Invited Tutorial

Wireless Power Transfer – from Science Fiction to Reality

Dr. Chris Mi,

Distinguished Professor and Chair of the ECE Department


Over the past 100 years, scientists have been searching for solutions to realize wireless power transfer reliably and efficiently. Their goal? A tether-free world. It is only in the past ten years that this has become reality. With the help of semiconductor devices, electromagnetic materials, and microcomputers, we can now not only charge a cell phone wirelessly, but we can also charge an electric car, implanted medical devices, under water vehicles, industrial automation equipment, robots, and automatic guided vehicles, or a humongous electric ship without plugging it in. In this talk, Professor Chris Mi will look at how his work has made wireless power transfer cheaper, faster, safer, and more efficient, enabling cable-free conference rooms, battery-less drones, and factories populated by untethered robots and autonomous vehicles.

  Both capacitive and inductive wireless power transfer technologies have been investigated for various applications. Experiments have shown that tens or even hundreds of kilowatts of power can be transferred over 200 mm distance with an efficiency of 97% (DC-DC) or more, and an alignment tolerance of up to 300mm. In this presentation, we will first look at the basic principle of WPT. Then we will show that safety is still one of the major concerns of WPT system for both inductive and capacitive power transfer, especially for high-power applications. Then, we will discuss two unique topologies developed by the research group of Prof. Mi, including the double-sided LCC topology and the LCLC topology for capacitive wireless power transfer. Finally, we will show some case studies that involve electric aircraft, railway, ships, and road vehicles.

  Dr. Chris Mi is the Professor and Chair of the Department of Electrical and Computer Engineering at San Diego State University. He is a Fellow of IEEE (Institute of Electrical and Electronics Engineers) and SAE (Society of Automotive Engineers). He is also the Director of the US Department of Energy-funded Graduate Automotive Technology Education (GATE) Center for Electric Drive Transportation at SDSU. He was previously a faculty member at the University of Michigan-Dearborn from 2001 to 2015, and an Electrical Engineer with General Electric from 2000 to 2001. He also served as the CTO of 1Power Solutions from 2008 to 2011. Dr. Mi received his Ph. D from the University of Toronto, Canada, in 2001.

  Dr. Mi has published five books, 204 journal papers, 126 conference papers, and 25 issued and pending patents. He served as Editor-in-Chief, Area Editor, Guest Editor, and Associate Editor of multiple IEEE Transactions and international journals, as well as the General Chair of over ten IEEE international conferences. Dr. Mi has won numerous awards, including the “Distinguished Teaching Award” and “Distinguished Research Award” from the University of Michigan-Dearborn, IEEE Region 4 “Outstanding Engineer Award,” IEEE Southeastern Michigan Section “Outstanding Professional Award,” and SAE “Environmental Excellence in Transportation (E2T) Award.” He is the recipient of three Best Paper Awards from IEEE Transactions on Power Electronics and the 2017 ECCE Student Demonstration Award. In 2019, he received the Inaugural IEEE Power Electronics Emerging Technology Award. In 2022, he received the Albert W. Johnson Research Lectureship and named the Distinguished Professor, the highest honor given to a SDSU faculty member and only one award is given each year.

  Dr. Mi was the Chair (2008-2009) and Vice-Chair (2006-2007) of the IEEE Southeastern Michigan Section. Dr. Mi was the General Chair of the 5th IEEE Vehicle Power and Propulsion Conference, Area Editor of IEEE Transactions on Vehicular Technology, associate editor of IEEE Transactions on Power Electronics, Associate Editor of IEEE Transactions on Industry Applications. He is the topic chair for the 2011 IEEE International Future Energy Challenge and the General Chair for the 2013 IEEE International Future Energy Challenge. Dr. Chris Mi is a Distinguished Lecturer (DL) of the IEEE Vehicular Technology Society.

  He is Guest Editor-in-Chief of IEEE Journal of Emerging and Selected Topics in Power Electronics - Special Issue on WPT, Guest Co-Editor-in-Chief of IEEE Transactions on Power Electronics Special Issue on WPT, Guest Editor of IEEE Transactions on Industrial Electronics - Special Issue on dynamic wireless power transfer, and steering committee member of the IEEE Transportation Electrification Conference (ITEC- Asian). He is Program Chair or General Chair of a number of international conferences, including Workshop on Wireless Power Transfer (WoW), IEEE International Electric Vehicle Conference (IEVC), and IEEE International Transportation Electrification Conference – Asia-Pacific. He is the Guest Editor of a Special Issue of the Proceedings of the IEEE - Electric and Hybrid Vehicles.