Researchers at Oak Ridge National Laboratory (ORNL) have successfully demonstrated the first 270-kW wireless electric vehicle (EV) charging technology, setting a new world record. This achievement, a collaboration with the Volkswagen Group, was showcased on a Porsche Taycan EV, highlighting ORNL’s advancements in wireless charging capabilities.
Earlier this year, the Department of Energy’s institution set a record with a 100 kW wireless charger. The latest demonstration further solidifies ORNL’s position as a leader in EV charging innovation. “In the past three months, the ORNL vehicle power electronics and electric drives research teams have set impressive world records for wireless charging,” said Lee Slezak, DOE’s Vehicle Technologies Office technology manager for grid and charging infrastructures.
The Porsche Taycan, a light-duty passenger vehicle, presents challenges for conventional large and heavy wireless power transfer systems due to space, weight, and volume limitations. To overcome these challenges, ORNL developed a lightweight system using polyphase electromagnetic coupling coils, which are slightly over 19 inches in diameter and deliver high power density in a compact form.
The system’s distinctive coil design and geometry enable the transmission of exceptionally high power levels through rotating magnetic fields created by the coil phase windings. This technology allows for a 50 percent charge in just 10 minutes at over 95 percent efficiency, with a 4.75-inch gap between the coil and the ground.
Current research at ORNL focuses on developing wireless charging systems for light-duty cars capable of achieving up to 11 kW of power and 92 percent efficiency. Industry standards currently cover power levels up to 20 kW. The wireless power transmission technology includes protection mechanisms against short-circuiting, overheating, and exceeding voltage and current restrictions, ensuring safe power transfer even during power outages.
ORNL is also collaborating with Volkswagen on a polyphase system for residential charging applications and developing a lightweight enclosure design to improve mechanical, electrical, thermal, and magnetic performance. Omer Onar, ORNL’s leader of the Vehicle Power Electronics group and lead researcher on the Porsche demonstration, emphasized the importance of this technology for everyday commuting.
Over the past decade, ORNL has significantly advanced wireless charging technology. In 2016, they transferred 20 kilowatts to an SUV using their own inverter and coupling tech, and by 2018, they reached 120 kW in lab tests with conventional coils. The recent 100- and 270-kW tests mark the first applications of ORNL’s polyphase system on electric vehicles.
ORNL hopes that extending the range and simplifying the charging process will promote greater usage of EVs, especially for light-duty passenger cars.