Two Universities Unveil V2G-Capable OBC Designs Leveraging WBG Tech

Dec. 18, 2024

Industry and academia team to create designs for compact, cost-effective, V2G-capable onboard chargers for EVs.

What you’ll learn:

Researchers from two universities released innovative designs for onboard chargers that support vehicle-to-grid functionality
Developed in partnership with Infineon, they use the unique properties of SiC and GaN devices to create rugged designs that achieve power densities of over 3 kW/l.

Infineon Technologies collaborated with Silicon Austria Labs (SAL) and the Power Electronic Systems Laboratory at ETH Zurich to develop prototypes of vehicle-to-grid (V2G)-capable onboard chargers (OBCs). They integrate wide-bandgap (WBG) semiconductors to achieve their high efficiency and power density.

Silicon Austria Labs’s Tiny Box 1 prototype uses Infineon’s silicon-carbide (SiC) power devices to achieve the team’s goal of reducing the OBC’s weight, bill-of-materials count, and space while increasing power density by a factor of 4 over conventional designs. The result was a pair of two demonstrator variants:

A single-phase 7-kW OBC that was optimized for automotive applications. It uses a simple liquid-cooling system to achieve a power density of 3.1 kW/l (with housing) while delivering over 97% efficiency.
A three-phase 11-kW charger that was optimized for efficiency with passive/air cooling at voltage for electric forklift applications.

Silicon Austria Labs’s Tiny Box 1 prototype for V2G onboard chargers.

Additional information can be found within Infineon’s website, or SAL’s project homepage.

The Power Electronic Systems Laboratory at ETH Zurich developed a 10-kW bidirectional EV charger based on Infineon’s gallium-nitride (GaN) devices for its Vienna Rectifier PFC front-end and four cascaded dual active bridges (DABs) that serve as isolated DC-DC converter stages. Operating at switching frequencies of up to 550 kHz, the converter utilizes novel modulation schemes to reach a peak efficiency of 96% and a wide EV battery voltage range from 250 to 1,000 V_DC,out.

A 10-kW bidirectional EV charger developed by the Power Electronic Systems Laboratory at ETH Zurich incorporating Infineon GaN devices.

Additional information about this design is available on the project page on Infineon’s website. A high-resolution 3D model of the design can be viewed by clicking this link.

About the Author

Lee Goldberg | Contributing Editor

Lee Goldberg is a self-identified “Recovering Engineer,” Maker/Hacker, Green-Tech Maven, Aviator, Gadfly, and Geek Dad. He spent the first 18 years of his career helping design microprocessors, embedded systems, renewable energy applications, and the occasional interplanetary spacecraft. After trading his ‘scope and soldering iron for a keyboard and a second career as a tech journalist, he’s spent the next two decades at several print and online engineering publications.

Lee’s current focus is power electronics, especially the technologies involved with energy efficiency, energy management, and renewable energy. This dovetails with his coverage of sustainable technologies and various environmental and social issues within the engineering community that he began in 1996. Lee also covers 3D printers, open-source hardware, and other Maker/Hacker technologies.

Lee holds a BSEE in Electrical Engineering from Thomas Edison College, and participated in a colloquium on technology, society, and the environment at Goddard College’s Institute for Social Ecology. His book, “Green Electronics/Green Bottom Line - A Commonsense Guide To Environmentally Responsible Engineering and Management,” was published by Newnes Press.

Lee, his wife Catherine, and his daughter Anwyn currently reside in the outskirts of Princeton N.J., where they masquerade as a typical suburban family.

Lee also writes the regular PowerBites series.