GaN4EmoBiL project targets two-way charging
Fraunhofer IAF and partners to develop technologies to turn EVs into 'batteries on wheels'
Bidirectional charging could turn all EVs into 'batteries on wheels', increasing the flexibility of our wider energy ecosystem.
Now, to ensure that two-way charging can be used on a broad scale, a consortium led by Fraunhofer IAF, is researching potential new charging technologies for 800V class batteries.
Partners of the three year GaN4EmoBi project include the University of Stuttgart, Robert Bosch GmbH and Ambibox GmbH. The consortium’s goal is to demonstrate an intelligent and cost-effective bidirectional charging system using new power semiconductors, device concepts and system components.
“Our project aims to connect batteries, renewable energies and electrical consumers in an economical and flexible way. Through bidirectional charging solutions, the previously unused batteries of parking electric vehicles will make a greater contribution to increasing the flexibility of the energy system and avoiding CO2 emissions in the future,” says Stefan Monch, researcher in the field of power electronics at Fraunhofer IAF and project coordinator of GaN4EmoBiL.
“In future, efficient, small-scale and intelligent charging infrastructures in electromobility will contribute to overcoming social challenges”, says Etienne Tchonla, R&D director at Ambibox.
Today, bidirectional medium-power DC wallboxes for batteries up to 800V use power semiconductors that are either efficient but expensive (SiC) or low-cost but less efficient (silicon). Available 650V transistors made of GaN-on-Si are inexpensive and efficient, but require a complex circuit due to insufficient voltage rating.
To integrate as many batteries as possible bidirectionally, the cost, efficiency and compactness of charging solutions must be significantly improved. For this purpose, the project partners of GaN4EmoBiL are focusing on new semiconductor solutions as a first step. One idea is to develop GaN technology on alternative substrates (for example sapphire), which enables low-cost and efficient 1200 V transistors.
The project is funded by the German Federal Ministry of Economic Affairs and Climate Action (BMWK) as part of the Elektro-Mobil program.