TAKES CONTROL - International Rectifier

POWER
ELECTRONICS
34
Want to avoid the world’s
energy crisis? Alex Lidow,
chief executive of International
Rectifier, says motion control
would make a good start
POWER
TAKES CONTROL
By Rebecca Pool
IMAGINE CUTTING 10% of
the
world’s energy consumption in a single
swipe. There’s no need to unearth
technological breakthroughs or spend
millions, yet alone billions, of pounds. The
technology exists and is just waiting for us to
embrace it. Sounds too good to be true,
doesn’t it? Well, not if you believe Alex Lidow,
chief executive of US power electronics
business, International Rectifier. According
to Lidow, inefficiencies in converting
between different forms of energy are adding
significantly to overall energy costs. And the
key contributor to these inefficiencies, Lidow
argues, is the continued use of wasteful and
technically primitive approaches to motor
speed control.
“Around 40% of all the energy we use is
electricity, and of this figure, just over half
goes into electric motors,” says Lidow.
“However, if you look at the way in which
we use these motors, the vast majority –
around 80% – are electromechanically
activated.”
IEE Review | June 2004 | www.iee.org/review

POWER
ELECTRONICS
Voltage Tolerance in (mV)
300
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200
150
100
50
0
Pentium II
Pentium III
di/dt
Tolerance
Pentium 4
Future
1997 1998 1999 2000 2001 2002 2003 2004 2005
Lidow argues that if, instead of using ‘all-on or alloff’
electromechanical drives to regulate motion, we
turned to variable speed drives, then energy
consumption levels would plummet. And this is where
our magic figure of 10% comes from.
“We could save half of all the motion control energy
if everybody converted to variable speed drives,” he
said. “So that’s half of [the energy consumed by
electric motors], or 25% of all our electricity, which
gives us a 10% saving on all the world’s energy.”
Indeed, in the US alone, an estimated £77.6bn a year
could be saved by switching to variable speed motion.
But if the gains are this great, why haven’t industries
taken on the technology in truck-loads? The answer
appears to lie in the low value we continue to place on
energy savings.
Lidow believes that if people are going to buy into
variable speed motion, it has to be very cheap or offer a
more tangible benefit. “We have to deliver variable
speed motion in such a way that its cost is offset by the
value delivered, excluding the energy savings,” he
explains. “Somebody has got to want to buy the
technology, not because it saves energy, but because it
does something else that is really cool.”
INVERTERS WASH WHITER
A key application area for variable speed motion
drives is appliances or ‘white goods’, including
washing machines, refrigerators and air-conditioning
units. The power electronics industry first started
taking real notice of variable motion control in the
900
800
700
600
500
400
300
200
100
0
di/dt (A/µs)
Above: Falling voltage
tolerances and shorter
current rise times have
stoked an increase in
the need for on-board
power management
chips in PCs
1990s. At this time, however, swapping, say,
a washing machine’s electromechanical
drive for a variable speed version, would
have cost thousands of pounds – clearly not
a realistic option. But despite the huge
expense, the manufacturers of washing
machines recognised that more
sophisticated motion control could
improve the functionality of their
products, enabling, for example, gentler
washing cycles and higher spin speeds –
qualities that consumers would actually
want.
Recognising the market’s potential,
International Rectifier embarked on a
mission to drive down the cost of motion
control. High voltage integrated circuits –
analogue and mixed signal – were
developed and new architectures
designed. Packaging, resistors, diodes and
software were all re-evaluated and
improved. And, eventually, the price-point
dropped from thousands to only tens of
pounds.
So today, says Lidow, manufacturers are
sitting back and watching sales of their
new generation of washing machines hit
the roof. The machines deliver energy
savings of around 60%, for ‘free’, which,
argues Lidow, is why consumers are
buying them.
“US analyst, Freedonia, forecasts that
26% of all washing machines bought in
2004 will have inverter [variable speed]
drives; it’s our fastest growing segment,”
he adds. And by 2013, Lidow expects to see
50% of the entire appliance market
converted to variable speed motors.
The good news for variable speed
motors doesn’t stop here. Lidow is
adamant that exactly the same principles
apply to the automotive industry. He
argues that by using exactly the same set of
technologies, cars could be manufactured
with twice the petrol mileage at no extra
cost and with no performance losses. Key
applications include integrated starter
alternators, hybrid engines and in-car
climate control. Over the next 25 years,
Lidow is confident that all energyconsuming
applications in cars will move
to variable speed drive control. ➔
35
IEE Review | June 2004 | www.iee.org/review

