This paper presents a cutting-edge automotive inverter technology designed to achieve highest efficiency in electric vehicle (EV) powertrains targeting “SiC performance @Silicon costs”.
The inverter power core is based on 650V D-mode GaN HEMT technology D³GaN (Direct Drive D-mode technology) that combines lowest switching losses and excellent gate robustness. Direct gate control of the HEMT enables current scaling by paralleling GaN devices while keeping control of slew rate which is important for inverter control
In collaboration with NXP a dedicated D³GaN gate driver IC is under development (GD3171), which provides diagnosis and safety functions. It allows for optimal utilization of D³GaN potential and is improving switching losses
The new features include reduced PWM dead-time compared to traditional GaN gate drivers, GaN-specific real-time Vgs monitoring, and new Overcurrent Protection (OCP) and Short-Circuit Protection (SCP) strategies replacing the standard Desat method. They are targeted to comply with ASIL-D requirements in automotive traction.
The inverter peak efficiency amounts to more than 99.5%. Results from dynamometer testing confirm that D³GaN based inverter power cores significantly improve the overall driving cycle efficiency of EVs, contributing to longer driving range, and improved vehicle performance. Thus, this breakthrough technology marks a key advancement in the pursuit of sustainable, high-performance electric mobility.
This implementation is heading for a sustainable, highest efficient and cost-effective traction inverter solution, serving the functional and safety requirements from the beginning.