On the afternoon of June 27, the IEEE PELS DAY academic seminar was successfully held at the 217 Lecture Hall of the Department of Electrical Engineering and Applied Electronics (EEA). The event was hosted by the IEEE Power Electronics Society (PELS) Beijing Chapter and organized by the IEEE PELS Tsinghua University Student Chapter, with co-organizers including the IEEE PELS Beijing Jiaotong University Student Chapter, IEEE PELS North China Electric Power University Student Chapter, IEEE PELS North Industrial University Student Chapter, IEEE PELS Yanshan University Student Chapter, and the Tsinghua University Member Center of the Chinese Electrotechnical Society.

The seminar invited three distinguished guests to give academic reports: Professor Li Yunwei, Vice President of IEEE PELS; Professor Lu Zhen’gang, Senior Engineer at the China Electric Power Research Institute; and Professor Wang Xiongfei from EEA. The seminar was attended by over 40 faculty and students from Tsinghua University, North China Electric Power University, Beijing Institute of Technology, North Industrial University, and Beijing Jiaotong University. The seminar was chaired by Su Bowen, Vice President of the IEEE PELS Tsinghua University Student Chapter.

Sun Kai, Chairman Member Committee of IEEE PELS China, delivered the opening speech, introducing the origin of PELS DAY, the history of PELS in China, and its member services, and extended congratulations on the successful organization of the IEEE PELS DAY event.

Professor Yunwei Li began by presenting IEEE PELS products and publications, including journals and AI tools. He then delivered the keynote speech titled "More Resilient Electric Grids through AC/DC Microgrids." The presentation discussed the power grid architecture and challenges in AC/DC transmission and distribution scenarios; the advantages of electric vehicle charging stations with energy storage systems and residential AC/DC secondary distribution systems with photovoltaics and energy storage; the application of hybrid AC/DC microgrids in AI data centers; energy management methods for different devices in microgrids; and compared the benefits of AC/DC hybrid microgrids with traditional AC power grids.

Zhen’gang Lu, Chief Engineer at the Power Electronics Institute of the China Electric Power Research Institute, delivered a lecture titled "Key Power Electronics Technologies for Power Transmission and Distribution in New Power Systems."

The presentation first introduced power electronics technologies in transmission and distribution, followed by a discussion on the background and development of DC transmission technology, including LCC-SLCC-CLCC-HCC-VSC routes, principles for selecting technology routes in different scenarios, and key technologies and trends in DC networking. It also covered the background, overall technology spectrum, and latest advancements in flexible AC transmission technology.

Professor Xiongfei Wang gave a presentation titled "Frequency-Domain Passivity-Based Analysis of Grid-Converter Interactions."

He first introduced the basic concept of passivity and its application in grid-connected converters. He then explained the passivity index for multi-input multi-output systems and the criteria for assessing system stability using the passivity index, concluding with the design goal for grid-connected converters to achieve passivity across all frequencies.

Subsequently, Sun Ya, a doctoral student from EEA, shared her experience in applying for the IEEE PELS Graduate Studies Fellowship.

Throughout the seminar, there was lively academic exchange between faculty and students, and the atmosphere was vibrant.

Introduction to PELS DAY:

The IEEE Power Electronics Society (PELS) is the most influential professional organization for power electronics worldwide, with over 13,000 members. Founded on June 20, 1987, this date is also designated as PELS DAY. Each year, local chapters and student chapters around the world hold seminars, invited lectures, industrial visits, student presentations, competitions, and other celebratory activities to mark the occasion.