Charged EVs | EU consortium aims to fit a 22 kW bidirectional on-board charger in a 4-liter package
A European consortium led by Fraunhofer IZM is developing a 22-kilowatt on-board charger with a volume of 4 liters—a third of the 12-liter market average for comparable systems today—using monolithically integrated, bidirectional gallium nitride (GaN) semiconductors from Infineon. The work is part of the EU-funded HiPower 5.0 project, running from August 2025 through June 2028.
The enabling technology is the bidirectional GaN switch. Conventional OBC designs use separate semiconductors for forward and reverse current flow. The monolithic GaN component handles both directions in a single device, reducing component count and enabling circuit topologies that weren’t practical with silicon. Fraunhofer IZM demonstrated a non-bidirectional 22 kW OBC prototype at PCIM Europe 2024—HiPower 5.0 adds the bidirectional GaN capability and targets further efficiency and cost improvements.
Rather than optimizing individual components, multiple electronics are embedded directly into the circuit boards, shortening electrical paths, reducing parasitic losses and saving space. Fraunhofer IZM treats design decisions as a whole-system problem rather than a component-by-component exercise.
HiPower 5.0 brings together partners from 10 European nations: 2 OEMs, 21 tier-1 and tier-2 suppliers, 6 power electronics specialists, 10 universities and 7 research institutions. Notable participants include Infineon, Mercedes-Benz, Mahle, Valeo, Siemens, Vitesco Technologies, TDK Electronics and AVL. The project covers 6 use cases across automotive and marine shipping. Total funding is €33.7 million from the EU and member states, with €5.74 million from the German Federal Ministry of Research, Technology, and Space and €0.12 million from the Free State of Saxony.
Source: Fraunhofer IZM
