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Ongoing field tests involving more
than 600 MINI E cars, including 450 in the US, have already
provided vital knowledge about the demands on future
electrically powered production vehicles. Beginning in 2011 in
the US, Europe and China, a test fleet of over 1000 BMW ActiveE
vehicles, produced at BMW’s Leipzig plant, will provide further
valuable insights into the everyday use of the vehicle. The
findings will serve to deepen the knowledge already gained on
the everyday use of electric vehicles and to learn more about
customer requirements. The feedback from customers testing the
MINI E and the BMW ActiveE will be fed directly into series
production of the MCV, which the BMW Group will be launching
under a new sub-brand in 2013.
With the BMW ActiveE, the BMW
Group is extending field tests on electric mobility and is
intensifying research into electric mobility in everyday
driving. For this reason, the drive components and battery
technology that will be used in the MCV are being tested on the
BMW ActiveE. The knowledge gained will be fed directly into
series development of the MCV. With the BMW ActiveE, the future
of individual mobility combining driving pleasure with zero
tailpipe emissions is one step closer.
Electric mobility as a supporting
pillar of the EfficientDynamics development strategy
In the development of
groundbreaking vehicle concepts and drive technologies within
the framework of the EfficientDynamics strategy, the BMW Group
attaches key importance to electric mobility. With
EfficientDynamics the BMW Group has for been very successful in
reducing fuel consumption and emission levels through new and
highly-efficient engine generations, enhancement of
aerodynamics, the use of innovative lightweight construction and
intelligent engine management - all with better performance in
the bargain. Thanks to EfficientDynamics, the company is now
able to achieve additional economy advantages through the
further electrification of the drive train and hybrid
technology. In the medium term, the BMW Group is developing
vehicle concepts for emission-free mobility in larger urban
areas. In the long term, EfficientDynamics means the transition
to emission-free mobility - using both battery power and
sustainably produced hydrogen.
On the way to sustainable,
CO2-free mobility, the BMW ActiveE represents the next major
milestone. Following the MINI E, the BMW ActiveE is the BMW
Group’s second electric vehicle made available to consumers.
With output of 170 horsepower and maximum torque of 184 lb-ft,
the car accelerates from 0 to 60 mph in under nine seconds
(preliminary), demonstrating the dynamic characteristics typical
of a BMW. At the same time, newly developed lithium-ion
batteries facilitate a vehicle range of around 100 miles in
everyday driving.
Just like the MINI E, the BMW
ActiveE is a conversion car, an electric vehicle based on the
body and chassis of an existing car. The BMW ActiveE integrates
all-electric drive components such as batteries, electric motor
and power electronics in a vehicle body that was not originally
intended for this purpose - and without significant compromise
on space or interior comfort. Therefore, the BMW ActiveE is the
BMW Group’s first electric vehicle to offer four fully-fledged
seats and a seven cu-ft luggage compartment. The BMW ActiveE
incorporates a pilot series version of the same drive train and
batteries Planned for the MCV.
BMW eDrive - the BMW ActiveE’s
control display concept
The instrument cluster and the
control system were specifically adapted to the electric drive
concept of the BMW ActiveE. In place of a tachometer, the
instrument on the right of the cluster shows the amount of
energy being taken from the battery or the current amount being
supplied to it through recuperation. When the vehicle is at a
standstill, the needle in the middle position indicates that the
vehicle is ready to drive, as the BMW ActiveE has no engine
sound to inform the driver whether or not it is ready to drive.
If the vehicle is not ready, the needle rests at the bottom left
of the instrument. The “fuel gauge” below it indicates the
battery charge level. Furthermore, the onboard computer provides
additional vital information such as the remaining vehicle
range, for example.
The eDrive display functions on
the Central Information Display depict vehicle energy flow.
During the journey an active schematic representation of the
vehicle informs the driver whether energy is currently being
taken from the battery or being fed into it through
recuperation. Moreover, the driver can see the current charge
state of the battery and also check whether the air conditioning
or the heating system is currently in use. This representation
can, if required, also be shown as a split screen to allow the
simultaneous display of additional infotainment contents or the
route guidance of the navigation system. When the vehicle is at
a standstill, it is also possible to see on the display whether
the vehicle is currently being charged or whether the battery
and interior are being climatically conditioned. In addition, a
special battery information menu provides information on the
battery energy level as well as the current and remaining
vehicle range. During charging it also indicates the remaining
charging time.
Optimum comfort, optimum
efficiency - the ECO PRO Mode
If the driver wishes to increase
the range of the BMW ActiveE even further, it is now possible to
do this via the ECO PRO Mode. As soon as the driver activates
the switch on the center console, the vehicle’s drive
configuration and comfort functions are modified to facilitate
an even more efficient driving style. The accelerator pedal
mapping program delivers less power in the ECO PRO Mode than in
the normal driving mode, but with the same pedal travel. The
heating and air conditioning systems have a flatter setting and
therefore use less energy. The driver is also provided with tips
on how to reduce energy consumption even further for the best
possible driving efficiency.
