A 10-Level Flying Capacitor Multi-Level Dual-Interleaved Power Module for Scalable and Power-Dense Electric Drives

The adoption of cleaner vehicle technologies is predicated on the development of efficient and power-dense electric drives. Recent activity in this area has produced several high performance converters geared towards this application. While much effort has been focused on improving traditional concepts, others have sought more unconventional topologies to attain high performance as well as system level benefits–such as reduced output current distortion, dv/dt and filter size. This work represents the latter approach, using the flying capacitor multilevel topology (FCML) in a high-power, high-voltage, gallium nitride (GaN)-based inverter. Specific design considerations are reviewed, and take into account recent developments in component characterization and thermal management, followed by a discussion of start-up and steady-state operation. A 10-level prototype FCML inverter is used to demonstrate operation at 1 kV dc input voltage and 13.4 kW peak output power, with 26.7 kW/kg and 17.4 kW/L power densities.