Researchers at the Department of Energy’s Oak Ridge National Laboratory have successfully demonstrated the first 270-kW wireless power transfer to a light-duty electric vehicle. The demonstration used a Porsche Taycan and was conducted in collaboration with Volkswagen Group of America using the ORNL-developed polyphase wireless charging system.
The ORNL-invented system that transferred power to the Porsche uses lightweight polyphase electromagnetic coupling coils with a diameter just over 19 inches that allow for higher power density in the smallest coil possible. This process is similar to the wireless charging of small consumer devices, but the unique geometry and design of the polyphase coils enable the transfer of extremely high power levels using rotating magnetic fields generated by the coil phase windings to boost the power.
Power density is important in wireless charging because it indicates how much power the system can handle relative to its size. The goal is to achieve higher densities from smaller, more compact systems to improve overall efficiency and performance. ORNL’s system can achieve a 50% increase in state of charge within 10 minutes with more than 95% efficiency. The power transfer was conducted over a 4.75-inch gap between the ground and the coil mounted to the underside of the vehicle..
Onar said ORNL and Volkswagen plan to continue working together in the near term to further improve upon the 270-kW charging prototype by developing it into a more cost-effective and manufacturable system. Volkswagen Group officials visited ORNL to view the lab’s novel lightweight polyphase electromagnetic charging system, capable of transferring unprecedented power to electric vehicles. Credit: Carlos Jones/ORNL, U.S. Dept. of Energy