Interviews

In this interview, Sheldon answers questions from his webinar, Wireless Charging For Autonomous Electrified Micro-Mobility Devices:  A Real-World Solution For Smart Cities To Be Pandemic-Ready, originally presented on June 30, 2020.

SheldonSheldon S. Williamson (S’01–M’06–SM’13–F’20) received his Bachelors of Engineering (B.E.) degree in Electrical Engineering with high distinction from the University of Mumbai, Mumbai, India, in 1999. He received the Masters of Science (M.S.) degree in 2002, and the Doctor of Philosophy (Ph.D.) degree (with Honors) in 2006, both in Electrical Engineering, from the Illinois Institute of Technology, Chicago, IL, specializing in automotive power electronics and motor drives, at the Grainger Power Electronics and Motor Drives Laboratory.  Currently, Dr. Williamson is a Professor at the Smart Transportation Electrification and Energy Research (STEER) group, within the Department of Electrical, Computer, and Software Engineering, at Ontario Tech University, in Oshawa, Ontario, Canada. He also holds the prestigious NSERC Canada Research Chair position in Electric Energy Storage Systems for Transportation Electrification. His main research interests include advanced power electronics and motor drives for transportation electrification, electric energy storage systems, and electric propulsion. Prof. Williamson is a Fellow of the IEEE.

Question: What is the range of frequency and power levels for the combined far field and near field solution?

The power level depends on the application. You can have anywhere between 3.7 kW to 11.0 kW today, as per SAE J2954 standards. Frequency ranges for far-field WPT could be between 2.4–5.8 GHz, while for near field, as per standards, the range is 85 kHz.

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In this interview, Sheldon answers questions from his webinar, Smart Battery Energy Management and Health Conscious Fast Charging for Future Transport, originally presented on June 2, 2020.

SheldonSheldon S. Williamson (S’01–M’06–SM’13–F’20) received his Bachelors of Engineering (B.E.) degree in Electrical Engineering with high distinction from the University of Mumbai, Mumbai, India, in 1999. He received the Masters of Science (M.S.) degree in 2002, and the Doctor of Philosophy (Ph.D.) degree (with Honors) in 2006, both in Electrical Engineering, from the Illinois Institute of Technology, Chicago, IL, specializing in automotive power electronics and motor drives, at the Grainger Power Electronics and Motor Drives Laboratory.  Currently, Dr. Williamson is a Professor at the Smart Transportation Electrification and Energy Research (STEER) group, within the Department of Electrical, Computer, and Software Engineering, at Ontario Tech University, in Oshawa, Ontario, Canada. He also holds the prestigious NSERC Canada Research Chair position in Electric Energy Storage Systems for Transportation Electrification. His main research interests include advanced power electronics and motor drives for transportation electrification, electric energy storage systems, and electric propulsion. Prof. Williamson is a Fellow of the IEEE.

Question: How does fast charging lead to reduced battery life?

DC Level-2 fast charging of 50 kW and above tends to cause capacity fade at a faster rate, which is mostly influenced by the growth of the solid electrolyte interphase (SEI) layer within the cells. This increases the cell’s internal resistance as well as the quantity of free lithium capable of cycling. The increase in SEI predominantly occurs with ambient temperature (Ta) above 25°C, which in turn, decreases calendar life of the cells (and the pack).

See: L. Patnaik, A. V. J. S. Praneeth and S. S. Williamson, "A Closed-Loop Constant-Temperature Constant-Voltage Charging Technique to Reduce Charge Time of Lithium-Ion Batteries," in IEEE Transactions on Industrial Electronics, vol. 66, no. 2, pp. 1059-1067, Feb. 2019.

Click here to read the complete interview. 


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