Analysis and Conceptualization of a 800 V 100 kVA Full-GaN Three-Level Flying Capacitor Inverter for Next-Generation Electric Vehicle Drives

The rising pace of the transportation sector elec-trification is increasingly demanding for cheaper, lighter and more efficient powertrains. In particular, the inverter represents a crucial component of an electric vehicle (EV) drive train, being responsible for the DC/ AC power conversion between the battery and the electrical machine. Therefore, a great effort is currently being spent to develop a new generation of EV drive inverters, leveraging advanced converter topologies and modern wide bandgap (WBG) semiconductor devices. For instance, three-level inverters are particularly promising candidates for future 800 V powertrains, as they allow to exploit semiconductor devices with lower blocking voltage (i.e., 600/650 V) and higher switching performance, such as state-of-the-art GaN high electron mobility transistors (HEMTs). In this context, this paper proposes the analysis and the conceptualization of a full-GaN 100 kVA 800 V three-level flying capacitor inverter (3LFCI) for next-generation EV drives. A complete theoretical assessment of the system active and passive component stresses is carried out, providing the foun-dation for the converter sizing. Moreover, a 3LFCI design concept is developed, achieving an estimated 99.1 % peak semiconductor efficiency and 108kVA/dm³ volumetric power density.