Jinjun Liu  received the B.S. and Ph.D. degrees in electrical engineering from Xi’an Jiaotong University (XJTU), Xi’an, China, in 1992 and 1997, respectively. He then joined the XJTU Electrical Engineering School as a faculty.

From late 1999 to early 2002, he was with the Center for Power Electronics Systems, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA, as a Visiting Scholar. In late 2002, he was promoted to a Full Professor and then the Head of the Power Electronics and Renewable Energy Center at XJTU. He is currently a XJTU Distinguished Professor of Power Electronics. His research interests include modeling, control, and design methods for power converters and electronified power systems, power quality control and utility applications of power electronics, and micro-grids for sustainable energy and distributed generation.

Dr. Liu received for many times governmental awards at national level or provincial/ministerial level for scientific research/teaching achievements. He also received the 2006 Delta Scholar Award, the 2014 Chang Jiang Scholar Award, the 2014 Outstanding Sci-Tech Worker of the Nation Award, the 2016 State Council Special Subsidy Award, the IEEE Transactions on Power Electronics 2016 and 2021 Prize Paper Awards, the Nomination Award for the Grand Prize of 2020 Bao Steel Outstanding Teacher Award, and the 2022 Fok Ying Tung Education and Teaching Award. He served as an Associate Editor for the IEEE TRANSACTIONS ON POWER ELECTRONICS since 2006, 2015-2019 Executive Vice President and 2020-2021 Vice President of IEEE PELS, and was elevated IEEE Fellow in 2018. He was the Vice President for International Affairs, China Power Supply Society (CPSS) from 2013 to 2021, and since 2016, the inaugural Editor-in-Chief of CPSS Transactions on Power Electronics and Applications. He was elected the President of CPSS in Nov. 2021. Since 2013, he has been serving as the Vice Chair of the Chinese National Steering Committee for College Electric Power Engineering Programs.

Advanced Control of DER Interfacing Converters Enabling Fully Autonomous Microgrid

Microgrid will be one of the major forms of distribution network for future power systems wherever there are abundant distributed energy resources (DER) in local area, to reduce power losses on the transmission lines and improve the reliability of energy supply. The control and operation of a microgrid has to ensure the system voltage to be within a nominal magnitude/frequency range and adequate output power sharing among all these energy sources, and at the same time to guarantee fast and smooth transfer of the microgrid operation between islanded mode and grid-connected mode. This is very often required to be realized through fully autonomous control where each source converter or the transfer switch is controlled by its own without getting or sensing any information remotely or from others so that a higher reliability and an easy-to-implement plug-and-play feature could be achieved. The requirement for a fully autonomous grid-organizing framework has been well fulfilled and has made a significant benefit for today’s power systems, but will be a really critical challenge for future’s more electronic power systems with microgrid being a possible form. The state-of-art autonomous control of DER interfacing converters for the coordination of bus voltage and power sharing in steady-state will be presented and summarized in this lecture. A whole-new concept device, Flexible Transfer Converter (FTC), is proposed to enable the fully-autonomous control of a microgrid for the transferring between two different operation modes. Through the FTC, the interfacing power between the micro-grid and the large grid can also be continuously adjusted by dispatching commands from system controller if necessary while the speed and smoothness of the transfer can be dramatically improved.