16 December 2021
VisIC and hofer powertrain develop 3-Level 800V GaN inverter in EVs
VisIC Technologies Ltd of Ness Ziona, Israel – a fabless supplier of power conversion devices based on gallium nitride (GaN) transistors – has partnered with automotive powertrain technology company hofer powertrain of Nürtingen, Germany to work jointly on a GaN-based inverter for 800V automotive applications.
“Our partnership with hofer powertrain for the development of gallium nitride-based power inverters in electric vehicles is the breakthrough of gallium nitride technology for 800V battery systems in the automotive industry,” says VisIC’s CEO Tamara Baksht. “VisIC’s D3GaN technology was developed for the high-reliability standards of the automotive industry and offers the lowest losses per RDS(on),” she claims. “It also simplifies the system solution and enables highly efficient and affordable powertrain platforms solutions. The ability to support cars with a 800V battery, along with the 400V battery, is a significant step forward in GaN’s worldwide adoption by automotive electrical drivelines.”
hofer powertrain has been working for more than five years on the development of 3-Level inverters for automotive powertrain applications, revealing vast benefits that the 3-Level topology brings compared to existing state-of-the-art 2-Level inverters using silicon insulated-gate bipolar transistors (IGBTs) or silicon carbide (SiC) chips. The special properties of the 3-L topology of an inverter lead to improved overall system energy consumption at the relevant reference driving cycles, such as WLTP, due to reduced harmonic losses in the motor. Moreover, the noise vibration harshness (NVH) behavior of the complete electric drive unit can be improved due to the better total harmonic distortion of the output current affecting noise reduction.
Finally, costs are reduced regarding electromagnetic compatibility measures to meet the increasingly strict requirements (such as Comité International Spécial des Perturbations Radioélectriques 25 class 5), due to the better common-mode behavior of the hofer powertrain 3-Level inverter.
GaN is the key to efficiency improvements and increasing the driving range of electric vehicles, notes VisIC. The technology offers significantly better switching speed and smaller and lighter package size, reducing total system cost.
Today’s GaN chips are used for 400V DC-link voltage and hofer powertrain 3-Level topology and, coupled with VisIC’s GaN benefits, will yield the next level of improvement in 800V powertrains. The synergy of both parties can be used for 3-Level topologies.
“Both technologies in combination allow us to apply the benefits of GaN and the benefits of the 3-L topology, and thereby multiply the benefits for our customers,” says Philipp Matt, Electronics expert at hofer powertrain.