IEEE Power Electronics Magazine - June 2018 - 102

White Hot

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efficiency with power conversion densities well above 40 W/in³.
SiC has made great strides and is
now a viable choice for higher-power
or higher-voltage applications where
cost is not the main driver. In the
meantime, gallium nitride has quickly
been adopted for high-performance
switching applications in the middlevoltage range (200-900 V). The efficiencies being reported by leadingedge researchers-and products-in
the higher-power applications are so
high (99.3-99.7%) that measuring
them accurately is a real problem.
Both enabled and driven by the
advances in switching devices and
digitally enable advanced control,
power electronics applications have
sprouted and grown so rapidly we can
hardly keep up.
Electric propulsion has long been
used in rail transportation, such as
street cars and light rail systems. What
we often call a diesel locomotive uses
electric motors for driving the wheels.
But now we are seeing electric propulsion become practical in vehicles ranging from the family car to delivery
vehicles to full-size tractor trailers.
This move toward electric vehicles is
enabled by advances not only in battery technology but also in power electronics. The high-power electronics
used to drive electric motors and move
energy into and out of the batteries
today can operate at efficiencies well
above 90% with high reliability and
small size and weight.
We are also seeing power transmission within aircraft changing
from hydraulic to electric as the More
Electric Aircraft initiative advances.
Indeed, the Boing 787 Dreamliner
electric power system can deliver
more than a megawatt.
Combine electric propulsion with
electrically powered actuators, and
we have robots. Robotics is an area
that requires advanced power electronics. Yes, robots require advanced
processing of sensor information and
advanced control algorithms as well

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as optimized mechanical design, but
they also need advanced power conversion. From providing battery and
power management that optimizes
operation time to motor drives that
offer high power and speed at low
weight, power electronics is a crucial
part of all robotics. Today, when talking to students about careers in power
electronics, I often encourage them to
consider the opportunities in robotics.
Another application enabled by
power electronics developments, a
technology that was only a dream in
the year 2000, is wireless charging.
While not quite ubiquitous, in the coming years we can expect to see wireless
charging of our mobile electronics
everywhere, from our desktop to the
coffee shop to our hotel rooms. Wireless charging of vehicles is also
advancing. I personally have worked
on wireless charging of cars and transit buses. While admittedly not as efficient as directly wired chargers, the
convenience of wireless charging is
making this an attractive option.
In the last 20 years, we have seen a
huge growth of wind and solar power.
Both rely heavily on power electronics
to efficiently convert energy and interface with the grid. The growth of renewable energy and so much distributed
generation is upsetting the existing
power distribution infrastructure. For
more than a century, keeping the power
grid regulated and stable was done by
managing the power output of a few
central generating plants controlled
exclusively by the utility company. Now,
power is coming into the grid from
many sources, many of which have an
output that varies with the wind or
weather. How to manage the grid and
keep it stable under these conditions?
More advanced power electronics with
even more advanced control.
But after 20 years of power electronics advancement at such a dizzying pace, I again find myself thinking
like I did 20 years ago-that there is
not much new left for power electronics. I keep wondering what new power

z June 2018

electronic device technologies, packaging technologies, topologies, and
applications are next. Talking with
people at APEC, seeing the papers, and
roaming the exhibition hall only reinforced that feeling. Certainly there was
a great "buzz" and "energy" at APEC.
But all of the discussions focused
on improvements to existing devices,
architectures, and applications. It
leads me to think that we are in for a
period of time where we "digest"' the
rapid advancements of the past few
years and settle into a period where
these technologies fully mature.
But as soon as I catch myself thinking those thoughts, I hear alarm bells
in my head. I now know how I was
wrong 20 years ago when I was thinking that not much new was coming. So,
even though I keep looking around and
don't yet see the "next big new thing," I
also suspect that it is on its way and
will soon burst into view like a train
rocketing out of a tunnel. And I am
sure whatever is coming that I don't
see now will keep power electronics
an exciting and rewarding profession
for many more years to come.

About the Author
Robert V. White (bob.white@ieee
.org) has over 30 years of industry
experience as a power electronics engineer. He has worked in product design,
systems and applications engineering,
and technology development. He has
been an active volunteer with the IEEE
Power Electronics Society, serving several years on the Administrative Committee, two terms as technical vice
president, and as a Chapter chair. He
earned a B.S.E.E. degree from the Massachusetts Institute of Technology and
an M.S.E.E. degree from Worcester
Polytechnic Institute. He is currently
pursuing a Ph.D. degree in power electronics at the University of Colorado,
Boulder. Presently, he is the chief engineer of Embedded Power Labs, a
power electronics consulting company.
He is a Fellow of the IEEE.

Table of Contents for the Digital Edition of IEEE Power Electronics Magazine - June 2018