Emission-free, powerful and
compact: the drive system of the BMW ActiveE
The BMW ActiveE represents typical
BMW driving pleasure in a new, emission-free form. The heart of
the BMW ActiveE is the powerful electric synchronous motor.
Maximum power output of the electric drive system is 170
horsepower while maximum torque of 184 lb-ft is available from a
standstill, as is typical of electric vehicles and it remains
available across an exceptionally broad load range. As a result,
the BMW ActiveE accelerates from 0 to 60 mph in under nine
seconds. Top speed is electronically limited at around 90 mph.
The permanent-magnet synchronous
motor and the power electronics of the BMW ActiveE were
developed entirely in-house and are characterized in this
combination by exceptional efficiency, optimized power
development and a compact design. The innovative character of
the electric drive system is reflected above all in the relation
between engine output and space requirement. The entire power
pack including power electronics and transmission with
differential is integrated into the modified rear-axle support
of the BMW ActiveE, and with 170 horsepower, still has a total
weight of only around 200 lbs.
Brake Energy Regeneration: drive
and slow down with the accelerator pedal
The driving experience of the BMW
ActiveE is enhanced by the possibility of slowing down using the
accelerator pedal via brake energy regeneration. When the driver
lifts off the accelerator pedal, the electric motor becomes a
generator that feeds the electricity gained from kinetic energy
back into the vehicle battery. At the same time, braking torque
is created, which effectively slows the vehicle down. In this
way, the accelerator pedal becomes a “drive pedal”. In urban
traffic around 75 percent of all deceleration can be
accomplished without using the brake pedal at all. Intensive use
of this recuperation of energy via the motor also results in a
range increase of up to 20 percent. Only when the driver wishes
to slow down faster by stepping on the brake pedal does the
conventional braking system of the BMW ActiveE come into play.
Gliding - “coasting” along the
road
Unlike the MINI E, the BMW ActiveE
features a distinctive “intermediate position” of the
accelerator pedal, allowing the vehicle to “glide”. As a result,
the vehicle does not immediately recuperate when the driver
decelerates, but “de-clutches” using the electric motor’s zero
momentum control, thereby utilizing its own kinetic energy to
move forward. The BMW ActiveE then “glides” along the road
without using energy. Gliding offers a most convenient way of
increasing the vehicle’s range.
Lithium-ion batteries with liquid
cooling system
Specially developed lithium-ion
storage cells ensure the energy supply of the drive system and
all further functions of the BMW ActiveE. These high-voltage
battery units are exceptional for their high storage capacity.
The BMW ActiveE features large-format storage cells, which are
being used for the first time and were jointly developed by the
BMW Group and its associate partner SB LiMotive exclusively for
automotive use.
With the BMW ActiveE developers
are testing the storage cells and the storage electronics, which
are to be installed later in the MCV. Combined into modules of
six, eight or ten storage cells, they fit perfectly into the
available space in the BMW ActiveE. The large battery unit of
the BMW ActiveE takes up the space in the lower area of the
vehicle normally intended for the drivetrain in a conventional
vehicle. In order to accommodate additional storage cells, the
space at the rear that has become available through the omission
of a fuel tank is also utilized. Further lithium-ion cells are
located at the front end in front of the cowl.
The BMW ActiveE’s three large
storage modules are each protected by a specially-constructed
steel-plate battery housing with integrated liquid cooling
system. The cooling system constantly maintains the ideal
operating temperature of the batteries, thereby contributing to
an increase in the service capability and lifespan of the
battery cells. The air conditioning/heating system tempers the
liquid running through the storage unit housing via a heat
exchanger. When connected to the electrical grid, the liquid can
also be heated in order to bring the energy storage units up to
the ideal temperature of approximately 70° Fahrenheit.
Thanks to these measures, the BMW
ActiveE achieves a range of approximately 100 miles with a full
battery charge. Intelligent battery management especially
developed for the BMW ActiveE ensures that this range can be
achieved as far as possible independent of external climatic
conditions.
Fast and flexible recharging
The development of electrically
driven series production vehicles also encompasses innovative
solutions for flexible, convenient and user-friendly charging of
the vehicle’s batteries. The lithium-ion battery units featured
in the BMW ActiveE can be recharged from multiple external power
sources. In addition to using the wallbox, a 32-ampere charging
dock installed at the user’s home, the driver can also connect
the vehicle to a conventional power socket or a publicly
accessible charging station. The standardized SAE J1772 charging
port on the vehicle ensures compatibility with most charging
stations.
The battery can be fully charged
within four to five hours using the wallbox at 32 amperes. A
range of around 25 miles is possible after just a one-hour
charge at the wallbox.
