The DOE’s Oak Ridge National Laboratory (ORNL) has created a 120 kW wireless charging system with a mere six-inch air gap between the battery and coils. Tests have shown the experiment to be 97% efficient, rivaling wired high-power fast chargers.
Their previous demonstration was a much smaller 20 kW system currently being modified for several EV applications including delivery vehicle charging. ORNL has combined this technology with new coil designs and modern silicon carbide power electronic devices to create the most recent light and compact 120 kW system. The team’s next step includes 200 kW and 350 kW systems with better dynamic charging qualities. Their ultimate goal is 15-minute (or less) highway-speed dynamic charging, which can only be made possible with the efficiency inherent in 350 kW to 400 kW systems.
“We used finite element and circuit analyses to develop a novel co-optimization methodology, solving the issues of coil design while ensuring the system doesn’t heat up or pose any safety issues, and that any loss of power during the transfer is minimal,” says Project Lead Veda Galigekere.