US Researchers Make Electric Car Wireless Charging Breakthrough

Wireless charging is a familiar innovation available to non-Apple smartphone users, and it could soon on the way for electric vehicles.

The US Department of Energy’s Oak Ridge National Laboratory (ORNL) has successfully demonstrated an electric car charging system that is as effective as wired.

No Plug

The ORNL demonstrated a 20-kilowatt wireless charging system and it claimed to have achieved 90 percent efficiency at three times the rate of the plug-in systems commonly used for electric vehicles today.

The ORNL worked with industry partners to develop the tech, including the likes of Toyota, Cisco Systems, Evatran, and Clemson University International Center for Automotive Research.

The development could herald an important step forward for electric vehicles, as the removal of the need to plug in the car to charge it up (potentially on the go) would greatly increase its convenience.

“We have made tremendous progress from the lab proof-of-concept experiments a few years ago,” said Madhu Chinthavali, ORNL Power Electronics Team lead. “We have set a path forward that started with solid engineering, design, scale-up and integration into several Toyota vehicles. We now have a technology that is moving closer to being ready for the market.”

Essentially, the ORNL’s power electronics team achieved this world’s first 20-kilowatt wireless charging system for passenger cars by developing an architecture that included “an ORNL-built inverter, isolation transformer, vehicle-side electronics and coupling technologies in less than three years.”

The researchers integrated the single-converter system into an electric Toyota RAV4 equipped with an additional 10-kilowatt hour battery.

Looking forward, the researchers are targeting a 50-kilowatt wireless charging system, which would match the power levels of commercially available plug-in quick chargers.

But building a wireless charging system for an electric car does entail some safety issues.

“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.”

“Wireless power transfer is a paradigm shift in electric vehicle charging that offers the consumer an autonomous, safe, efficient and convenient option to plug-in charging,” said David Smith, vehicle systems program manager. “The technology demonstrated today is a stepping stone toward electrified roadways where vehicles could charge on the go.”

Wireless Charging

Nokia was one of the first smartphone makers to include wireless charging with its Lumia handsets, as the former handset manufacturer was long-standing champion of the technology.

Wireless charging has spread to other devices including Samsung kit, but even years later, wireless charging still remains unavailable for Apple iPhone users.

That said, earlier this year it was reported that Apple was working with companies in the US and Asia to develop a long-distance wireless charging system that could be ready in 2017.

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