced converter (VSC) HVDC links are already in operation. The book reports in detail on the approaches used to estimate the new steady-state operation limits of the expanded system and examines the factors influencing them, revealing new operation limits in the process. Further, the book explains how to coordinate the converters to stay within the limits after there has been a disturbance in the system. In closing, it describes the current DC grid control concept, including how to implement it in an MTDC system, and introduces a new DC grid control layer, the primary control interface (IFC).







HVDC Transmission


Book Description

HVDC is a critical solution to several major problems encountered when trying to maintain systemic links and quality in large-scale renewable energy environments. HDVC can resolve a number of issues, including voltage stability of AC power networks, reducing fault current, and optimal management of electric power, ensuring the technology will play an increasingly important role in the electric power industry. To address the pressing need for an up-to-date and comprehensive treatment of the subject, Kim, Sood, Jang, Lim and Lee have collaborated to produce this key text and reference. Combining classroom-tested materials from North America and Asia, HVDC Transmission compactly summarizes the latest research results, and includes the insights of experts from power systems, power electronics, and simulation backgrounds. The authors walk readers through basic theory and practical applications, while also providing the broader historical context and future development of HVDC technology. Presents case studies covering basic and advanced HVDC deployments headed by world-renowned experts Demonstrates how to design, analyze and maintain HVDC systems in the field Provides updates on new HVDC technologies, such as active power filters, PWM, VSC, and 800 KV systems Rounds out readers' understanding with chapters dedicated to the key areas of simulation and main circuit design Introduces wind power system interconnection with HVDC Arms readers with an understanding of future HVDC trends Balancing theoretical instruction with practical application, HVDC Transmission delivers comprehensive working knowledge to power utility engineers, power transmission researchers, and advanced undergraduates and postgraduates in power engineering programs. The book is also a useful reference to for engineers and students focused on closely related areas such as renewable energy and power system planning.




Modeling and Simulation of HVDC Transmission


Book Description

The development of large-scale renewable generation and load electrification call for highly efficient and flexible electric power integration, transmission and interconnection. High Voltage DC (HVDC) transmission technology has been recognized as the key technology for this scenario. HVDC transmissions, including both the line commutated converter (LCC) HVDC and voltage source converter (VSC) HVDC have played an important role in the modern electric power system. However, with the inclusion of power electronic devices, HVDC introduces the characteristics of nonlinearity and different timescales into the traditional electromechanical system and thus careful modeling and simulation of HVDC transmission are essential for power system design, commissioning, operation and maintenance.




Information Theory


Book Description

Information Theory: Coding Theorems for Discrete Memoryless Systems presents mathematical models that involve independent random variables with finite range. This three-chapter text specifically describes the characteristic phenomena of information theory. Chapter 1 deals with information measures in simple coding problems, with emphasis on some formal properties of Shannon's information and the non-block source coding. Chapter 2 describes the properties and practical aspects of the two-terminal systems. This chapter also examines the noisy channel coding problem, the computation of channel capacity, and the arbitrarily varying channels. Chapter 3 looks into the theory and practicality of multi-terminal systems. This book is intended primarily for graduate students and research workers in mathematics, electrical engineering, and computer science.