Revolutionising electric mobility with compact, efficient on-board chargers
As Europe strives to meet its ambitious climate goals, reducing emissions from road traffic – which accounts for 80 % of the transport sector’s 28 % share of total EU emissions – has become paramount. Electric vehicles are central to this transition, but their progress is currently hindered by limitations in on-board charger (OBC) technology. The EU-funded HiPower 5.0(opens in new window) project aims to overcome these barriers by developing next-generation OBCs that are smaller, more efficient and cost-effective.
From 12 litres to 4 litres
Built into electric vehicles, OBCs convert grid electricity into energy that is suitable for batteries. However, current OBCs face significant challenges as power demands increase. Conventional silicon-based technology struggles with efficiency losses, heat generation and bulky designs. High-power OBCs often require extensive cooling systems, making them unsuitable for smaller vehicles. HiPower 5.0 is addressing these issues by creating a groundbreaking 22-kW OBC that occupies just 4 litres of space – significantly smaller than the current market average of 12 litres. The project’s innovation lies in its use of gallium nitride (GaN) semiconductors provided by project partner Infineon Technologies. “These monolithically integrated, bidirectional GaN switches enable more efficient conversion in a smaller package since they are designed to control the flow of electricity in both directions,” explains a news item(opens in new window) posted on the website of Fraunhofer Institute for Reliability and Microintegration IZM, the partner overseeing the project’s automotive use case. A single GaN switch therefore does the work of two conventional semiconductors, reducing system complexity and laying the foundations for new technological opportunities. Fraunhofer’s expertise in packaging and system development has played a crucial role in optimising the entire OBC system. Rather than focusing on individual components, the HiPower 5.0 consortium adopted a holistic approach, embedding electronic components directly into circuit boards. This design shortens critical electrical paths, minimises potential energy losses and saves space, resulting in a highly integrated and efficient system.
Automotive and beyond
HiPower 5.0’s impact extends beyond the automotive sector. The project is also exploring applications in marine shipping, further leveraging the advantages of GaN and wide-bandgap semiconductors. Throughout the course of the project, the HiPower 5.0 team will be working on six use cases. These include next-generation bidirectional blocking switches that drastically reduce switching and conduction losses, hybrid multi-level automotive inverters that optimise efficiency and cost, and next-generation auxiliary converters for both passenger cars and heavy-duty vehicles. Another two use cases involve the development of fully integrated electric drive systems for greater efficiency, reliability and sustainability, and a digital twin of a three-level inverter based on GaN components. Last but not least, in the maritime domain, the project is exploring solutions involving an integrated inverter and e-motor, a high-power charging unit for ships, a 3 kV DC source with galvanic isolation and solid-state circuit breakers for DC grids on ships. The HiPower 5.0 (Leading edge Semiconductor, Integration, and Control System Technologies for highly compact and smart eDrive Components towards more sustainable Power Electronics 5.0) project’s innovations are tackling critical challenges in sustainable mobility and helping to pave the way to a low-carbon future. The project ends in 2028. For more information, please see: HiPower 5.0 project website(opens in new window)
