Tutorial Title: Advanced Modulation and Dynamic Control of Dual-Active-Bridge Based Intelligent DC Substation in Flexible Electrical Networks

This talk provides an in-depth discussion and advanced knowledge of modulation and dynamic control of high-power three-phase dual-active bridge (DAB3) dc-dc converters to enhance the operating performance and functionalities of intelligent dc substations in dc-grid applications. With the increasing integration of renewable energies, energy storage systems and the emerging fast charging stations for electric vehicles, dc distributions grids present numerous advantages e.g. higher efficiency, higher power capability and higher flexibility compared to existing ac grids. The key enabling component of flexible dc grids is the intelligent dc substation based on high-power dc-dc converters, which needs to achieve high efficiency over a wide voltage and power range, control the power flow and grid voltage dynamically, and ride through dc short-circuit faults. By employing the asymmetrical duty cycle control method, the soft-switching range of the DAB3 converter is significantly extended over a wide voltage range with a reduced RMS current especially in light-load conditions. Thereafter, this talk also introduces an elegant method to control the transformer winding current and magnetizing flux of the DAB3 converter instantaneously and simultaneously under transient conditions. Thereby, the dc substation can control the power flow dynamically without causing transformer core saturation. Finally, a dc fault ride-through method for the DAB3 converter is explained, which enables the breakerless protection of dc grids. The tutorial will conclude with a Q&A session.

Presenters’  Information

Jingxin Hu, Nanjing University of Aeronautics and Astronautics

Dr. Jingxin Hu is currently a Full Professor at Nanjing University of Aeronautics and Astronautics (NUAA). He received B.S. degree from Northeastern University, China, in 2010, and the M.Sc. degree and Dr.-Ing. degree with summa cum laude from RWTH Aachen University, Germany, in 2013 and 2019, all in electrical engineering. Before joining NUAA in 2022, he was with ABB Corporate Research Center (Switzerland) in 2012 and General Electric Global Research Center (Germany) from 2013-2014. From 2014 to 2022, he was a Senior Scientist and Research Associate at E.ON Energy Research Center, RWTH Aachen. Dr. Hu was the recipient of Prize Paper Award of IEEE IPEC ECCE Asia in 2018. the STAWAG Best Dissertation Prize of RWTH Aachen University in 2019, and IEEE TPEL Outstanding Reviewer Award in 2021. He serves as an Associate Editor for Journal of Power Supply, Technical Program Committee Co-Chair of eGrid 2020, and Session Chairs of IEEE ECCE Asia, PEDG, CIEEC and ISIE. His main research interests include high power converters, intelligent energy routers, renewable power generation and energy storage, as well as dc transmission and distribution.