48V Research Group

The 48V research group has various applied, third-party funded research and teaching projects which concentrate on the development of hybridisation solutions for commercial vehicles and extra-low-voltage traction drives for city motor cars. The research group moreover operates the FZ Micro-Mobility Laboratory which emerged from the MVI-BW project “TrottiElec”.

Although the high-voltage electrification of vehicles with traction battery voltages of several hundred volts allows hybrid or purely electric drive chains to achieve a considerable performance, it also has considerable disadvantages regarding costs, maintenance effort and safety. The 48V research group is therefore looking for technical solutions whereby extra-low-voltages below 100V and intrinsically safe electrochemical storage systems can be used to enhance the essential electrification potentials in individual transport, and for closed transport chains in the public transport system operating in the hilly metropolitan region of Stuttgart.

Background

Although the high-voltage electrification of vehicles with traction battery voltages of several hundred volts allows hybrid or purely electric drive chains to achieve a considerable performance, it also has considerable disadvantages regarding costs, maintenance effort and safety. The 48V research group is therefore looking for technical solutions whereby extra-low-voltages below 100V and intrinsically safe electrochemical storage systems can be used to enhance the main electrification potentials of future diesel-powered commercial vehicles, of private vehicles, and for closed transport chains in the public transport system operating in the hilly metropolitan region of Stuttgart.

48V traction drives for city vehicles

High-voltage electric and hybrid vehicles are not suitable for student projects and prototype work with the limited resources of a university of applied sciences. In combination with a gear-shift, light to medium-heavy passenger vehicles can be operated in the Stuttgart metropolitan region with 48V traction voltage as well, even though the traction power is restricted to less than 30 kW. To this end, an attractive "48VCityRoadster" test vehicle with an operating permit in accordance with the German Road Traffic Licensing Regulations (StVZO) was created, which can be used with a low threshold for applied research projects on drive train optimisation at extra-low-voltage and for student project work, is being set up.

Electrified BMW Z3 as 48VCityRoadster. Image Faculty Mobility and Technology

Component overview 48V conversion. Image Faculty Mobility and Technology

Engine compartment 48VCityRoadster after conversion. Photo Faculty Mobility and Technology

Automotive Engineering Micro-Mobility Laboratory

Folding, light, electrified and portable ultra-light vehicles for the “last mile” shift the modal split towards public transport and reduce the volume of traffic looking for a parking space in metropolitan regions with a hilly topography. Electrified folding scooters will not be approved in Germany in the foreseeable future so that the only alternative available in the medium term is the folding EPAC (Electrical Power Assisted Cycle), which is not yet commercially available as a really light and portable vehicle. Esslingen University of Applied Sciences has developed the lightest folding EPAC - 9.9 kg - which can be used even when you are wearing a suit and tie to cover distances of up to 8 km (“last five miles”) - in the Stuttgart metropolitan area as well.

The Automotive Engineering Micro-Mobility Laboratory operates 8 of these vehicles for student practicals and prototype work with (low-cost) model building components.