Fig.: The new hybrid battery system combines high-energy and high-performance cells and is a key component of the new concept for electric drive and energy systems for lorry trailers. © Fraunhofer LBF, 2024.
The joint research project >>evTrailer2<< has reached its second milestone: all of the project team's new technical ideas for the development and integration of high-efficiency technologies for electric drive and energy systems and for greater driving safety for heavy articulated lorries have been technically worked out. The next big step for the new electric traction concept is the assembly of these technical components into a semi-trailer, which can then be transported sustainably. This will help vehicle manufacturers to reduce the greenhouse gas emissions of new trucks by an average of 15 per cent by 2025 and 30 per cent by 2030 compared to 2019 levels.
In the joint research project ‘Electric drive cooperation and energy system for heavy commercial vehicles - evTrailer2’, a consortium from industry and science is working on making progress with regard to further CO2 reduction in heavy articulated lorries (N3, vehicles for transporting goods over twelve tonnes) and driving safety. The research group aims to achieve a new, previously unattained level of efficiency and further develop the concept of an electrically powered semi-trailer suitable for ‘traction cooperation’ with the tractor unit in such a way that the GHG reduction targets, i.e. minus 30 per cent for the period after 2030, can be achieved by the end of the project in 2025.
Hybrid battery system combines high-energy and high-performance cells
All of the consortium's ideas have been finalised since the beginning of 2024. Among other things, Fraunhofer LBF has developed a new hybrid battery system that combines high-energy and high-performance cells. This enables the battery system to continuously deliver and also absorb electricity at low power and briefly at high power. This allows the proportion of recuperable energy to be significantly increased, as high currents occur briefly when driving downhill, for example, which can be safely absorbed by the high-performance cells. With the hybrid battery storage system, high-energy and high-performance cells can be utilised in an ageing-friendly manner without compromising on energy output and absorption.
Intelligent operating strategy goes online to trailers
Researchers at the Institute for Internal Combustion Engines and Vehicle Drives (VKM) at TU Darmstadt have developed a cloud-based operating strategy to coordinate the various components and energy flows. The power requirement for a planned route is calculated on a server using a predictive approach and the operation of the trailer is optimised in terms of efficiency and driving behaviour. Possible breaks for intermediate charging of the battery are taken into account and planned in such a way as to maximise fuel savings. The system also ensures that the electrical energy available in the battery is fully utilised over the course of the route and is used in sections of the route where additional power is useful.
Trailer control unit and high-voltage box as central control unit
The application of the central control unit - Trailer Control Unit (TCU) - was developed by industry partner CuroCon using a new high-performance multicore safety control unit with the aim of achieving the greatest possible operational self-sufficiency and flexibility, optimising the driving safety of heavy articulated lorries and increasing the driving stability and safety of the articulated lorry through wheel-selective drive torque distribution (torque vectoring) on the electrically driven axle of the semitrailer.
In addition, the TCU, in conjunction with the newly created front wheel, will enable the trailer to manoeuvre independently on company premises, realise the control of electricity production in the trailer's energy system in conjunction with the photovoltaic system (PV) installed on the vehicle, implement the efficient use of available energy in conjunction with the new cloud-based operating strategy and, in conjunction with the new shiftable reduction gears, control the gear steps and the overrunning clutches.
>>evTrailer2<< in driving test operation on the road
All individual technical components are to be assembled and their interaction tested by the end of 2024. The newly constructed 3-axle semi-trailer with electric traction and energy storage for the cooperative drive support of conventional semi-trailers is expected to be ready for road tests towards the beginning of 2025.
Background and more current information on the project: »evTrailer«
Scientific contact:
Project management: Michael Wißbach, michael.wissbach@curocon.de
Dr. Benedict Götz, benedict.goetz@lbf.fraunhofer.de
Source: Press Release, Fraunhofer LBF, 07. 05.2024.
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