INDUCTIVE CHARGING
56 // July 2019 // www.electrichybridvehicletechnology.com
RAPID ISN’T RATIONAL
A lot of attention in the EV market
is focused on rapid, plugged-in
charging, but how fast can you
recharge with wireless charging?
Volvo conducted research at
Flanders’ Drive Strategic Research
Center and managed to successfully
wirelessly recharge a Volvo C30
using a power output of 89kW
electric in just 2.5 hours.
“Technically, we can deliver rapid,
wireless charging and can go up to
100kW or even 200kW,” says Dr
Afshin Partovi, CEO of Mojo Mobility.
“But the question is how much are
people willing to pay for it?”
“EVs that are coming to market
now have 7kW on-board DC chargers
that you can just plug in at home,
so I don’t see people wanting to pay
a lot of money on phase three rapid
wireless chargers at home.”
And others are more dismissive
of the very concept of rapid charging
EVs. Alex Gruzen from WiTricity has
said in the past that trying to “recreate
“Technically, we can deliver wireless
charging up to 200kW… but how
much are people willing to pay for it?”
Dr Afshin Partovi, CEO, Mojo Mobility
Wireless, or inductive charging
has its roots in Faraday’s 1831
law of induction, which
simply put, describes the
process of how to induce
a current by introducing a coil into the
magnetic fi eld generated by a current
fl owing through a cable.
“While inductive is often used as a catchall
term for wireless charging, the technology
specifi cally at work in electric vehicle
charging is known as magnetic resonance,”
explains Alex Gruzen, CEO of WiTricity,
a Massachusetts-based technology company
that has licensed wireless charging technology
to a number of automakers.
Through magnetic resonance, power can be
transferred over distance and through surfaces
at power levels equivalent to plugging in.
“The technology for EVs has
been in development for over
a decade,” he admits. “But the
industry is fi nally picking up speed
and cars equipped with the
technology are beginning to
hit the streets.”
Gruzen claims that its WiTricity
technology is as e cient and as
fast as a conventional plug-in
system but, crucially, easier to use.
“It’s important not to apply
consumer smartphone wireless
charging assumptions to the EV technology.
There’s no loss in e ciency versus plug-in
when going wireless for EV charging,” he says.
The system developed by WiTricity, the
DRIVE 11, involves a wallbox connected to
a 240V power source and a charging pad on
the ground. A vehicle outfi tted
with a receiver is required
to park over the pad for
1. BMW’s Ground Pad
inductive charging
system, introduced in
May 2018
2. Inductive charging
development at the UK’s
Sprint Power lab
3. Ground Pad included
an on-board parking aid
camera to ensure perfect
vehicle alignment
the gasoline experience”
was a “silly arms race”.
“I wish the industry would stop
trying to recreate what they can’t
recreate, which is gas, and start
to embrace what’s really possible,
which is charging where you park,”
he argues.
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