Combined charging and drive unit
Fraunhofer IEE is developing a new type of power unit for the drive and grid connection of electric vehicles – including grid-forming properties to promote grid stability.
Modern electric vehicles rely on multiple converters, such as AC or DC chargers, drive converters, and DC-DC boosters for charging 800-volt vehicles at 400-volt charging stations. Traditionally, these components are installed separately in vehicles. To address this inefficiency, the Fraunhofer Institute for Energy Economics and Energy System Technology (IEE), in collaboration with partners, is working on the “CombiPower” project. This initiative aims to develop a modular and multifunctional charging and drive unit that integrates these converters into a single device, reducing size and improving efficiency.
Enhancing grid stability
The bidirectional design of this modular unit allows energy to flow back into the grid from the vehicle battery while offering additional grid stabilization through its grid-forming control. This technology extends the vehicle-to-X (V2X) functionality by incorporating grid-forming properties. These features enable:
• Vehicle-to-Grid+ (V2G+): Stabilizing or rebuilding the power grid.
• Vehicle-to-Home+ (V2H+): Operating households as stand-alone systems during power outages.
• Vehicle-to-Device: Direct power supply to devices from the vehicle battery.
Funding for prototype
The prototype for the multifunctional and bidirectional charging and drive unit – based on wide-bandgap semiconductors and active EMC filtering – is already being researched in the “CombiPower” project. “Our aim is to develop the prototype to technology maturity level 6 and test it in the operating environment accordingly,” says Gorodnichev.
The project is being funded by the German Federal Ministry for Economic Affairs and Climate Protection with a total of 4.19 million euros and is being supervised by the DLR Project Management Agency. The project partners include Vitesco Technologies GmbH as consortium leader, Bonn-Rhein-Sieg University of Applied Sciences and SUMIDA Components & Modules GmbH. ROHM Semiconductor GmbH is also involved as an associated partner. The project started at the end of 2023 and will run until September 2026.
www.iee.fraunhofer.de
Source: 50,2 Magazine for smart grids