Protection of Multi-Terminal High-Voltage DC Grids

Presenter: Maryam Saeedifard, Georgia Institute of Technology

Abstract: High Voltage Direct Current (HVDC) transmission is a long-standing technology with many installations around the world. Over the past few years, significant breakthroughs in the voltage-sourced converter technology, along with their attractive features, have made the HVDC technology even more promising in providing enhanced reliability and functionality and reducing cost and power losses. Concomitantly, significant changes in generation, transmission, and loads such as (i) integration and tapping renewable energy generation in remote areas, (ii) need for relocation or bypassing older conventional and/or nuclear power plants, (iii) increasing transmission capacity, and (iv) urbanization and the need to feed the large cities have emerged. These new trends have called for Multi-Terminal DC (MTDC) systems, which when embedded inside the Alternating Current (AC) grid, can enhance stability, reliability, and efficiency of the present power grid. The strategic importance of MVDC and HVDC grids is evidenced by the number of worldwide projects currently in their advanced planning stage, e.g., European “Supergrids” and the Baltic Sea project, along with several projects in China. Amid the optimism surrounding the benefits of MTDC grids, their protection against DC-side faults remains one of their major technical challenges. MTDC grid protection is far more difficult than AC grids, as DC fault phenomenon is more complex. The protection philosophy of the MTDC grids, nevertheless, is similar to the AC counterparts in the sense that both primary and backup protection schemes are required. Upon occurrence of a DC fault, the recently emerged hybrid DC circuit breakers (CBs) need to selectively and quickly isolate any faulty line without interrupting the entire system. However, incorporating such DC CBs into the MTDC grid adds another level of complexity as the DC short circuit current increases with commensurate increase in transient overvoltage. This presentation is focused on addressing the aforementioned challenges associated with several protection aspects of the MTDC grids. At the end, an overview of the speaker’s current research activities on utility-scale power electronics based on emerging wide-band-gap semiconductor devices will be also presented.

Speaker bio: Maryam Saeedifard received her PhD degree in electrical engineering from the University of Toronto in 2008. Since January 2014, she has been with the School of Electrical and Computer Engineering at Georgia Institute of Technology, where she is currently a professor and holds a Dean’s professorship. Prior to joining Georgia Tech, Saeedifard was an assistant professor at Purdue University (2010-2013) and a research scientist with the Power Electronic Systems Group, ABB Corporate Research Center, Switzerland (2007-2009). She is the recipient of the 8th Nagamori Awards from Nagamori Foundation in 2022, Roger Webb’s Outstanding Mid-Career Faculty Award from the School of Electrical and Computer Engineering at Georgia Tech in 2021, U.S. Clean Energy Education and Empowerment (C3E) Technology Research & Innovation Award from the Department of Energy in 2021, First Place Prize Paper Award from the IEEE Transactions on Power Electronics in 2022 and 2021, IEEE Region 3 Outstanding Engineer Award in 2019, Best Transactions Paper Award of the IEEE Transactions on Industrial Electronics in 2018 and 2016, IEEE J. David Irwin Early Career Award in 2018, U.S. National Academy of Engineering, Frontiers in Engineering in Education in 2012, U.S. National Academy of Engineering, Frontiers in Engineering in 2011, Excellence in Research Award from the Office of Vice President in Research at Purdue University in 2012 and 2011, and the IEEE Richard M. Bass Outstanding Young Power Electronic Engineer Award in 2010. She is an IEEE Fellow, and is currently serving as a co-editor-in-chief of IEEE Transactions  on Power Electronics. Her research interests include power electronics and its applications in terrestrial and mobile power systems.

Faculty Host: Mohammad Shadmand, shadmand@uic.edu