Wireless electric vehicle charging explained


The concept of electric car charging over wireless is the stuff of science-fiction. You pull into a parking space with your aerodynamic roadster and magnetic resonance conduction sends a stream of electricity to your vehicle as you munch on salty chips. Then, Doc Brown jumps out from behind a curtain.

But get this: Qualcomm is set to roll-out a limited trial in London during the second half of 2012. The technology, called Qualcomm Halo Wireless Electric Vehicle Charging (WEVC), is deep into development cycles and set to launch with Renault sometime in the next three to five years.

The main advantage is convenience. Electric charging is a bothersome process for most drivers. You have to park in a designated area, connect your vehicle to a charging station, and then wait several hours for the charge to take place.

Wireless electric car charging

Some newer vehicles, such as the Ford Focus Electric, do charge in a shorter period of time, but you still have to find a charging station or tap up the power at home before you head out for the day. Wireless charging would solve one of the primary headaches: the trouble of having to get out of the vehicle and make the connections for charging.

According to Dr. Anthony Thomson, the vice president of business development at Qualcomm (and the former CEO of HaloIPT before the Qualcomm acquisition), wireless charging is now reaching a more mature stage and could be debuting at your local filling station in the next few years.

How WEVC works

The technology doesn't use a flux capacitor. Instead, there's a charging pad installed in the parking stall that streams power using magnetic resonance conduction to a charge pad on the underside of the vehicle.

The technology relies on basic principles of physics: the magnetic field is created by increasing the wireless frequency from around 50-60 hertz up to 40,000 hertz.

"We've known since the 1830s with Michael Faraday that a strong current always creates a strong magnetic field," says Thomson. "By increasing the frequency we increase the magnetic field, and create a gap for the power delivery. This is like having two transformers with a lateral tolerance."

The gap between the pads is about 6-inches, he says. The driver would only need to pull within a designated area and not in an exact alignment with the pads.

wireless vehicle charging

The technology uses the same principles of wireless charging found today on charging pads made by Duracell and others, transferring power over a magnetic field. One purpose of the London trial is to help develop regulations and standards for WEVC that all companies will adhere to.

Proof of concept

For now, the test in London will be a proof of concept and to see how the wireless charging system could be deployed. For example, the company wants to find out how users react to the charging system and its basic operation, although there is no direct user involvement. The two pads create a connection on their own and the transfer occurs without the driver having to step out of the car.

As for safety concerns, Thomson says the magnetic field would detect a change in the induction system. For example, if someone placed a fork between the pads, the system would shut down. The system could detect any interference, including small animals crawling between the charging pads.

The London trial will take place in the Tech City region of East London. Qualcomm did not release the exact plans about how to participate or when the trial would be held in the second half of 2012.