The powertrains fitted to current-generation electric vehicles are largely similar to those found in standard vehicles: a (electric) motor uses a transmission system to drive two wheels. But this concept does not allow electric vehicles to make full use of all available options and is therefore insufficient. This is why the ‘ATEM – powertrain technologies for electromobility’ funding programme places its focus on advancements in powertrain technologies used within electromobility.
Automotive manufacturers, suppliers and research institutions are cooperating within the ‘MEHREN – multimotor electric vehicle with highest room, energy efficiency and uncompromising driving safety’ funding project to build and install a wheel hub drive in a test vehicle. Wheel hub drives have the potential to substantially increase driving dynamics and safety. The compact drive units also mean significantly smaller vehicles. But the wheel hub drives produced within the ‘MEHREN’ project still have mechanical brakes, as until now exclusively electric brakes have been considered insufficiently safe. However, work conducted within the ‘FuSy – increasing functional safety for permanent magnet synchronous machines in traction drives’ project has since solved this problem.
Our experts at the DLR Project Management Agency recognised the synergies and successfully brought together partners for the ‘MEHREN’ and ‘FuSy’ projects. Formerly operating as stand-alone projects, the two groups have now formed the network project ‘RaBBiT’ to jointly develop a wheel hub drive with purely electric brakes on the drive axle that satisfy all authorisation regulations for operation on public roads. Firstly, this has made wheel hub drives simpler, lighter and less expensive. Secondly, it has increased the vehicle range, as the brake energy can be used to charge the battery and heat the interior.