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ers can operate 5-20 times faster, depending on the
inverter switch type.
Faster inverter switching speeds have two main
benefits. The first is that faster speeds allow a reduction
in the size of DC link capacitors, which are expensive
and heavy parts of an EV powertrain inverter. Though
they’re still necessary, they can be much smaller, which
saves space, weight, and about $50 to $100. The second
benefit is that higher switching speeds produce cleaner
AC outputs. The faster the switching, the closer the out-
put wave is to a pure sine wave.
“Nothing’s more efficient than a pure sine wave,” Re-
nouard said. “But to develop the pure sine wave is very
expensive. You can do it today, but it requires huge out-
put filters that are heavy and very expensive. With our
way, by switching very fast, we can now make the output
so clean that you don’t really need an output filter, and if
you do, it will be very small and low-cost.”
The higher-quality sine wave produced by the faster-
switching inverter ultimately translates to a more effi-
cient electric motor. And a more efficient motor gets you
what every EV manufacturer strives for: more miles to a
charge. Pre-Switch says its technology can enable EVs to
obtain five to twelve percent more range.The Holy Grail for power electronics
The technology behind Pre-Switch began its life in
the hands of an audiophile robotics engineer who wasBy switching very fast, we
can now make the output
so clean that you don’t
really need an output filter,
and if you do, it will be
very small and low-cost.
THE TECH