Tesla and Chevrolet might have committed to mass-producing electric cars, but that doesn't mean everyone is ready to plug a battery-powered car into their garage every night. Depending on who you ask, wireless charging might just be the solution. Even if we can't quite expect every manhole or green lane to extend our range just yet, a team at Oak Ridge Laboratories believes it has come close to creating a wireless car charging system efficient enough to broaden the appeal of electric vehicles.
Oak Ridge's 20 kW wireless charger was created in collaboration with Toyota, Cisco, Evatran and Clemson University, and is reported to operate at 90 percent efficiency. Built around a unique architecture, the system features an inverter, isolation transformer, vehicle-side electronics and technologies to couple the individual parts together.
In keeping with the mass-market, consumer focus of the 3-year project, the researchers have focused on making its operation as simple as possible. Rather than relying on complex in-car electronics to manage the charge, Oak Ridge's system places a major emphasis on software-augmented radio communications to regulate power flow, which should make the leap to regular road use more reasonable.
Although you don't need to plug it in, the wireless system's 20 kW does look a bit weedy compared to the 120 kW offered by Tesla's Superchargers. So, to make sure the Oak Ridge wireless charging system isn't dismissed for being too slow, the team of researchers is already working on a 50 kW setup that, according to team leader Madhu Chinthavali, should be safe and fast.
"The high-frequency magnetic fields employed in power transfer across a large air gap are focused and shielded," Chinthavali said. "This means that magnetic fringe fields decrease rapidly to levels well below limits set by international standards, including inside the vehicle, to ensure personal safety."
The Oak Ridge project is, in part, aimed at meeting the US Department of Energy's challenge to make EVs as practical and affordable as petrol-powered cars by 2022. A video from the system's creators is below.
Source: Oak Ridge National Laboratories