lDate and Time: June 21, 2023 (Wednesday) 9:30 AM to 11:30 AM

lPresentation Venue: Small Lecture Hall, Second Floor, Academic Conference Center

lSpeaker:Prof. Jian Sun

lAffiliation:Rensselaer Polytechnic Institute, USA

lHosted by: School of Electrical Engineering and Automation

Presentation 1：Generalized Immittance-Based Stability Criteria

lPresentation Overview:

An immittance-based stability criterion for grid-connected converters was published in 2011 to address emerging stability challenges associated with renewable generation and high-voltage dc (HVDC) transmission. The method attracted broad interests when the predicted new stability problems started to affect the industry in large scale in 2014-2015. Since then, immittance analysis has become a common practice in industry to support new renewable energy and HVDC product design and system development. New immittance-based specifications and grid codes are also being developed.

As the society moves towards carbon-free electricity that relies 100% on renewables, the power grid will also evolve into a converter-based power system. Converter-related stability challenges that so far have been limited to the grid interface of individual converters are expected to become more systemic and will require more general modeling and analysis methods. This talk will review stability challenges in future converter-based power systems and present generalized stability criteria based on immittance modeling and analysis for such systems, including both ac and hybrid ac-dc grids.

Presentation 2：Data Center Power System Stability

lPresentation Overview:

Data centers have evolved from serving dedicated customers and functions to being the hub of a growing IT infrastructure that people, businesses and institutions in many parts of the world rely on for everyday life and operation. A modern data center employs an advanced power distribution system to ensure high reliability, efficiency and power quality. With >100 MW power consumption and virtually every watt of electricity processed by power converters at least 2-3 times, data centers have a very high concentration of power electronics, surpassing that of large wind and PV farms and approaching that of high-voltage dc (HVDC) converter stations. As the result, data center power systems are also prone to the type of instability and resonance problems that have confronted the renewable energy and HVDC industry in recent years. This talk reviews practical data center power system stability problems and presents practical solutions based on immittance modeling, analysis and design.

lPresenter's Biography:

Jian Sun joined the faculty at Rensselaer Polytechnic Institute(RPI) in 2002. where he is currently a Professor in the Department of Electrical, Computer and Systems Engineering. He is also Director of the Center for Future Energy Systems (CFES) funded by New York State government. His research interests are in the general area of power electronics and energy conversion. He is credited for creating the small-signal sequence immittance theory and leading/promoting its practical applications in different industries internationally.

Dr. Sun received his doctorate from University of Paderborn, Germany. Prior to joining the faculty at RPI, he spent five years at Rockwell Collins working on power electronics for aircraft power systems, and was a Post-Doc Fellow at Georgia Tech from 1996 to 1997. As Director of CFES, he is responsible for the strategic directions and development of the Center's research, industry collaboration, education, and outreach programs. His professional services to the power electronics community included serving as Editor-in-Chief of IEEE Power Electronics Letters from 2008 to 2014. Treasurer of IEEE Power Electronics Society (PELS) from 2013 to 2020, and as PELS Vice President of Conferences since 2021. He received IEEE PELS Modeling and Control Technical Achievements Award in 2013 and the R. David Middlebrook Outstanding Achievement Award in 2017. He is a Fellow of IEEE.