Fill’er up – wirelessly
UBC R&D to boost EV appeal.
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university of British Columbia
The University of British Columbia bets convenience will help make electric power more popular.
Lorne Whitehead and his team of researchers at the University of British Columbia (UBC) believe they’ve found a way to recharge electric vehicles (EV) more simply – one that involves no wires – and are hoping to give the segment a much needed boost.
“It’s a fairly well known concept. It would be nice to not have to plug in electric cars; to drive up instead to a charger and have it happen automatically,” says Whitehead, a professor at UBC’s physics and astronomy faculties.
Making recharging easier might help boost slow EV sales – consumers are still at the tire-kicking stage.
Just ask Chevrolet. The General Motors (GM) brand’s fully electric Volt was introduced two years ago with lofty sales targets of 60,000 units. But a hefty $40,000 price-tag and high profile engine fires wilted consumer confidence and GM eventually cut sales expectations to 35,000 units. The automaker suspended production in the summer because of insufficient demand, and has since lowered sticker prices.
Chevrolet only managed to sell 275 Volts in 2011 out of GM’s total Canadian sales of almost 250,000, according to DesRosiers Automotive Consultants. Nissan fared worse, selling only 170 of its electric Leafs out of the almost 85,000 units in Canada, while Mitsubishi sold an insignificant 23 iMiEVs out of sales totaling more than 20,500 units.
But the automakers haven’t given up on electric alternatives. GM is confident it will have more than 500,000 electrified vehicles on the world’s roads by 2017. It has also introduced an electric version of its Chevrolet Spark compact that promises to outdistance rivals with a new range capability. And Nissan has a revamped, lighter Leaf, which includes a streamlined battery system expected to boost single-charge range to up to 228 kilometres (as long as you don’t use the air conditioning).
UBC’s research team is hoping to build consumer confidence in EVs.
The Natural Sciences and Engineering Council (NSERC) awarded the project $185,000 to fund the research and it’s part of the university’s Campus as a Living Laboratory initiative, a program designed to offer UBC faculty, students and industry partners use of the university’s physical plant to test and apply new technologies.
Wireless charging was originally developed for medical devices, such as an implanted pacemaker. Although the technology isn’t necessarily new, Whitehead’s team hopes enhancing it will boost the convenience factor of EVs.
“The convenience issue is a much bigger deal than you’d think,” he says. “People don’t want to have to plug-in and unplug their vehicle every time they need it – it’s the same reason there’s still full-serve gas stations.”
The UBC solution is expected to be cheaper, efficient and safer than resonant induction charging, which involves transmitting electric power between two copper coils across an air gap.
A copper coil at the bottom of the car is force-fed an alternating current from another copper coil inside a transmitter on the ground that’s powered by the grid.
Addressing safety concerns
Whitehead says the resonant solution works, but it requires high frequencies, which creates other issues.
“Operating at higher frequencies requires more expensive electronics,” he says. “The size of the coil is also an issue because it can be quite big.”
He says there are also safety concerns with resonant technology.
“If you’re dealing with a strong current at a high frequency, you’re creating an electric field that will induce currents elsewhere – including people,” he says. “There’s a worry about those fields radiating in space, which could be harmful.”
UBC’s solution, while very similar, uses a different technique that operates at frequencies 100 times lower. “Remote magnetic gears” or rotating base magnets driven by electricity from the grid power a second gear in the car that eliminates radio waves. The base gear remotely spins the in-car gear to generate the power needed to charge the battery.
“The coil is smaller than those in the induction process because it’s actually the magnet producing a current inside the receiver’s coil,” he says. “The field intensity can be high locally at the coil but there are no fields outside it; they drop off outside the unit.”
The process is essentially the opposite of resonant induction charging because the source of the field that produces the current in the coil is in the distance – in this case, the local magnet. They’re powered only by magnetic interaction.
“The most obvious difference is that we produce frequencies that are up to 300 times less, making the electronics much simpler,” he says. “There are essentially no electric fields because they’re housed inside the machine. It’s a more prudent, safer approach to the technology.”
The system is currently achieving a 4-inch gap, which is comparable to resonant induction options. The school is actively testing the technology on school grounds. Four electric utility vehicles have been outfitted with receivers at the university’s maintenance building, while four transmitters have been installed in parking spots. Whitehead says the tests have proven successful so far.
“At the end of every eight-hour shift, they line the trucks up with a marker – you want to be in that four- to six-inch gap – leave it overnight and its ready to go again the next morning,” he says. “A full charge takes about four hours.”
The onsite testing program is helping to provide the research team with valuable information that’s expected to help bring the technology to market.
“We’ve been able to take a research discovery to an advanced prototype stage, significantly de-risking the opportunity for commercial partners by proving out the technology in a variety of conditions in real-world use,” says Paul Cyr, senior technology transfer officer at UBC’s physical sciences faculty.
There’s no industry partners collaborating on the project yet, but Cyr is confident the university will soon introduce a start-up company to lead commercialization efforts. He’s also confident EVs will become a significant portion of the vehicle market as technologies and offerings improve, which is good news for the UBC team.
“We’re providing a convenient, safe and efficient charging solution that we believe will help increase the adoption rate of electric vehicles in both fleet and consumers segments,” says Cyr.
Full-serve gas stations beware.
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This article appears in the Nov/Dec 2012 edition of PLANT West