Tutorial Title: Power Converters for Resilient Bipolar DC Distribution Grids

The transition from a predominantly fossil fuel-based power generation towards renewable power sources, predominantly wind turbines and photovoltaic systems, inevitably leads towards an energy supply system that greatly depends on power electronics to feed the energy in the electrical grid. As all power electronic driven systems are intrinsically DC sources or loads, DC transmission and distribution systems become evident, not only because it is more efficient and cost effective, but also increases the ampacity of cables.

Similar to AC distribution grids, which are configured in single- or three-phase systems, the DC distribution grids can be configured in monopole or bipolar structures. Compared to monopole systems, bipolar DC distribution grids are with numerous benefits, e.g., multiple available voltage levels and resilience of power delivery in case of a wire failure. This tutorial will present recent advancements in power conversion technologies for bipolar LVDC and MVDC distribution systems. Several novel converter topologies of AC-DC and DC-DC converters for LVDC and MVDC applications will be addressed, which are inherently capable of bipolar operation. These topologies are based on the concept of topological integration of voltage balancers, which are required individually in classic approaches for maintaining voltage balance of bipolar DC grids. With such integration technique, bipolar operation capability of dc-link can be obtained with minimum costs and conversion losses.

Presenters’  Information

Shenghui Cui, Seoul National University

Shenghui Cui (Member, IEEE) received the B.S. degree from Tsinghua University, Beijing, China, in 2012, the M.S. degree from Seoul National University, Seoul, South Korea, in 2014, and the Dr.-Ing. degree with the highest distinction (summa cum laude) from RWTH Aachen University, Aachen, Germany, in 2019, all in electrical engineering.

Since September 2021, Dr. Cui is with Department of Electrical and Computer Engineering, Seoul National University, Seoul, South Korea as an assistant professor. His research interests include interaction of power systems and power converters, power converters in ac/dc utility applications, and applications of wide-band gap power devices.