T3: State of the Art Technologies of Modular Multilevel Converters

10:40AM - 12:30PM
Monday, June 3rd, 2019

Sixing Du
University of Toronto, Canada



MMC is well recognized with the merits of modular design, scalable to very high voltage, and high reliability by means of redundancy, thus it is regarded as a promising approach for high-voltage and high-power applications. At present, MMC is extending to the applications of medium-voltage motor drives and high-power DC-DC conversions in addition to the regular high-voltage direct-current (HVDC) transmission. Various applications impose very different design constraints for MMCs due to the specific control objectives and performance regulations, leading to great technical challenges for MMC.

This tutorial will cover some of the cutting-edge technologies of MMC for coping with the newly emerging technical challenges in academia and industry. First, the conventional MMC, practical modulations, and typical controls will be illustrated for recalling the conventional MMC technology. And then, the emerging MMC topologies, operating principles, and circuit characteristics will be analyzed. Moreover, the technical requirements, challenges, and solutions of advanced MMC-based motor drives and applications in AC and DC power systems will be presented. Finally, the trends and future expectations of MMC topologies will be discussed.



Dr. Sixing Du received the Master and Ph.D. degrees in electrical engineering from Xi'an Jiaotong University (XJTU), Xi'an, China in 2011 and 2014, respectively. From 2015 to 2019, he has been a Postdoctoral Research Fellow in the Department of Electrical and Computer Engineering at Ryerson University, and University of Toronto, Respectively. He is going to join as a Distinguished Research Fellow in the School of Electrical Engineering, Xi'an Jiaotong University. His research includes high-power convers and their applications to medium-voltage motor drives and power systems. He has invented several novel MMC topologies for various industrial applications, which not only overcome the major technical issues of conventional MMCs at zero/low-speed operation in medium-voltage (MV) motor drives, but also achieve single-stage DC-DC conversion for HVDC and MVDC applications. Dr. Du has published 20 technical papers in peer-reviewed IEEE Transactions and other international journals as the first author with a total of over 500 citations in the past 6 years. He also published a Wiley-IEEE Press book "Modular Multilevel Converter: Analysis, Control and Applications" in January 2018 as a leading author. He holds 7 issued Chinese patents in power electronics, power quality, and High-voltage direct current transmission (HVDC) as co-inventor. Dr. Du received Excellent Doctoral Dissertation Award from Shaanxi Provincial Department of Education in 2017, and other prestigious awards in past few years.