POWER
ELECTRONICS
37
ABOUT THE MAN
Alex Lidow graduated from the California Institute of Technology in 1975 with a B.S. degree in Applied Physics. He went on to study for a
PhD at Stanford University, during which time he says he “was aiming to make the most efficient field effect transistor”.
He joined International Rectifier in 1977 as a research and development engineer and went on to become vice president of research
and development. By the early nineties he had advanced to executive vice president of operations and was finally named chief executive
officer in 1995.
A co-inventor of the HEXFET – a power MOSFET architecture – Lidow holds nine patents in power semiconductor technology.
SETTING THE STANDARD
Use of a single common architecture is central to
International Rectifier’s strategy for increasing the
take-up of variable speed drives. “The volumes of
sales in IT are huge,” explains Lidow. “Around 100
million PCs are made every year, so you can support
quite a few microprocessor architectures with this
many sales.” This is clearly not the case for appliances
and cars, where volumes range from hundreds of
thousands to the low millions of units per year.
The answer, according to Lidow, is to design a small
number of reconfigurable architectures. “It could be
really easy to pluck out a digital signal processor used
in a mobile phone and make it work in a motor drive,”
he says. “But for each motor drive chip [design], you
can only expect a few million unit sales a year, so
standardising is very important in driving down the
cost of these specialised chips.”
Lidow sees additional benefits from standardisation.
First, many of today’s customers are not
specialised motor designers, but are, for example,
washing machine experts. Standardisation accelerates
the rate at which they can incorporate motor
drives into their products. Secondly, the automotive
industry – the other key market for variable speed
motor control – is risk-adverse and cost-sensitive and,
as such, is likely to welcome a common-architecture,
low-cost product that has been ‘road tested’ in the
harsh, humid conditions of a washing machine. “As
long as we adopt common architectures, we can learn
a lot from these experiences,” says Lidow.
BETTER AND BETTER
So what does the future hold for motion control and
indeed power management? Is this really going to
happen? Can we honestly expect to see the mass-uptake
of variable speed drives that power electronics
manufacturers are anticipating?
Analysts, across the board, are predicting revenue
growth in the semiconductor industry over the next two
years, which, if you do the maths, is actually good news
ABOUT THE COMPANY
for power management. Power dissipation
per unit area of silicon is on the rise,
implying a corresponding rise in demand
for power management.
Today’s PC, may, on the surface, look
similar to the PC of a decade ago, but as
clock rates have moved into the GHz range,
and variations in on-board voltage levels
have proliferated, power management
requirements have soared. The first
Pentium motherboards of the early 1990s
had a mere five chips dedicated to power
management. In today’s Prescott generation
motherboards, the corresponding
figure is, on average, 32. And the PC is just
the tip of the iceberg. There are household
appliances, automotive and communications
devices, all sharing a burgeoning need for
power management.
As Lidow says: “If you predict
electronics are going to do well, then you
will think semiconductors are going to do
well too. And if you think this, then you
will know that power management is going
to do even better.”
International Rectifier was founded by Lithuanian Eric Lidow in 1947,
father of Alex Lidow. Eric Lidow had studied engineering at the
Technical University of Berlin during the mid to late 1930s, but moved
over to the US in 1937.
Based in El Segundo, California, the company was first set up to
manufacture selenium rectifiers, but later moved towards the
development of discrete component products.
Now described as the world’s oldest independent semiconductor
company, Alex Lidow has driven the power management business
towards IT and communications, energy-efficient motion control,
defense and space systems and automotive applications.
IEE Review | June 2004 | www.iee.org/review