Protection Principle and Technology of the VSC-Based DC Grid

This book discusses key techniques of protection and fault ride-through in VSC-HVDC grids, including high-speed selective protection, DC fault current limitation, converter restarting, and DCCB reclosing strategies. It investigates how high-speed transient-variable-based protection can be used to improve grids’ acting sensitivity, acting reliability, and ability to withstand high transition resistance compared with traditional protection. In addition, it discusses the applicability of the pilot protections, including the current differential protection and travelign-wave based protection, in the dc grid, as well as the improved methods. Furthermore, it proposes several DC FCL topologies, which are suitable for DC grids. Lastly, in the context of overhead line application conditions, it explores converter restarting and DCCB reclosing strategies, which not only identify the fault property, but also limit the secondary damage to the system, improving the system’s operation security and reliability. As such, the book offers a comprehensive overview of original and advanced methods and techniques for the protection of VSC-HVDC grids.

Introduction.- Working Principle and Basis Control Strategy of the VSC-HVDC Grid.- DC Fault Characteristics of the VSC-HVDC System.- High-speed Single-ended DC Line Protection for the VSC-HVDC Grid.- High-speed Differential Protection for the VSC-HVDC Grid.- Traveling-wave based Direction Protection for the VSC-HVDC Grid.- DC Fault Current Limiting Technique based on the H-bridge Topology.- DC Fault Current Limiting Technique based on the Current Commutation.- Restart Control Strategy for the MMC-based HVDC System.- The DCCB Reclosing Strategy in VSC-HVDC Grid.

Bin Li received his B.Sc., M.Sc., and Ph.D. degrees in Electrical Engineering from Tianjin University, China, in 1999, 2002, and 2005, respectively. He was an Academic Visitor at the University of Manchester, UK, in 2006, and from 2008 to 2009, he worked on the design and application of protection relays with AREVA, UK. Currently, he is a Professor at the School of Electrical and Information Engineering, Tianjin University, China. His research interests include the protection and control of AC power systems and DC grids. He has published more than 100 journal papers. In addition, he has published 9 monographs and holds 32 invention patents. Currently he is an investigator of some on-going research projects in this area supported by National Natural Science Foundation of China and the industry.

Jiawei He received his B.Sc. and M.Sc. degrees in Electrical Engineering from Tianjin University, China, in 2014 and 2017, respectively, and is currently pursuing his Ph.D. at the same university. His research interests include the protection and control of flexible DC grids and DC fault current limiting. He has published 29 papers, including 16 SCI-indexed papers and 13 EI papers, on these topics.