New wireless EV charging record set by experimental Porsche

Wireless charging for electric vehicles (EVs) remains an aspiration rather than a reality for most. While a few startups have introduced commercial solutions, these offerings are not particularly user-friendly, with charging speeds that seldom exceed 11 kilowatts.

However, a significant breakthrough might be on the horizon. A modified Porsche Taycan, provided by Volkswagen Group of America to the Department of Energy’s Oak Ridge National Laboratory (ORNL), recently set a new record for the fastest wireless charging session on a light-duty passenger vehicle.

This achievement was made possible by a novel polyphase wireless charging system, which was seamlessly integrated into the underbody of the electric vehicle (EV). The researchers at ORNL succeeded in transferring a peak power of 270 kW to the Porsche Taycan, matching the car’s maximum direct current (DC) charging rate. It is important to note that this experiment was conducted on a previous-generation Taycan, not the latest model that supports up to 320 kW from a compatible charger.

The system developed by ORNL utilises lightweight electromagnetic coupling coils with a diameter of just over 19 inches. These coils allow for higher power density within a compact size. The lab explained that the technology is similar to the wireless charging systems found in consumer electronics such as smartphones. However, the key difference lies in the polyphase coils used in the Taycan, which feature rotating magnetic fields generated by the coil phase windings, boosting power to unprecedented levels.

Omer Onar, leader of the Vehicle Power Electronics group at ORNL and the lead researcher on the Porsche project, stated: “The receiver coil designed for the Porsche Taycan research vehicle can achieve 8 to 10 times higher power density compared to existing systems. Per kilowatt weight, this is also the most lightweight charging system in the world.”

The distance between the ground-based sender unit and the receiver on the car was 4.85 inches, and the system achieved an efficiency of 95%. This means that the wireless charger developed by ORNL could increase the Taycan’s state of charge by 50% in just 10 minutes, comparable to the speed of a DC cable connection.

This is not the first time ORNL has set records with its wireless charging technology. In 2016, the lab achieved a wireless transfer rate of 20 kW on a Toyota RAV4 equipped with an additional 10-kilowatt-hour battery. More recently, in 2022, a charging speed of 120 kW was recorded with a Hyundai Kona.

As for when the public might see fast, wireless charging for EVs become widely available, it is still uncertain. The 270 kW demonstration marked the conclusion of a DOE-funded project initiated by ORNL and Volkswagen in 2021. Nonetheless, there is still hope. The research lab and Volkswagen plan to continue their collaboration, aiming to refine the system, making it smaller, more cost-effective, and easier to manufacture at scale.