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Saab Automobile is taking its first
step towards developing an all-electric vehicle with the Saab 9-3 ePower.
Making its world premiere at the Paris
International Motor Show later this month, the Saab 9-3 ePower is the
prototype for a test fleet of 70 vehicles which will participate in
extensive field trials in Sweden early next year. This all-electric
family estate represents an important step forward for Saab’s pursuit of
delivering cleaner and sustainable mobility solutions.
The performance of the cars will be
evaluated under a variety of real-world driving conditions as part of
the development process for a purpose-built, electric Saab vehicle.
Targets to be verified include a projected driving range of
approximately 200 kilometers through the use of high-density energy
storage in lithium-ion battery cells.
The Saab ePower is the first electric
vehicle from Saab and is a result of a co-operation between Saab
Automobile, Boston Power (batteries), Electroengine in Sweden AB
(electric power trains), Innovatum (project management) and Power Circle
(Sweden’s electric power industry trade organization).
Mid-sized SportWagon with zero
emissions
The Saab 9-3 ePower is the first
all-electric car to offer its occupants the comfort, size and
practicality of a SportWagon. Saab engineers have integrated an
electrical architecture within the shape and dimensions of a
‘conventional’ 9-3 SportWagon.
Under the bonnet is a 184 hp electric
motor driving the front wheels through a single-speed transmission.
Instant torque enables zero to 62 mph acceleration in just 8.5 seconds,
together with a top speed of 93 mph.
The compact yet powerful 35.5 kWh
lithium-ion battery pack is accommodated in a modified floor-pan, in a
space occupied by the exhaust system and fuel tank on the standard 9-3
SportWagon. This allows for optimum weight distribution and excellent
driving dynamics similar to those of a standard SportWagon.
Inside the cabin, a conventional,
automatic-style gearshift lever provides selection of ‘drive’,
‘neutral’, ‘park’ and ‘reverse’. The rev-counter, fuel and turbo-boost
displays in the main instrument cluster are replaced by read-outs for
battery status, power consumption and driving range, all illuminated in
green. To optimize space, an electric park brake is fitted.
Electro-hydraulic power steering is
used and the cabin is equipped with full air- conditioning, via a
compressor powered by the battery pack. A separate 12-volt battery, for
the lights and cabin ancillaries, is also charged from the battery pack
via a current transformer
The operation of the vehicle’s
powertrain is controlled by a version of Saab’s own in-house Trionic 8
engine management system, with new software written for an electric
vehicle application.
Long driving range with
excellent durability
The Saab 9-3 ePower’s projected driving
range of approximately 124 miles pushes out the boundaries for current
EV performance. Key to its long range are battery cells which have an
energy storage density substantially greater than the best currently
used in EV applications. High energy density also contributes to a lower
battery weight.
The battery pack has a capacity of 35.5
kW/h and is designed to operate with full power in ambient temperatures
as low as -30ºC, at least 10ºC below the operating level of other
battery packs on the market today. Another key benefit is the use of
air, instead of liquid, cooling which contributes to lower cost and
further weight-saving in the pack’s design.
The pack is intended to support
re-charge cycles equivalent to 10 years average use. It can be fully
recharged from a domestic mains supply in three to six hours, depending
on depletion status. Charging times can be greatly reduced if the
voltage of the electrical feed is raised, as there is no limitation on
the battery’s input capacity.
Test driving experience is expected to
validate the performance of this advanced battery pack, which is
designed to operate reliably within a full depletion ‘buffer’ set at
only 12 percent of total capacity, a much lower operating margin than
used in the management of other packs.
Its lithium-ion battery cells are also
the first to receive a Nordic Ecolabel accreditation for their
environmental safety and sustainability, which includes manufacturing
processes.
The 9-3 ePower meets the high
crash-worthiness standards that Saab applies to all its vehicles. The
car’s power pack is located outside the occupant compartment in
non-deformable structural zones, well protected and encapsulated. The
battery management and monitoring system supports safe performance
during normal driving and in crash conditions.
Extensive user trials
Hundreds of drivers and their families
will be enlisted by Saab and its development partners during an
extensive test driving and evaluation programme involving a 70-strong
fleet of Saab 9-3 ePowers in central, west and eastern Sweden during
2011-12.
The Saab ePower project team in
Trollhättan will monitor the performance of the cars across a wide
variety of usage patterns and driving conditions. To log essential
component data, all vehicles will be equipped with aircraft-style, black
box recorders.
“This programme is designed to evaluate
the potential for developing a high- performance, zero-emission electric
vehicle and is an important next-step in the extension of our EcoPower
propulsion strategy,” says Mats Fägerhag, Executive Director, Vehicle
Engineering at Saab Automobile.
“This includes engine rightsizing,
which exploits Saab expertise in turbocharging, as well as the use of
alternative fuel, such as bio-ethanol through Saab BioPower technology.”
Jan Åke Jonsson, Saab Automobile’s CEO
adds: “By 2015, annual global sales of electric vehicles are expected to
reach 500,000 units and Saab is determined to be represented in this
important, growing segment.
“The 9-3 ePower programme is our first
step towards developing a potential production vehicle that will deliver
the sort of advanced performance our customers expect. We now look
forward to working with our technical partners in developing such a
product.” |