The power electronics - greater
efficiency, enhanced development of power
The BMW ActiveE’s power
electronics developed by BMW have been designed to get the
maximum potential out of the electric motor. As in the future
MCV, the BMW ActiveE’s power electronics are located above the
rear axle on the electric motor, forming a complete unit
together with the motor.
Apart from controlling the
electric motor, the power electronics also ensure the power
supply to the onboard electrical systems. With the aid of a
voltage transformer and incorporating intelligent battery
management, they ensure the reliable supply of electricity to
all vehicle functions including the comfort and infotainment
features. Central control functions, which are integrated into
both the power electronics as well as the energy storage system,
constantly monitor all components.
Superior and comfortable - typical
BMW, even with regard to handling
On the road, the BMW ActiveE
offers the typical BMW driving experience offering the handling
characteristics and performance of a BMW 1 Series Coupe. The
positioning of the batteries lowers the vehicle’s center of
gravity. Moreover, the flexible distribution of the storage
units facilitates the 50:50 weight distribution typical of BMW
automobiles.
In addition to the adaptation of
the rear axle to accommodate the electric drive, the BMW
ActiveE’s suspension-related modifications are mainly restricted
to specific components. For example, steering characteristics,
springs and shock absorbers are adapted to the higher weight
compared to the production version of the BMW 1 Series in order
to reproduce typical BMW handling in combination with the
electric drive train. The suspension setting was chosen with a
special focus on comfortable and superior driving in cities and
the urban environment for which the BMW ActiveE is predominantly
designed.
BMW ConnectedDrive remote
functions for the BMW ActiveE
With BMW MyRemote, BMW enables the
user to access the extensive range of BMW ConnectedDrive
functions via an app for the Apple iPhone (from 3G) and the iPad.
The user has at his or her disposal all BMW ConnectedDrive
remote functions using the CE device such as locking and
unlocking the doors, the activation of the horn or headlamp
flasher for locating the vehicle within sighting or hearing
range, the CarFinder for locating the car within a radius of up
to 3,300 feet as well as the Google Local Search function.
In addition, new remote functions
developed especially for the BMW ActiveE for battery charge
control and vehicle preconditioning have been incorporated into
the range of functions. Via the customer’s Connected Drive
Account the iPhone application establishes a unique connection
with the vehicle and automatically displays the additional range
of functions as soon as the Connected Drive Account has been
identified. However, prerequisite for all remote functions is
that both the vehicle and the user are receiving a signal. Of
course, the driver has access to the BMW ConnectedDrive
functions without using an iPhone. This serves solely as a
remote control and information device.
eCommand: charge level, range and
preconditioning at a glance
The specific electric car
functions, called eCommand, comprise both charge control and
control of the preconditioning of both the batteries and the
interior cabin. The charge control function allows the user to
start and stop the charging process as well as the setting of a
charge timer. Via charge control the user can view the charge
level at any time and see whether the vehicle is currently being
charged. Users are informed of the battery charge level (State
of Charge), the vehicle’s current travel range with a full
battery charge and the time remaining until the batteries are
fully charged. Another display function informs users how far
away they are from work or the destination that has been
predefined as their home, so that they are able to make a best
possible estimation of the distance they are still able to
travel. Moreover, the app informs users where the nearest
battery charging stations are, offering the opportunity to send
these directly to the navigation system’s routing function as an
interim destination.
Preconditioning for enhanced
vehicle range
Unlike the MINI E, the BMW ActiveE
offers the user the potential to cool or heat both the batteries
and the car interior using intelligent preconditioning when the
vehicle is connected to the grid, thus bringing them up to the
ideal operating temperature even before setting off. A
preconditioned vehicle offers two advantages: first, the ideal
operating temperature of the batteries guarantee highest
possible power output and ensure a longer range. Secondly, the
interior is already adjusted to a pleasant temperature prior to
starting a journey - both in the summer and the winter.
Intelligent preconditioning of the BMW ActiveE automatically
determines according to the ambient temperature to what extent
the vehicle and the battery should be pre-cooled or heated.
Using the BMW MyRemote
application, preconditioning can be activated directly or the
user can determine via the timer when preconditioning should
start. For instance, he or she can ensure that the vehicle is
pre-cooled or heated in the mornings before they use the car.
However, it is only possible to precondition the car if it is
connected to a charging terminal. This ensures that the
vehicle’s range is not shortened by preconditioning, on the
contrary, it actually increases it. Due to the heating and
cooling process while the vehicle is connected to the power
supply, the energy required for this is no longer drawn from the
battery during the journey. Charging and preconditioning
functions are, of course, also directly accessible and
controllable from inside the vehicle.
BMW ActiveE arrives in the US this
fall
The BMW ActiveE is scheduled to
make its North American debut this April at the New York
International Auto Show. It will be available for lease on a
limited basis beginning this fall in the metropolitan markets of
Los Angeles, San Diego, San Francisco, Sacramento, New York and
Boston as well as the state of Connecticut.
Photos: BMW
(February 10, 2011)
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