|The Concept 5 Series ActiveHybrid Click to enlarge.|
Along with the world debut of the new BMW 5 Series Sedan (earlier post) at the 2010 Geneva Motor Show, BMW is also presenting the BMW Concept 5 Series ActiveHybrid—its first combination of a BMW straight-six with electric drive. Integration of BMW ActiveHybrid technology in the new 5 Series model reduces both fuel consumption and emissions by more than 10%.
The drive system featured in the BMW Concept 5 Series ActiveHybrid consists of a straight-six gasoline engine with TwinPower Turbo technology, eight-speed automatic transmission, and an electrical drive system developed specifically for this model fitted between the engine and transmission. An automatic clutch connects the gasoline engine and the electric motors.
Drawing its energy from a high-voltage battery at the back of the car, the electric motor develops maximum output of 40 kW.
The drivetrain technology featured in the BMW Concept 5 Series ActiveHybrid allows all-electric driving in city traffic. An Auto Start Stop function offers additional efficiency by consistently switching off the combustion engine when stopping at the traffic lights, a road junction, or in congested traffic.
The electric motor also offers a boost function, supporting the gasoline engine in generating particularly dynamic drive power for an even more sporting driving experience in the car. The 5 Series hybrid also uses the auxiliary climate control function already featured in the BMW ActiveHybrid 7.
The high-voltage battery developed for this specific concept is fitted within a high-strength special case near the rear axle of the BMW Concept 5 Series ActiveHybrid. This leads to an optimum position in terms of both safety and harmonious weight distribution. An integrated control unit permanently analyses the charge status of the high-voltage battery and controls both the battery charge process by way of Brake Energy Regeneration and the system cooling process.
Apart from the electric motor, the high-voltage battery also delivers electric power to the car’s on-board network. Among other things, this allows efficient operation of the car’s auxiliary climate control activated whenever required by a remote control function to cool down the car’s interior significantly even before starting the engine.
All electrical functions such as the audio system, climate control or navigation remaining fully available even with the combustion engine switched off in all-electric drive mode or by the start stop system.
Intelligent energy management. A high level of all-round networking allows the power electronics to provide intelligent energy management, tailoring the interaction of the two drive units to the driver’s requirements, and optimizing the operating strategy of the entire vehicle under all conditions.
A further feature of energy management in the BMW Concept 5 Series ActiveHybrid is the car’s ability to adjust its operating strategy not just to current, but also to upcoming driving conditions. To do this the power electronics from the start evaluate data indicating a possible change in exterior conditions or the driver’s wishes and prepare the components in the drivetrain as well as the car’s electronic system for a possible change in requirements.
To analyse driving conditions up front, the system uses data provided by engine and chassis management as well as the sensors in the driver assistance systems on board the car. Data saved in the navigation system on the route chosen by the driver likewise goes into the final calculation, enabling the system to forecast driving conditions on the route directly ahead. Then, proceeding from this analysis, the car is coordinated in advance and the optimum use of all systems serves to use the energy available with maximum efficiency.
Should the system determine, for example, that the highway ahead is about to lead downhill, the charge level of the high-voltage battery is intelligently controlled in advance to regain brake energy upfront with maximum efficiency.
Similarly, the high-voltage battery may be fully charged in good time before the driver reaches his destination, enabling the system to switch off the combustion engine at an early point and change to all-electric drive along the final stretch of road. Indeed, this forward-looking function is able to extend the cruising range on electric power by up to 30%.