Friday, August 9, 2013

BMW’s electric car to hit market



The new all-electric BMW i3 is a landmark in BMW’s mission to provide a completely sustainable, electric vehicle that stays true to its ultimate driving machine signature. 

The BMW i3 is the first product of the new BMW i sub-brand, and is a truly purpose-built electric car. It’s a new era for electro mobility at BMW.

The vehicle concept behind the BMW i3 was designed from the outset to incorporate an all-electric drive system. This has numerous advantages over “conversion” vehicles, in which the original combustion engine is swapped for an electric motor. 

The engineers can design whatever works best in terms of construction, dimensions and configuration of the electric-drive system’s components.
The car’s development is dictated by the characteristics designed into the car by the development team, and not by the constraints imposed by a pre-existing vehicle design. 

For example, the space in a conversion vehicle set aside for the fuel tank or exhaust system cannot be used. In the BMW i3 there is no need for this kind of compromise.

This leads to the architecture concept, which was purpose-built specifically for the BMW i3. It is comprised of two modules; the life module, and the drive module. 

Think of the Life Module as the passenger cabin, or greenhouse. It is the first-ever mass produced Carbon Fibre Reinforced Plastic (CFRP) passenger cell in the automotive business, and is a big factor in the cars efficiency. 

Carbon Fibre Reinforced Plastic is equally as strong as steel, while being 50% lighter and 30% lighter than aluminium.

The interior is made using high quality renewable sources and recycled materials. The BMW i3 has the next premium interior, which blends sustainable resources with a premium feel for the same interior quality as the BMW 5 Series Sedan. 25% of the plastics in the interior and 25% of the thermoplastic parts on the exterior are made from either recycled materials or renewable sources.

The BMW i3 will be able to travel 80 to 100 miles on a single charge. This can be increased by up to approximately 12% in ECO PRO mode, and by the same amount again in ECO PRO+ mode. It is able to recharge in only 3 hours with the use of a 220V Level 2, 32-amp J1772 charger. 

The ultimate-drive machine

BMW i3, the ultimate driving machine, features brake energy regeneration, which when the driver sets off the motor acts as a generator and converts the kinetic energy into electricity, which is fed back into the battery for a range gain. 

This Regeneration is speed-sensitive, which means that the car “coasts” for added efficiency at high speeds, and generates the strong braking effect at lower speeds.

The BMW i3’s accelerator pedal has a distinct “neutral” position. Rather than switching straight to energy Regeneration when the driver eases off the accelerator, the electric motor uses zero torque control to separate from the drive train and deploy only the available kinetic energy for propulsion.
In this mode, the BMW i3 cruises using virtually no energy at all. This is another way anticipatory driving can preserve energy and increase the car’s range.

The impressive electric motor, small turning circle of 32.3 feet -- a major benefit to driving in the city -- BMW’s near-perfect 50-50 weight distribution, precise electric power steering and the stable suspension set-up help to make the i3 as satisfying to drive as every other BMW.

To improve efficiency it has low rolling resistance, and the narrow section width is a key factor in the BMW i3’s super-tight turning radius.

Beyond the traditional immediacy of response offered by electric motors when pulling away, power development in the BMW i3 also remains unbroken through higher speeds. 

Power is sent to the rear wheels through a single-speed transmission, allowing the BMW i3 to accelerate with an uninterrupted flow of power up to its top speed.

City-friendly

The BMW i3 marks the introduction of a new type of megacity vehicle. Its small size allows it to easily manoeuver and park on city streets, while the car’s short front and rear overhangs make parking in tight spaces much easier. Its sharp turning radius and nimble handling is a perfect match for city driving. 

In the front, the slide-through experience allows the driver to slide through the car and exit on the passenger side, to avoid exiting into a busy city street. This is made possible because of the absence of the transmission tunnel. 

The coach doors make getting into and out of the car much more practical by eliminating the B pillar and creating one large opening to enter and exit.

Not having to fill up on gas is a big advantage while living in the city, due to the lack of gas stations. Since electricity is so readily available, recharging is possible almost anywhere, and practically gives the BMW i3 unlimited range due to being able to charge at any and every stop.

Emission-free driving is also a plus in the city. Cities are so congested with cars idling at red lights or stop and go traffic, so having a car that runs on electricity that doesn’t pollute is another way that the BMW i3 benefits the environment, and its owner.

On a similar note, the navigation system can take traffic conditions into consideration and help route around any areas of large congestion, which is a huge benefit when living in a city with a lot of traffic. It can help maximise efficiency and cut down commute times in order to save you time.

The same navigation system also remembers the owner’s driving style and can judge by that and the amount of charge left if a route is too long or if a recharge is necessary for the return journey.

Combining aluminium and plastic

The new drive module has also been carefully designed and structured with these exacting crash requirements in mind. 

Crash-active aluminium structures in the front and rear sections of the vehicle provide additional safety. In a front or rear-on collision, these absorb a large proportion of the energy generated. 

The battery, meanwhile, is mounted in the under-body section of the car to give it the best possible degree of protection. Statistically, this is the area that absorbs the least energy in the event of a crash, and the vehicle shows barely any deformation here as a result. 

Moreover, positioning the battery in the under-body allows the BMW Group development engineers to give the vehicle an ideal low centre of gravity, which makes it extremely agile and unlikely to roll over.

The high-voltage battery also benefits from the excellent deformation properties of the CFRP Life module. In the side crash test, the pole does not penetrate as far as the battery. The mix of materials used and the intelligent power distribution module ensure that the high-voltage battery is optimally protected even in the side-sill area.

All in all, the high-strength CFRP passenger cell teams up with the intelligent distribution of forces to lay the foundations for optimum occupant protection.

In the unfortunate situation that an accident occurs, Intelligent Emergency Call sends information like location, number of front-seat occupants, and even crash severity data to the Connected Drive Call Centre, which quickly informs the appropriate dispatch centre.

Lithium-ion batteries are safe even in the event of a fire

Safety is a key criterion in the development of the BMW i models. A range of systems and measures have been implemented in the vehicle, which ensure safety in normal operations and in the event of accidental fires.

 The high-voltage system is designed to cope with accidents beyond the legal requirements, with the high-voltage battery including features that ensure its safe reaction even in situations such as this.

The latest series of tests conducted concluded that electric and hybrid cars with lithium-ion drive system batteries are at least as safe as vehicles with conventional drive systems in the event of fire.

To ensure maximum safety in a crash scenario, the high-voltage battery is disconnected from the high-voltage system and the connected components discharged when the passenger restraint systems are triggered. 

This safely feature prevents the possibility of a short-circuit, which could lead to electric shocks or cause a fire.

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