Liran Zheng “Power Electronics for a Net-Zero Energy Future”

Abstract:
One of the most significant challenges that human society faces is producing and distributing clean and affordable energy. Electricity and transportation sectors are dominant sectors for US greenhouse gas emissions and account for 25% and 27% of total emissions in 2020, respectively. To enable a net-zero energy future, renewable energy and energy storage need to be integrated into the electricity sector. A paradigm shift from fossil fuel to clean electricity as the energy source of land, sea, and air transportation is also necessary. Power electronics serve as the electronic interfaces between smart power grids and resources including renewable energy, energy storage, and electrified transportation. Recently, the advancement in wide-bandgap semiconductors ignited significant interests in emerging medium-voltage (MV) power electronics, especially solid-state transformers (SSTs). I will discuss my Ph.D. work on new current-source single-stage SST circuits and model-predictive priority-shifting control methods for new stacked low-inertia SSTs. The advantages include significantly reduced size, improved efficiency and reliability, and universality for different net-zero applications. Based on the proposed concepts and customized 3.3 kV silicon carbide reverse-blocking MOSFET modules, a 5 kV DC SST and a 7.2 kV AC SST have been built and tested for MV DC renewable-energy collector and MV AC electric vehicle fast-charging applications, respectively. It is the first time that current-source MV SSTs have been demonstrated and reported. My patents from this work have been licensed under the GridBlock startup company for transportation electrification products. Finally, I will discuss future research directions for a net-zero energy future.

Bio:
Liran Zheng received the B.S. degree in control engineering from Tsinghua University in 2016, and the M.S. and Ph.D. degrees with the Center for Distributed Energy in electrical and computer engineering from Georgia Institute of Technology in 2018 and 2022, respectively.

He previously held visiting positions with The University of Texas at Austin, the NSF ERC Center for Power Electronics Systems at Virginia Tech, the General Electric Global Research Center, and the Electric Power Research Institute. He received a second prize paper award in 2021 and a first prize paper award in 2022, both from the IEEE Industry Applications Society. He holds issued and pending patents commercialized by GridBlock, a startup company out of Georgia Tech, for transportation electrification products. His research interests include power electronics circuits and control, medium-voltage power electronics based on wide-bandgap devices, applications in electric transportation systems, renewable energy systems, and smart grids, and control of distributed energy resources.

Details

• Date: Tuesday, March 7
• Time: 10:00 am - 11:00 am
• Category: Special Seminar
• Location: Grier A 34-401A

Host

• Jeffrey Lang
• Email: chadcoll@mit.edu