Scientists from the US Department of Energy reported a world record for wireless power transmission. The experimental system transferred a record 270 kW of power to the batteries of the Porsche Taycan electric car, charging them to 50% in just 10 minutes with losses of no more than 5%. With such a device, charging electric vehicles will become the simplest operation during snack time in the station cafeteria.
A coil that transmits power wirelessly. Image source: ORNL
The development of promising and powerful wireless charging stations is being carried out by the research team at the Oak Ridge National Laboratory (ORNL) of the US Department of Energy (DOE). The project’s stated goal is to achieve wireless charging of vehicle batteries in 15 minutes or less with a transmission power of 250–300 kW. ORNL scientists first provided wireless power with a power of 20 kW in 2016, and already in 2018 they transmitted 120 kW of energy to air-gap laboratories.
Researchers have developed an extremely efficient way to transmit energy wirelessly. Using special coils with a variable phase of the electromagnetic field, a rotating field is created. Due to this, an energy transmission efficiency of over 95% is achieved. In March of this year, a modified 100 kW unit was able to charge the battery of a Hyundai Kona electric vehicle in less than 20 minutes to 50% capacity through a 5-inch (12.7 cm) air gap with an efficiency of 96%.
Another refinement of the wireless charger prototype made it possible to transfer 270 kW of power to the Porsche Taycan electric car across an air gap of 4.75 inches (12 cm). Charging of the electric vehicle batteries reached 50% after 10 minutes with an efficiency of more than 95%. Together with Volkswagen, which provided the practical side of the experiment on a real electric car, ORNL scientists agreed to develop powerful wireless charging for residential premises.
It should be said that today industry standards allow the production and operation of wireless chargers with a power of no more than 20 kW. Therefore, the ORNL team is focused on creating a commercial wireless charger with a lower power—only 11 kW. Chargers with a power of up to 300 kW will not soon please the owners of electric vehicles, but someday they will provide simplicity, comfort and speed of service if your car’s batteries need to be filled with energy.