Fundamentally, they're building a transformer. Ignore the marketing hype
about magical new energy transfer modes. It only looks different because
they're using high frequency transformer designs (like switchmode power
supplies use), instead of older 60Hz transformer designs.
Engineers pretty much know how to build safe, low-leakage, 98% efficient
transformers. Thus, the technical parts of the job are pretty
straightforward. It can be safe, efficient, and have very low leakage as
long as the designer knows what he's doing, and the marketing people
don't have too strong an influence (compromising performance for the
sake of appearance or cost).
*All* isolated chargers use a transformer for isolation anyway. So all
they are doing is repackaging the transformer so half of it is external,
and half in the car. Done right, this can be a good thing. It could
improve safety and reduce the overall complexity of the charging system.
The transformer serves both for isolation and coupling power to the
vehicle, thus eliminating the connector.
Unfortunately, this does not seem to be the direction they are headed.
The methods being shown are *more* complicated, more expensive, and less
likely to become any kind of standard. Personally, I think inductive
charging is being "sold" on the basis of
- convenience (it assumes people are too lazy to plug anything in)
- fear-mongering safety (connectors are "dangerous")
- money (it's a way to make more money on chargers)
I have to wonder why someone doesn't concentrate on a connector system
that auto-connects. That is bound to be simpler, more efficient, and
cheaper than these inductive systems. Way back in the 1960's, Bob Rice
was charging his EV with a drive-on connector system. Two flat metal
springs stuck up from a sheet of plywood. He drove his EV onto it, and
the springs hit a pair of mating terminals under the car. Power from the
car turned on a contactor in the off-board charger, which applied power
to the terminals to charge it. Simple as dirt.
--
"If an idea is good, really good; the way to oppose it is not with
force, but with complexity and regulations."
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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