A new invention by the Oak Ridge Laboratory is almost as efficient as high-speed chargers and paves the way for dynamic charging while in motion.
For the first time ever, scientists at the Oak Ridge Laboratory have came up with a 120-kilowatt wireless technology that charges batteries at 97 percent efficiency over a 6-inch gap.
At this point, the lab claims, the new wireless charger is almost as efficient as the high speed wired chargers that Tesla uses for its cars.
The new technology is a crucial step toward the researchers’ ultimate goal: create a 300- to 400-kilowatt wireless charger that fully charges electric vehicles in 15 minutes or less — which would be an even more incredible development.
The Oak Ridge charger is a new version of the world’s first 20-kilowatt wireless charger. The just-announced technology uses a new coil design that uses silicon carbide, according to the national laboratory.
Here is how it works: the coil gets energy from the electric grid and converts it to a high-frequency alternating current to generate a strong magnetic field capable of reaching another coil inside the car across a 6-inch gap. Then, the coil in the car does the reverse process but converting the field to direct current and feeding the batteries.
The charger is extremely compact and lightweight, according to project lead Veda Galigekere, who works at the Power Eletronics and Electric Machinery Group at Oak Ridge: “It was important to maintain the same or smaller footprint as the previous demonstration to encourage commercial adoption,” he said. According to Galigekere, the system doesn’t heat up or pose any safety issues, one of the basic development requirements.
Researchers want to turn this static charging method into dynamic charging. In other words, allow the car to recharge while driving on the road, using pads embedded inside the asphalt. According to Galigekere, the team hopes to pull this feat off at highway speeds.
It is the stuff of sci-fi novels, but it seems the team is advancing fast toward the holy grail of electric vehicle charging.
Image Credits: Oak Ridge Laboratory/DOE