17 November 2012

New wireless charging concept by British Columbia University

The researcher at the University of British Columbia (UBC) Physics department has come up with the novel wireless electric vehicle charging concept. Inspired by the method for magnetically driven charger for medical application such as the pacemaker, the concept has been extended to the electric vehicle charging, albeit still in the proof of concept stage.

The current state of the art wireless charger plays around with electromagnetic induction principle whereby the varying electric current in the transmitter resonates with the similarly varying current in the receiver creating the current flow recharging the battery. The drawback of such system is that is could radiate heat to the nearby metal or emit radio waves, both could raise the safety concern for the public, definitely won't be a help in mitigating the sceptism  about electric vehicle.

The UBC concept is wholy different in a sense that it utilizes a remote magnetic gears which relies on the magnet dynamic coupling whereby, even with the lack of contact, the two magnetic gears are rotated harmoniously simply by the interaction of the magnetic field between the two. Where the magnetic gear on the transmitter side is motorized, the rotated gear on the receiver side will drive the generator that produce the electricity to recharge the battery.

To demonstrate the concept, UBC researchers has build a trolley demonstrator which house the magnetic drive. As can be seen on the right the bottom bar on the your left is the transmitter which housed the rotating magnetic gear. When the magnetic gear rotate, due to magnetic interaction, the magnetic gear on the receiver side will turn too, generating electricity to power up the bulb at the back of this trolley.

For the field demonstrator, UBC has fitted such system to their service vehicles. Four wireless charger station has been build and the charging to their EV achieved 90% more efficient than the cable counterpart. They also found that the perfect alignment between the transmitter and receiver is not needed to achieve the desired virtual mechanical coupling.

While the system is still in its infancy, due to the immaturity of this technology, the potential can still be considered as high. Admittedly, to produce the system for mass application there is still a lot of refinement needed. First is the packaging. At the moment the magnetic gears are separated from the driven motor and the generator driven by mechanical gears, whereas for production these could be designed to be integrated. The material for the magnetic gears also is still lab-staged and a cheaper, easier to manufacture replacement need to be found.

The video demonstrating UBC wireless charger can be found after the jump.

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