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MAHLE to present highly efficient 48V electric vehicle concept at IAA: MEET

7 August 2017

MAHLE has developed a highly efficient 48-volt electric vehicle concept for urban mobility. “MEET” (MAHLE Efficient Electric Transport) will make its world debut at IAA Cars 2017 in Frankfurt/Germany in September. The modular design could be transferred to a wide range of platforms, MAHLE said.

The technical focus of MEET is on maximum energy efficiency. The meshing of different energy-saving technologies in the areas of the powertrain and thermal management increases efficiency and significantly enhances the cruising range of the vehicle—even and especially at low external temperatures.

Optimized for city driving, the vehicle, due to its low mass and the maximum speed of around 100 km/h (62 mph), only requires a modest amount of drive power. Based on extensive test drives on a typical city route under different conditions and with different drivers, MAHLE determined that the maximum power requirement was around 20 kW.

To support journeys at higher speeds, MAHLE—in its first step—selected a systems power output of 28 kW for its demonstrator vehicle. This enables using a voltage level of just 48 V. As the voltage level is below the threshold of 60 V, there is no need for cost-intensive protective measures against electrical hazards. Consequently, systems costs are considerably lower than for high-voltage applications with the same driving performance.

Furthermore, MAHLE is systematically exploiting areas of synergy. According to the company, all of the technologies employed can be carried over into large-scale production—thus generating further cost benefits through economies of scale.

The MAHLE IPM (Interior Permanent Magnet Synchronous Motor) traction drive is an extremely efficient combination of a synchronous motor with permanent magnets and integrated 48-volt electronics. The motor provides maximum efficiency and dynamics in a wide speed range. To begin with, the MEET demonstrator vehicle was equipped with a MAHLE drive unit consisting of two motors each with 14 kW of mechanical continuous output and 36 N·m of torque.

MAHLE_MEET Preview

At IAA the next evolutionary stage with 20 kW and 80 N·m per motor will be presented. The motors drive the rear wheels via a central transmission.

This solution combines several advantages:

  • The structure is modular and can be easily modified according to the application, for example for other performance levels.

  • The existing 48-volt architecture of hybrid vehicles allows for an easy and cost-effective integration, for example as a drive unit/electric axis or for an electric all-wheel system.

  • The functional safety is increased by means of redundancy in the electric powertrain.

  • Maneuverability and agility can be improved with torque vectoring functionality.

  • As a result of the wide speed range of the motors, a gearbox is not necessary; systems efficiency is increased through the elimination of switching losses.

August 7, 2017 in 48V, City car, Electric (Battery) | Permalink | Comments (9)

Comments

And absolutely no mention of range.......

Range? Well, perhaps 1500 km with a big fuel tank.

Range? Well, lets see..."Optimized for city driving" so I guess it depends on the size of the city you want to cross.

Axial MARS motors can give you 20 hp at 48 volts three phase. Put one on each wheel with a 2000 pound car and there you go.

Mahle builds automotive parts and does not build cars. They are big in pistons and other engine components. The range of a vehicle using their electric drive train components would depend on the size and weight of the car, the aerodynamic drag and the size of the battery pact.

The whole idea with mild hybrids is to have a lightweight electrical system, i.e. small motors and batteries. Thus the electric range will be limited to parking garages and similar operation. If you want long electric range, you chose a PHEV. For a mild hybrid, does it matter if the range is, let’s say, 1 or 2 km? Most of the driving will be covered by the combustion engine anyway and the substitution with electricity would be minimal, if we had a plug-in option, which normally is not the case. It does not make much sense either. Battery capacity will be determined by other parameters such as sufficient size for regenerative braking, acceleration, auxiliaries and the requirement for power. Batteries should be kept as small as possible, not only for weight reasons but also to limit incremental cost. If the electric drive system is too heavy, fuel consumption will be significantly penalized in hybrid drive mode. We can clearly see that for PHEVs, where we also have a “conventional” HEV to compare with. The main objective with a mild hybrid is to reduce fuel consumption. If you want to substitute fuel with electricity, there are other (and better) options.

I acknowledge that MAHLE, with the limitations of a 48V electric system, seem to have taken this concept to a higher level than before. However, others will follow and challenge. In a few years, this will become the mainstream technology in vehicles. It will provide almost similar fuel economy as a full hybrids but at a fraction of the cost and weight penalty.

As more examples of capacitors integrated to the battery management systems are brought to market regenerative braking 'caching' recovery becomes more efficient and less reliant on battery sizing.

Battery progress towards lighter weight and longer life expectancy beyond the current 8-20 year norm as well as the general concern over the worst of our polluting activities forces the necessary response that will support this type of transport solution.
With the modular open platform that allows a high level of customer choice that this will find a large market place seems a no brainer.

Of course there needs to be charging 'sic' support and the business model will not favour the established liquid fuel 'gas guzzler' model given the supporting industries which represent such a high percentage of the 'western economies' have so much invested will naturally try and distract and obfuscate to prolong that outdated model.

Once you define it as an "urban" vehicle, it all gets easy because you do not need great range or speed, just reasonable acceleration, looks and safety.
A question could be is it a 2 or 4 seat vehicle - it looks like a small 4 seater from the sketch.
It would make a very good 2nd car for many families or urbanites, IMO.

Nice to see an EV concept focused on technology and regulatory options and constraints rather than some bizarre body styling dreamed up by the industrial design summer intern.

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