Researchers at Oak Ridge National Laboratory (ORNL) reached a new milestone after wirelessly charging a light-duty passenger EV at 100 kW with 96% efficiency, reports Electrek.
Scientists at the US Department of Energy-funded ORNL were able to wirelessly charge a Hyundai Kona EV with technology that can increase battery life by 50% in under 20 minutes.
This was achieved through the use of polyphase electromagnetic coupling coils with rotating magnetic fields. Using electromagnetic fields, power was transferred over a five-inch air gap to the Hyundai EV. The process is similar to wireless charging seen in small consumer devices.
According to ORNL’s Omer Onar, the experiment marks the highest power density in the world seen in a wireless charging system for this type of vehicle. Though the researchers previously achieved a 120-kW charge using conventional coil technology, this experiment with polyphase coils can reach power densities 8-10 times higher.
Thanks to the compact and light design of the polyphase electromagnetic coupling coil, the smallest coils–having a diameter of just over 14 inches–can achieve the highest power density possible. It gains even more power from rotating magnetic fields created by the coil phase windings.
“This breakthrough achievement opens the door to fast and efficient wireless charging for passenger electric vehicles,” stated Onar.
